diff --git a/canvas/src/components/__tests__/TestConnectionButton.test.tsx b/canvas/src/components/__tests__/TestConnectionButton.test.tsx
index 15f1dd9cf..b4dd0cda0 100644
--- a/canvas/src/components/__tests__/TestConnectionButton.test.tsx
+++ b/canvas/src/components/__tests__/TestConnectionButton.test.tsx
@@ -11,13 +11,21 @@ import { render, screen, fireEvent, cleanup, act } from "@testing-library/react"
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { TestConnectionButton } from "../ui/TestConnectionButton";
 import type { SecretGroup } from "@/types/secrets";
-import { validateSecret } from "@/lib/api/secrets";
+import { validateSecret, ApiError } from "@/lib/api/secrets";
 
 // ─── Mock validateSecret ──────────────────────────────────────────────────────
 // vi.mock is hoisted, so validateSecret (imported above) refers to the mocked
 // namespace value once vi.mock runs. Use vi.mocked() to access it in tests.
 vi.mock("@/lib/api/secrets", () => ({
   validateSecret: vi.fn(),
+  ApiError: class ApiError extends Error {
+    status: number;
+    constructor(status: number, message: string) {
+      super(message);
+      this.name = "ApiError";
+      this.status = status;
+    }
+  },
 }));
 
 // SecretGroup is a string literal type: 'github' | 'anthropic' | 'openrouter' | 'custom'
@@ -102,7 +110,7 @@ describe("TestConnectionButton — state machine", () => {
     expect(screen.getByText("Permission denied")).toBeTruthy();
   });
 
-  it("shows generic error message on unexpected exception", async () => {
+  it("shows a connectivity message on a genuine network exception", async () => {
     vi.mocked(validateSecret).mockRejectedValue(new Error("timeout"));
     render(<TestConnectionButton provider={toGroup("anthropic")} secretValue="sk-..." />);
 
@@ -110,8 +118,23 @@ describe("TestConnectionButton — state machine", () => {
     await act(async () => { /* flush */ });
 
     expect(screen.getByRole("alert")).toBeTruthy();
-    // The error detail is hardcoded to "Connection timed out. Service may be down."
-    expect(document.body.querySelector('[role="alert"]')?.textContent).toMatch(/timed out/i);
+    // A real thrown network error → honest connectivity message (not a
+    // fabricated "service down"); see internal#492.
+    expect(document.body.querySelector('[role="alert"]')?.textContent).toMatch(
+      /could not reach the validation service/i,
+    );
+  });
+
+  it("does not claim a timeout when the validate endpoint 404s (internal#492)", async () => {
+    vi.mocked(validateSecret).mockRejectedValue(new ApiError(404, "Not Found"));
+    render(<TestConnectionButton provider={toGroup("anthropic")} secretValue="sk-..." />);
+
+    fireEvent.click(screen.getByRole("button"));
+    await act(async () => { /* flush */ });
+
+    const alert = document.body.querySelector('[role="alert"]')?.textContent ?? "";
+    expect(alert).not.toMatch(/timed out/i);
+    expect(alert).toMatch(/not available/i);
   });
 });
 
diff --git a/canvas/src/components/mobile/MobileChat.tsx b/canvas/src/components/mobile/MobileChat.tsx
index 375bd37a8..b5940a0ea 100644
--- a/canvas/src/components/mobile/MobileChat.tsx
+++ b/canvas/src/components/mobile/MobileChat.tsx
@@ -2,8 +2,11 @@
 
 // 04 · Chat — message thread + composer + sub-tabs.
 // Wired to the same /workspaces/:id/a2a (method message/send) endpoint
-// that the desktop ChatTab uses, but with a slimmer surface: no
-// attachments, no A2A topology overlay, no conversation tracing.
+// that the desktop ChatTab uses. Render parity with desktop ChatTab is
+// achieved by reusing its renderers rather than forking a reduced
+// mobile path: the Agent Comms sub-tab mounts the same AgentCommsPanel,
+// and message attachments route through the same AttachmentPreview
+// dispatch the desktop My-Chat bubble uses (#231/#232).
 
 import { useEffect, useMemo, useRef, useState } from "react";
 import ReactMarkdown from "react-markdown";
@@ -16,6 +19,9 @@ import {
   useChatSend,
   useChatSocket,
 } from "@/components/tabs/chat/hooks";
+import { AgentCommsPanel } from "@/components/tabs/chat/AgentCommsPanel";
+import { AttachmentPreview } from "@/components/tabs/chat/AttachmentPreview";
+import { downloadChatFile } from "@/components/tabs/chat/uploads";
 
 import { toMobileAgent } from "./components";
 import { MOBILE_FONT_MONO, MOBILE_FONT_SANS, usePalette } from "./palette";
@@ -304,6 +310,17 @@ export function MobileChat({
   const removePendingFile = (index: number) =>
     setPendingFiles((prev) => prev.filter((_, i) => i !== index));
 
+  // Route attachment downloads through the same authenticated helper
+  // the desktop ChatTab uses (downloadChatFile) so platform-scheme
+  // URIs get a real Blob with auth headers instead of about:blank.
+  const downloadAttachment = (att: ChatAttachment) => {
+    downloadChatFile(agentId, att).catch(() => {
+      // AttachmentPreview's own error affordance covers the in-bubble
+      // failure state; matches ChatTab's behaviour of not double-
+      // reporting a download failure.
+    });
+  };
+
   const send = async () => {
     const text = draft.trim();
     if ((!text && pendingFiles.length === 0) || sending || !reachable) return;
@@ -433,7 +450,19 @@ export function MobileChat({
         </div>
       </div>
 
+      {/* Agent Comms — reuse the desktop AgentCommsPanel verbatim so
+          mobile renders the identical peer/A2A + delegation feed
+          (history GET + live socket events) instead of a placeholder
+          (#231). The panel owns its own scroll/load/error/empty
+          states, matching ChatTab's agent-comms tabpanel. */}
+      {tab === "a2a" && (
+        <div style={{ flex: 1, minHeight: 0, overflow: "hidden" }}>
+          <AgentCommsPanel workspaceId={agentId} />
+        </div>
+      )}
+
       {/* Messages */}
+      {tab === "my" && (
       <div
         ref={scrollRef}
         style={{
@@ -445,18 +474,6 @@ export function MobileChat({
           gap: 8,
         }}
       >
-        {tab === "a2a" && (
-          <div
-            style={{
-              padding: "20px 4px",
-              textAlign: "center",
-              color: p.text3,
-              fontSize: 13,
-            }}
-          >
-            Agent Comms — peer-to-peer A2A traffic surfaces in the Comms tab.
-          </div>
-        )}
         {tab === "my" && historyLoading && (
           <div style={{ padding: "20px 4px", textAlign: "center", color: p.text3, fontSize: 13 }}>
             Loading chat history…
@@ -521,9 +538,31 @@ export function MobileChat({
                     overflowWrap: "anywhere",
                   }}
                 >
-                  <MarkdownBubble dark={dark} accent={p.accent}>
-                    {m.content}
-                  </MarkdownBubble>
+                  {m.content && (
+                    <MarkdownBubble dark={dark} accent={p.accent}>
+                      {m.content}
+                    </MarkdownBubble>
+                  )}
+                  {m.attachments && m.attachments.length > 0 && (
+                    <div
+                      style={{
+                        display: "flex",
+                        flexWrap: "wrap",
+                        gap: 4,
+                        marginTop: m.content ? 6 : 0,
+                      }}
+                    >
+                      {m.attachments.map((att, i) => (
+                        <AttachmentPreview
+                          key={`${m.id}-${i}`}
+                          workspaceId={agentId}
+                          attachment={att}
+                          onDownload={downloadAttachment}
+                          tone={mine ? "user" : "agent"}
+                        />
+                      ))}
+                    </div>
+                  )}
                   <div
                     style={{
                       fontSize: 10,
@@ -554,7 +593,13 @@ export function MobileChat({
           </div>
         )}
       </div>
+      )}
 
+      {/* Footer ID + composer belong to My Chat only. The Agent Comms
+          tab is a read-only peer/A2A feed (parity with desktop
+          ChatTab, where the agent-comms tabpanel has no composer). */}
+      {tab === "my" && (
+      <>
       {/* Footer ID */}
       <div
         style={{
@@ -746,6 +791,8 @@ export function MobileChat({
           </button>
         </div>
       </div>
+      </>
+      )}
     </div>
   );
 }
diff --git a/canvas/src/components/mobile/__tests__/MobileChat.test.tsx b/canvas/src/components/mobile/__tests__/MobileChat.test.tsx
index 7a0a8ca12..0c8e24595 100644
--- a/canvas/src/components/mobile/__tests__/MobileChat.test.tsx
+++ b/canvas/src/components/mobile/__tests__/MobileChat.test.tsx
@@ -21,6 +21,14 @@ import { MobileChat } from "../MobileChat";
 vi.mock("@/lib/api");
 import { api } from "@/lib/api";
 
+// AgentCommsPanel (mounted by the Agent Comms sub-tab, #231) subscribes
+// to the global socket via useSocketEvent. Stub it to a no-op so the
+// panel mounts without the real ReconnectingSocket — the parity tests
+// only assert the panel renders (vs the old static placeholder).
+vi.mock("@/hooks/useSocketEvent", () => ({
+  useSocketEvent: vi.fn(),
+}));
+
 // ─── Mock store ───────────────────────────────────────────────────────────────
 
 const mockAgentId = "ws-chat-test";
@@ -155,6 +163,12 @@ beforeEach(() => {
   mockOnBack.mockClear();
   mockStoreState.nodes = [];
   mockStoreState.agentMessages = {};
+  // jsdom doesn't implement scrollIntoView. The Agent Comms tab now
+  // mounts AgentCommsPanel (#231), which scrolls its feed to bottom on
+  // arrival; a no-op stub keeps the panel from throwing under jsdom
+  // (same stub AgentCommsPanel's own render test installs).
+  Element.prototype.scrollIntoView =
+    vi.fn() as unknown as Element["scrollIntoView"];
   // Set up spies on the real api methods. Tests override these per-call.
   const getSpy = vi.spyOn(api, "get");
   const postSpy = vi.spyOn(api, "post");
@@ -474,3 +488,146 @@ describe("MobileChat — chat history", () => {
     expect(getSpy).toHaveBeenCalledTimes(2);
   });
 });
+
+// ─── #232 · Attachment render parity with desktop ChatTab ────────────────────
+//
+// Regression for the CTO-reported mobile bug: MobileChat used to render
+// only m.content (no attachment surface), so files sent/received in a
+// conversation were invisible on mobile while desktop showed them. The
+// fix routes m.attachments through the same AttachmentPreview the
+// desktop ChatTab bubble uses.
+
+describe("MobileChat — attachment render parity (#232)", () => {
+  beforeEach(() => {
+    mockStoreState.nodes = [onlineNode];
+  });
+
+  it("renders an attachment from a history message via AttachmentPreview", async () => {
+    const getSpy = vi.spyOn(api, "get");
+    // useChatHistory reads { messages, reached_end }.
+    getSpy.mockResolvedValueOnce({
+      messages: [
+        {
+          id: "m-att-1",
+          role: "agent",
+          content: "Here is the report",
+          attachments: [
+            {
+              name: "report.csv",
+              uri: "workspace://out/report.csv",
+              mimeType: "text/csv",
+              size: 2048,
+            },
+          ],
+          timestamp: new Date().toISOString(),
+        },
+      ],
+      reached_end: true,
+    });
+
+    let rr: ReturnType<typeof renderChat>;
+    await act(async () => {
+      rr = renderChat(mockAgentId);
+    });
+    const { container } = rr!;
+
+    // A non-image attachment renders the AttachmentChip download button
+    // with title="Download <name>" — same component the desktop bubble
+    // dispatches through AttachmentPreview.
+    await waitFor(() => {
+      const chip = container.querySelector('[title="Download report.csv"]');
+      expect(chip).toBeTruthy();
+    });
+    expect(container.textContent ?? "").toContain("report.csv");
+  });
+});
+
+// ─── #231 · Agent Comms (A2A/peer) render parity with desktop ChatTab ────────
+//
+// Regression for the CTO-reported mobile bug: the Agent Comms sub-tab
+// rendered a static placeholder string ("peer-to-peer A2A traffic
+// surfaces in the Comms tab") instead of the real feed. The fix mounts
+// the same AgentCommsPanel the desktop ChatTab agent-comms tabpanel
+// uses, so peer/A2A + delegation activity is visible on mobile.
+
+describe("MobileChat — Agent Comms render parity (#231)", () => {
+  beforeEach(() => {
+    mockStoreState.nodes = [onlineNode];
+  });
+
+  it("mounts AgentCommsPanel on the Agent Comms tab (not the old placeholder)", async () => {
+    const getSpy = vi.spyOn(api, "get");
+    // 1st GET: useChatHistory (My Chat) on mount.
+    getSpy.mockResolvedValueOnce({ messages: [], reached_end: true });
+    // 2nd GET: AgentCommsPanel's activity load when the tab is shown.
+    // Empty list → panel renders its own empty state, which still
+    // proves AgentCommsPanel mounted (vs. the removed placeholder).
+    getSpy.mockResolvedValueOnce([]);
+
+    let rr: ReturnType<typeof renderChat>;
+    await act(async () => {
+      rr = renderChat(mockAgentId);
+    });
+    const { container } = rr!;
+
+    const commsTab = Array.from(container.querySelectorAll("button")).find(
+      (b) => b.textContent?.trim() === "Agent Comms",
+    );
+    expect(commsTab).toBeTruthy();
+    await act(async () => {
+      commsTab!.click();
+    });
+
+    await waitFor(() => {
+      const text = container.textContent ?? "";
+      // The panel's empty state — proves AgentCommsPanel mounted.
+      expect(text).toContain("No agent-to-agent communications yet.");
+    });
+    // The old hard-coded placeholder must be gone.
+    expect(container.textContent ?? "").not.toContain(
+      "peer-to-peer A2A traffic surfaces in the Comms tab",
+    );
+    // The panel hit its activity endpoint.
+    expect(getSpy).toHaveBeenCalledWith(
+      expect.stringContaining(`/workspaces/${mockAgentId}/activity`),
+    );
+  });
+
+  it("renders a peer message on the Agent Comms tab", async () => {
+    const getSpy = vi.spyOn(api, "get");
+    getSpy.mockResolvedValueOnce({ messages: [], reached_end: true });
+    // a2a_receive from a peer → AgentCommsPanel.toCommMessage maps it
+    // to an inbound bubble with the request text.
+    getSpy.mockResolvedValueOnce([
+      {
+        id: "act-1",
+        activity_type: "a2a_receive",
+        source_id: "peer-ws-uuid",
+        target_id: mockAgentId,
+        method: "message/send",
+        summary: "peer asked something",
+        request_body: { task: "Please review PR 42" },
+        response_body: null,
+        status: "ok",
+        created_at: new Date().toISOString(),
+      },
+    ]);
+
+    let rr: ReturnType<typeof renderChat>;
+    await act(async () => {
+      rr = renderChat(mockAgentId);
+    });
+    const { container } = rr!;
+
+    const commsTab = Array.from(container.querySelectorAll("button")).find(
+      (b) => b.textContent?.trim() === "Agent Comms",
+    );
+    await act(async () => {
+      commsTab!.click();
+    });
+
+    await waitFor(() => {
+      expect(container.textContent ?? "").toContain("Please review PR 42");
+    });
+  });
+});
diff --git a/canvas/src/components/settings/SecretRow.tsx b/canvas/src/components/settings/SecretRow.tsx
index 92bb633ea..10339e869 100644
--- a/canvas/src/components/settings/SecretRow.tsx
+++ b/canvas/src/components/settings/SecretRow.tsx
@@ -3,16 +3,24 @@ import { useState, useCallback, useRef, useEffect } from 'react';
 import type { Secret, SecretGroup } from '@/types/secrets';
 import { useSecretsStore } from '@/stores/secrets-store';
 import { StatusBadge } from '@/components/ui/StatusBadge';
-import { RevealToggle } from '@/components/ui/RevealToggle';
 import { KeyValueField } from '@/components/ui/KeyValueField';
 import { ValidationHint } from '@/components/ui/ValidationHint';
 import { TestConnectionButton } from '@/components/ui/TestConnectionButton';
 import { validateSecretValue } from '@/lib/validation/secret-formats';
 import { SERVICES } from '@/lib/services';
 
-const AUTO_HIDE_MS = 30_000;
 const VALIDATION_DEBOUNCE_MS = 400;
 
+// Secret values are write-only from the browser: the server List endpoint
+// "Never exposes values", there is no per-secret decrypt route, and the
+// only decrypted path (GET /secrets/values) is bulk + token-gated for
+// remote agents. The old eye/RevealToggle was a dead affordance — it
+// flipped its own icon but could never reveal anything, which read as
+// "this doesn't work" (esp. once clicked → eye-with-slash). We show an
+// honest static indicator instead; rotation is via Edit.
+const WRITE_ONLY_TITLE =
+  'Value is write-only and cannot be revealed — use Edit to replace/rotate it';
+
 interface SecretRowProps {
   secret: Secret;
   workspaceId: string;
@@ -31,28 +39,12 @@ export function SecretRow({ secret, workspaceId }: SecretRowProps) {
   const setSecretStatus = useSecretsStore((s) => s.setSecretStatus);
 
   const isEditing = editingKey === secret.name;
-  const [revealed, setRevealed] = useState(false);
   const [editValue, setEditValue] = useState('');
   const [validationError, setValidationError] = useState<string | null>(null);
   const [isSaving, setIsSaving] = useState(false);
   const [saveError, setSaveError] = useState<string | null>(null);
   const debounceRef = useRef<ReturnType<typeof setTimeout>>(undefined);
   const editBtnRef = useRef<HTMLButtonElement>(null);
-  const revealTimerRef = useRef<ReturnType<typeof setTimeout>>(undefined);
-
-  // Auto-hide revealed value after 30s
-  useEffect(() => {
-    if (revealed) {
-      clearTimeout(revealTimerRef.current);
-      revealTimerRef.current = setTimeout(() => setRevealed(false), AUTO_HIDE_MS);
-      return () => clearTimeout(revealTimerRef.current);
-    }
-  }, [revealed]);
-
-  // Reset revealed state when panel closes (session-only)
-  useEffect(() => {
-    return () => setRevealed(false);
-  }, []);
 
   // Debounced validation
   useEffect(() => {
@@ -133,11 +125,15 @@ export function SecretRow({ secret, workspaceId }: SecretRowProps) {
           {secret.masked_value}
         </span>
         <div className="secret-row__actions">
-          <RevealToggle
-            revealed={revealed}
-            onToggle={() => setRevealed((r) => !r)}
-            label={`Toggle reveal ${secret.name}`}
-          />
+          <span
+            data-testid="write-only-indicator"
+            className="secret-row__write-only"
+            role="img"
+            aria-label={`${secret.name} value is write-only and cannot be revealed; use Edit to replace it`}
+            title={WRITE_ONLY_TITLE}
+          >
+            🔒
+          </span>
           <StatusBadge status={secret.status} />
           <button
             type="button"
diff --git a/canvas/src/components/settings/TokensTab.tsx b/canvas/src/components/settings/TokensTab.tsx
index 092e4df56..5210b8a17 100644
--- a/canvas/src/components/settings/TokensTab.tsx
+++ b/canvas/src/components/settings/TokensTab.tsx
@@ -16,7 +16,40 @@ interface TokensTabProps {
   workspaceId: string;
 }
 
+// The settings panel passes the literal sentinel "global" when no canvas
+// node is selected. Workspace tokens are inherently per-workspace — there
+// is no /workspaces/global/tokens endpoint (querying the uuid column with
+// "global" 500s on Postgres). The org-wide equivalent lives in the
+// separate "Org API Keys" tab. Mirrors the sentinel-awareness that
+// api/secrets.ts already has (workspaceId === 'global' → /settings/secrets).
+const GLOBAL_WORKSPACE_ID = 'global';
+
 export function TokensTab({ workspaceId }: TokensTabProps) {
+  if (workspaceId === GLOBAL_WORKSPACE_ID) {
+    return (
+      <div className="p-4 space-y-4">
+        <div>
+          <h3 className="text-sm font-semibold text-ink">API Tokens</h3>
+          <p className="text-[10px] text-ink-mid mt-0.5">
+            Bearer tokens for authenticating API calls to this workspace.
+          </p>
+        </div>
+        <div className="text-center py-6">
+          <p className="text-xs text-ink-mid">Select a workspace node first</p>
+          <p className="text-[10px] text-ink-mid mt-1">
+            Workspace tokens are scoped to a single workspace. Select a node
+            on the canvas to manage its tokens, or use the{' '}
+            <span className="text-accent font-medium">Org API Keys</span> tab
+            for org-wide API keys.
+          </p>
+        </div>
+      </div>
+    );
+  }
+  return <WorkspaceTokensTab workspaceId={workspaceId} />;
+}
+
+function WorkspaceTokensTab({ workspaceId }: TokensTabProps) {
   const [tokens, setTokens] = useState<Token[]>([]);
   const [loading, setLoading] = useState(true);
   const [creating, setCreating] = useState(false);
diff --git a/canvas/src/components/settings/__tests__/SecretRow.test.tsx b/canvas/src/components/settings/__tests__/SecretRow.test.tsx
index 1db10a82b..6763355be 100644
--- a/canvas/src/components/settings/__tests__/SecretRow.test.tsx
+++ b/canvas/src/components/settings/__tests__/SecretRow.test.tsx
@@ -138,14 +138,54 @@ describe("SecretRow — display mode", () => {
     expect(document.querySelector('[role="row"]')).toBeTruthy();
   });
 
-  it("has Reveal, Copy, Edit, Delete buttons", () => {
+  it("has Copy, Edit, Delete buttons", () => {
     render(<SecretRow secret={GITHUB_SECRET} workspaceId="ws-1" />);
-    expect(screen.getByTestId("reveal-toggle")).toBeTruthy();
     expect(screen.getByRole("button", { name: /copy/i })).toBeTruthy();
     expect(screen.getByRole("button", { name: /edit/i })).toBeTruthy();
     expect(screen.getByRole("button", { name: /delete/i })).toBeTruthy();
   });
 
+  // Regression: the reveal/eye control was a dead affordance. Clicking it
+  // flipped its own icon (eye → eye-with-slash) but never revealed the value,
+  // because secret values are write-only from the browser (server List
+  // "Never exposes values"; there is no per-secret decrypt endpoint and the
+  // client has no plaintext-fetch function). The honest fix removes the
+  // toggle and shows a static "write-only / cannot be revealed" indicator.
+  // See internal tracking issue + internal#210/#211.
+  it("does NOT render a reveal/eye toggle (values are write-only)", () => {
+    render(<SecretRow secret={GITHUB_SECRET} workspaceId="ws-1" />);
+    expect(screen.queryByTestId("reveal-toggle")).toBeNull();
+    expect(
+      screen.queryByRole("button", { name: /toggle reveal/i }),
+    ).toBeNull();
+  });
+
+  it("shows a write-only indicator explaining the value cannot be revealed", () => {
+    render(<SecretRow secret={ANTHROPIC_SECRET} workspaceId="ws-1" />);
+    const indicator = screen.getByTestId("write-only-indicator");
+    expect(indicator).toBeTruthy();
+    // Affordance must be honest: explain it cannot be revealed and that
+    // Edit is the rotate path. It must not be a clickable button.
+    const title = indicator.getAttribute("title") ?? "";
+    expect(title.toLowerCase()).toMatch(/write-only|cannot be revealed/);
+    expect(indicator.tagName).not.toBe("BUTTON");
+  });
+
+  it("write-only indicator is present for the Anthropic/OAuth-token row too", () => {
+    // The reported bug singled out CLAUDE_CODE_OAUTH_TOKEN (anthropic group);
+    // the fix is group-agnostic — every row gets the same honest affordance.
+    const OAUTH_SECRET = {
+      name: "CLAUDE_CODE_OAUTH_TOKEN",
+      masked_value: "••••••••••••••••9d2a",
+      group: "anthropic" as const,
+      status: "unverified" as const,
+      updated_at: "2024-01-04",
+    };
+    render(<SecretRow secret={OAUTH_SECRET} workspaceId="ws-1" />);
+    expect(screen.queryByTestId("reveal-toggle")).toBeNull();
+    expect(screen.getByTestId("write-only-indicator")).toBeTruthy();
+  });
+
   it("shows invalid status correctly", () => {
     render(<SecretRow secret={CUSTOM_SECRET} workspaceId="ws-1" />);
     expect(screen.getByTestId("status-badge").getAttribute("data-status")).toBe("invalid");
diff --git a/canvas/src/components/settings/__tests__/TokensTab.test.tsx b/canvas/src/components/settings/__tests__/TokensTab.test.tsx
index cb923de55..f9409583b 100644
--- a/canvas/src/components/settings/__tests__/TokensTab.test.tsx
+++ b/canvas/src/components/settings/__tests__/TokensTab.test.tsx
@@ -302,3 +302,35 @@ describe("TokensTab — error", () => {
     expect(document.querySelector('[role="status"]')).toBeNull();
   });
 });
+
+// ─── "global" sentinel (no node selected) ────────────────────────────────────
+//
+// Regression: SettingsPanel passes the literal "global" when no canvas
+// node is selected. workspace tokens are per-workspace and there is no
+// /workspaces/global/tokens endpoint — calling it 500'd
+// ("invalid input syntax for type uuid: global"). The tab must NOT call
+// the API in that state and must point the user at the Org API Keys tab.
+describe("TokensTab — global sentinel (no node selected)", () => {
+  beforeEach(() => {
+    mockApiGet.mockReset();
+    mockApiPost.mockReset();
+    mockApiGet.mockRejectedValue(new Error("should not be called"));
+  });
+
+  it("does not call the API and shows a pointer to Org API Keys", async () => {
+    render(<TokensTab workspaceId="global" />);
+    await flush();
+    expect(mockApiGet).not.toHaveBeenCalled();
+    expect(mockApiPost).not.toHaveBeenCalled();
+    expect(document.body.textContent).toContain("Select a workspace node");
+    expect(document.body.textContent).toContain("Org API Keys");
+    // No error banner, no scary 500 surfacing.
+    expect(document.querySelector(".text-bad")).toBeNull();
+  });
+
+  it("has no create button in the global state", async () => {
+    render(<TokensTab workspaceId="global" />);
+    await flush();
+    expect(document.body.textContent).not.toContain("New Token");
+  });
+});
diff --git a/canvas/src/components/tabs/FilesTab.tsx b/canvas/src/components/tabs/FilesTab.tsx
index caf222795..196551da4 100644
--- a/canvas/src/components/tabs/FilesTab.tsx
+++ b/canvas/src/components/tabs/FilesTab.tsx
@@ -45,11 +45,54 @@ export function FilesTab({ workspaceId, data }: Props) {
   if (data && isExternalLikeRuntime(data.runtime)) {
     return <NotAvailablePanel runtime={data.runtime} />;
   }
-  return <PlatformOwnedFilesTab workspaceId={workspaceId} />;
+  return <PlatformOwnedFilesTab workspaceId={workspaceId} runtime={data?.runtime} />;
 }
 
-function PlatformOwnedFilesTab({ workspaceId }: { workspaceId: string }) {
-  const [root, setRoot] = useState("/configs");
+/** Picks the initial root for the FilesTab dropdown based on the
+ *  workspace's runtime. Decision: per-runtime default (Hongming
+ *  2026-05-15, internal#425 Decisions §2).
+ *
+ *  - openclaw → `/agent-home` (the agent's identity/state — the
+ *    user-facing interesting files for that runtime live in
+ *    `~/.openclaw/` inside the container, which `/agent-home` maps to
+ *    via the Phase 2b docker-exec backend).
+ *  - everything else (claude-code, hermes, external-like, undefined)
+ *    → `/configs` (the legacy default — managed config that flows
+ *    through the per-runtime indirection in
+ *    workspace-server/internal/handlers/template_files_eic.go).
+ *
+ *  When the runtime is undefined (legacy callers that don't thread
+ *  `data` through, or a workspace whose runtime field hasn't loaded
+ *  yet) the default is `/configs` — matches today's behaviour, no
+ *  surprise.
+ *
+ *  Note on `/agent-home` pre-Phase-2b: the backend short-circuits
+ *  with HTTP 501 and the canonical "implementation pending" body.
+ *  The tab renders empty + the error banner explains. This is by
+ *  design — lets us land the canvas UX before the backend ships,
+ *  per the RFC's phased rollout. The 501 is graceful: it doesn't
+ *  poison error toasts or generate "workspace not found" noise.
+ *
+ *  Adding a new runtime that should default to `/agent-home`: add it
+ *  to the agentHomeDefaultRuntimes set below. Adding a runtime that
+ *  should default to a different root: extend this function. */
+const agentHomeDefaultRuntimes = new Set(["openclaw"]);
+
+function defaultRootForRuntime(runtime: string | undefined): string {
+  if (runtime && agentHomeDefaultRuntimes.has(runtime)) {
+    return "/agent-home";
+  }
+  return "/configs";
+}
+
+function PlatformOwnedFilesTab({
+  workspaceId,
+  runtime,
+}: {
+  workspaceId: string;
+  runtime?: string;
+}) {
+  const [root, setRoot] = useState(() => defaultRootForRuntime(runtime));
   const [selectedFile, setSelectedFile] = useState<string | null>(null);
   const [fileContent, setFileContent] = useState("");
   const [editContent, setEditContent] = useState("");
diff --git a/canvas/src/components/tabs/FilesTab/FileEditor.tsx b/canvas/src/components/tabs/FilesTab/FileEditor.tsx
index db5301c5d..3e51356e6 100644
--- a/canvas/src/components/tabs/FilesTab/FileEditor.tsx
+++ b/canvas/src/components/tabs/FilesTab/FileEditor.tsx
@@ -3,6 +3,22 @@
 import { useRef } from "react";
 import { getIcon } from "./tree";
 
+// secretShapeMarker is the canonical body the workspace-server Files
+// API returns when a file's path OR content matched a credential
+// regex (internal#425 RFC, Phase 2b — backed by
+// workspace-server/internal/secrets.ScanBytes). The marker is a
+// fixed prefix so the canvas can detect it without parsing JSON and
+// without round-tripping the matched bytes through the editor (which
+// would defeat the purpose — clipboard, browser history, log
+// surfaces would all see them).
+//
+// Today (Phase 1 / before 2b ships) the backend returns 501 for the
+// only root that uses this path, so the marker is dead code until
+// 2b lands. Wiring it in now keeps the canvas + backend contracts
+// aligned in one PR rather than a follow-up. The constant is
+// importable so a future test can pin the exact string.
+export const SECRET_SHAPE_DENIED_MARKER = "<denied: secret-shape>";
+
 interface Props {
   selectedFile: string | null;
   fileContent: string;
@@ -31,6 +47,22 @@ export function FileEditor({
   const editorRef = useRef<HTMLTextAreaElement>(null);
   const isDirty = editContent !== fileContent;
 
+  // internal#425 Phase 3: detect the secret-shape denial marker and
+  // render a placeholder instead of the editor. The marker comes
+  // from workspace-server Phase 2b (secrets.ScanBytes) which refuses
+  // to surface the file's bytes. We deliberately don't expose
+  // the matched pattern's Name here — the canvas just shows the
+  // generic denial. The Files API log surface has the Pattern.Name
+  // for operators who need to debug a false positive.
+  const isSecretShapeDenied = fileContent === SECRET_SHAPE_DENIED_MARKER;
+
+  // /agent-home is read-only from the canvas (Phase 2b ships read +
+  // delete; Phase-2b-followup may add write). Edits to /configs are
+  // unchanged. Until 2b ships, /agent-home returns 501 so this
+  // read-only gate is also dead code, but wiring it in now keeps
+  // the UI honest the moment 2b lands without a follow-up canvas PR.
+  const isReadOnlyRoot = root !== "/configs";
+
   if (!selectedFile) {
     return (
       <div className="flex-1 flex items-center justify-center">
@@ -75,11 +107,42 @@ export function FileEditor({
       {/* Editor area */}
       {loadingFile ? (
         <div className="p-4 text-xs text-ink-mid">Loading...</div>
+      ) : isSecretShapeDenied ? (
+        // Files API refused to surface this file's bytes because its
+        // path or content matched a credential regex
+        // (workspace-server/internal/secrets, internal#425 Phase 2b).
+        // We render a placeholder INSTEAD OF the textarea so the
+        // matched bytes never enter the DOM. Clipboard / view-source
+        // / element-inspector all see the placeholder, not the
+        // credential.
+        <div
+          role="region"
+          aria-label="File content denied"
+          className="flex-1 flex items-center justify-center p-6 bg-surface"
+        >
+          <div className="max-w-md text-center space-y-2">
+            <div className="text-2xl opacity-40">🛡️</div>
+            <p className="text-[11px] font-mono text-warm">
+              {SECRET_SHAPE_DENIED_MARKER}
+            </p>
+            <p className="text-[10px] text-ink-mid leading-relaxed">
+              The platform refused to surface this file because its
+              path or content matched a credential-shape pattern.
+              The bytes never left the workspace container.
+            </p>
+            <p className="text-[10px] text-ink-mid leading-relaxed">
+              If this is a false positive (test fixture, docs example,
+              or content that happens to share a credential's shape),
+              rename the file or adjust the content via the workspace
+              terminal so the regex no longer matches, then refresh.
+            </p>
+          </div>
+        </div>
       ) : (
         <textarea
           ref={editorRef}
           value={editContent}
-          readOnly={root !== "/configs"}
+          readOnly={isReadOnlyRoot}
           onChange={(e) => setEditContent(e.target.value)}
           onKeyDown={(e) => {
             if ((e.metaKey || e.ctrlKey) && e.key === "s") {
diff --git a/canvas/src/components/tabs/FilesTab/FilesToolbar.tsx b/canvas/src/components/tabs/FilesTab/FilesToolbar.tsx
index dcdbba139..6ed193140 100644
--- a/canvas/src/components/tabs/FilesTab/FilesToolbar.tsx
+++ b/canvas/src/components/tabs/FilesTab/FilesToolbar.tsx
@@ -38,6 +38,15 @@ export function FilesToolbar({
           <option value="/home">/home</option>
           <option value="/workspace">/workspace</option>
           <option value="/plugins">/plugins</option>
+          {/* internal#425 Phase 1+3: container-internal $HOME root.
+              Backend lands the docker-exec dispatch in Phase 2b. Until
+              then the stub returns 501 with a canonical
+              "implementation pending" message — the dropdown renders
+              the option so the canvas affordance is design-frozen
+              even before the backend ships.
+              Runtime-default selection logic in FilesTab.tsx picks
+              this as the initial value for openclaw workspaces. */}
+          <option value="/agent-home">/agent-home</option>
         </select>
         <span className="text-[10px] text-ink-mid">{fileCount} files</span>
       </div>
diff --git a/canvas/src/components/tabs/FilesTab/__tests__/agentHome.test.tsx b/canvas/src/components/tabs/FilesTab/__tests__/agentHome.test.tsx
new file mode 100644
index 000000000..0bb4005de
--- /dev/null
+++ b/canvas/src/components/tabs/FilesTab/__tests__/agentHome.test.tsx
@@ -0,0 +1,181 @@
+// @vitest-environment jsdom
+/**
+ * Tests for the /agent-home root selector + per-runtime default-root
+ * + secret-shape denial placeholder (internal#425 Phase 3).
+ *
+ * Separate file so the diff is reviewable as a unit and the existing
+ * FilesToolbar / FileEditor / FilesTab tests don't have to grow
+ * agent-home-specific cases. Once Phase 2b lands, the read-only +
+ * 501-stub assertions here can be tightened (or moved into the main
+ * test file as the agent-home root becomes a first-class affordance).
+ */
+import React from "react";
+import { render, screen, cleanup } from "@testing-library/react";
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+import { FilesToolbar } from "../FilesToolbar";
+import {
+  FileEditor,
+  SECRET_SHAPE_DENIED_MARKER,
+} from "../FileEditor";
+
+afterEach(cleanup);
+
+describe("internal#425 Phase 3 — /agent-home root selector", () => {
+  it("dropdown includes /agent-home as an option", () => {
+    // Pins the affordance is in the DOM even pre-Phase-2b — the
+    // canvas design freezes today, the backend lands the dispatch
+    // later. Without this, a future refactor that drops the option
+    // would silently regress the RFC's Phase 1 contract (canvas
+    // visibility) without breaking any other test.
+    render(
+      <FilesToolbar
+        root="/configs"
+        setRoot={vi.fn()}
+        fileCount={0}
+        onNewFile={vi.fn()}
+        onUpload={vi.fn()}
+        onDownloadAll={vi.fn()}
+        onClearAll={vi.fn()}
+        onRefresh={vi.fn()}
+      />,
+    );
+    const select = screen.getByRole("combobox", {
+      name: /file root directory/i,
+    }) as HTMLSelectElement;
+    const values = Array.from(select.options).map((o) => o.value);
+    expect(values).toContain("/agent-home");
+  });
+
+  it("dropdown shows /agent-home as the SELECTED root when prop is /agent-home", () => {
+    render(
+      <FilesToolbar
+        root="/agent-home"
+        setRoot={vi.fn()}
+        fileCount={0}
+        onNewFile={vi.fn()}
+        onUpload={vi.fn()}
+        onDownloadAll={vi.fn()}
+        onClearAll={vi.fn()}
+        onRefresh={vi.fn()}
+      />,
+    );
+    const select = screen.getByRole("combobox", {
+      name: /file root directory/i,
+    }) as HTMLSelectElement;
+    expect(select.value).toBe("/agent-home");
+  });
+});
+
+describe("internal#425 Phase 3 — secret-shape denial placeholder", () => {
+  // Files API Phase 2b returns SECRET_SHAPE_DENIED_MARKER as the file
+  // body when the file's path or content matched a credential regex.
+  // The editor MUST render the marker as a placeholder, not pump it
+  // through the textarea — that would put the marker (and any future
+  // matched bytes if the backend contract changes) into the DOM
+  // value, clipboard, and inspector.
+
+  it("renders the denial placeholder INSTEAD of the textarea when fileContent is the marker", () => {
+    render(
+      <FileEditor
+        selectedFile="agent/.openclaw/secrets.env"
+        fileContent={SECRET_SHAPE_DENIED_MARKER}
+        editContent={SECRET_SHAPE_DENIED_MARKER}
+        setEditContent={vi.fn()}
+        loadingFile={false}
+        saving={false}
+        success={null}
+        root="/agent-home"
+        onSave={vi.fn()}
+        onDownload={vi.fn()}
+      />,
+    );
+    // Placeholder region present
+    expect(
+      screen.getByRole("region", { name: /file content denied/i }),
+    ).toBeTruthy();
+    // Marker text visible (so a debugging operator sees the canonical
+    // contract string without having to dig into the source).
+    expect(screen.getByText(SECRET_SHAPE_DENIED_MARKER)).toBeTruthy();
+    // Critically: NO textarea — the bytes never reach a controlled
+    // input. A regression that re-introduces the textarea path would
+    // make the matched marker (and any future content) selectable +
+    // copyable.
+    expect(screen.queryByRole("textbox")).toBeNull();
+  });
+
+  it("renders the textarea normally when fileContent is regular content", () => {
+    render(
+      <FileEditor
+        selectedFile="config.yaml"
+        fileContent="name: openclaw\n"
+        editContent="name: openclaw\n"
+        setEditContent={vi.fn()}
+        loadingFile={false}
+        saving={false}
+        success={null}
+        root="/configs"
+        onSave={vi.fn()}
+        onDownload={vi.fn()}
+      />,
+    );
+    expect(screen.getByRole("textbox")).toBeTruthy();
+    expect(screen.queryByRole("region", { name: /file content denied/i }))
+      .toBeNull();
+  });
+
+  it("/agent-home renders textarea READ-ONLY for non-denied content", () => {
+    // Phase 2b ships read + delete on /agent-home; write semantics
+    // are decided later. Until then, the canvas presents the editor
+    // as read-only so a user can't type into a buffer that the
+    // backend will refuse to PUT. Without this gate, the user would
+    // edit, hit Save, get a 501, and lose their context for why.
+    render(
+      <FileEditor
+        selectedFile=".openclaw/agent-card.json"
+        fileContent='{"name":"openclaw"}'
+        editContent='{"name":"openclaw"}'
+        setEditContent={vi.fn()}
+        loadingFile={false}
+        saving={false}
+        success={null}
+        root="/agent-home"
+        onSave={vi.fn()}
+        onDownload={vi.fn()}
+      />,
+    );
+    const textarea = screen.getByRole("textbox") as HTMLTextAreaElement;
+    expect(textarea.readOnly).toBe(true);
+  });
+
+  it("/configs renders textarea WRITABLE (regression guard for the read-only gate)", () => {
+    render(
+      <FileEditor
+        selectedFile="config.yaml"
+        fileContent="name: x\n"
+        editContent="name: x\n"
+        setEditContent={vi.fn()}
+        loadingFile={false}
+        saving={false}
+        success={null}
+        root="/configs"
+        onSave={vi.fn()}
+        onDownload={vi.fn()}
+      />,
+    );
+    const textarea = screen.getByRole("textbox") as HTMLTextAreaElement;
+    expect(textarea.readOnly).toBe(false);
+  });
+});
+
+describe("internal#425 Phase 3 — marker constant is the canonical string", () => {
+  // The marker string is part of the canvas <-> workspace-server
+  // contract. The workspace-server emits this exact body; the canvas
+  // detects it by exact-equality. A typo on either side would
+  // silently break detection — the canvas would render the literal
+  // string in the textarea instead of the placeholder. Pin the
+  // contract value here.
+  it("matches the contract value '<denied: secret-shape>'", () => {
+    expect(SECRET_SHAPE_DENIED_MARKER).toBe("<denied: secret-shape>");
+  });
+});
diff --git a/canvas/src/components/ui/TestConnectionButton.tsx b/canvas/src/components/ui/TestConnectionButton.tsx
index 940c06e49..a85714ef8 100644
--- a/canvas/src/components/ui/TestConnectionButton.tsx
+++ b/canvas/src/components/ui/TestConnectionButton.tsx
@@ -2,7 +2,7 @@
 
 import { useState, useCallback, useRef, useEffect } from 'react';
 import type { TestConnectionState, SecretGroup } from '@/types/secrets';
-import { validateSecret } from '@/lib/api/secrets';
+import { validateSecret, ApiError } from '@/lib/api/secrets';
 
 interface TestConnectionButtonProps {
   provider: SecretGroup;
@@ -55,9 +55,23 @@ export function TestConnectionButton({
       }
       onResult?.(result.valid);
       resetTimerRef.current = setTimeout(() => setState('idle'), RESET_DELAYS[nextState]!);
-    } catch {
+    } catch (err) {
+      // Distinguish a real failure shape rather than always claiming a
+      // timeout. A reachable server that answered with an HTTP status
+      // (ApiError) did NOT time out — most commonly the validation route
+      // is not available (404/501), which must not masquerade as
+      // "service down". Only an actual thrown network/abort error is a
+      // connectivity failure.
       setState('failure');
-      setErrorDetail('Connection timed out. Service may be down.');
+      if (err instanceof ApiError) {
+        setErrorDetail(
+          err.status === 404 || err.status === 501
+            ? 'Key validation is not available for this service yet. The key was not tested.'
+            : `Could not verify key (server returned ${err.status}). Saving is unaffected.`,
+        );
+      } else {
+        setErrorDetail('Could not reach the validation service. Check your connection and try again.');
+      }
       onResult?.(false);
       resetTimerRef.current = setTimeout(() => setState('idle'), RESET_DELAYS.failure);
     }
diff --git a/canvas/src/components/ui/__tests__/TestConnectionButton.test.tsx b/canvas/src/components/ui/__tests__/TestConnectionButton.test.tsx
index 62d61ff11..21114ef1d 100644
--- a/canvas/src/components/ui/__tests__/TestConnectionButton.test.tsx
+++ b/canvas/src/components/ui/__tests__/TestConnectionButton.test.tsx
@@ -28,8 +28,20 @@ const mockValidateSecret = vi.fn();
 
 vi.mock("@/lib/api/secrets", () => ({
   validateSecret: (...args: unknown[]) => mockValidateSecret(...args),
+  ApiError: class ApiError extends Error {
+    status: number;
+    constructor(status: number, message: string) {
+      super(message);
+      this.name = "ApiError";
+      this.status = status;
+    }
+  },
 }));
 
+// Re-import the mocked ApiError so test cases construct the same class the
+// component's `instanceof` check sees.
+import { ApiError } from "@/lib/api/secrets";
+
 beforeEach(() => {
   vi.useFakeTimers();
   vi.clearAllMocks();
@@ -201,8 +213,27 @@ describe("TestConnectionButton — failure path", () => {
 });
 
 describe("TestConnectionButton — catch path", () => {
-  it("shows 'Connection timed out' on network error", async () => {
-    mockValidateSecret.mockRejectedValue(new Error("timeout"));
+  it("does NOT claim a timeout when the validate endpoint 404s (regression: internal#492)", async () => {
+    // The validate route is unimplemented on the server and returns a fast
+    // 404. Before the fix this rendered the misleading hardcoded string
+    // "Connection timed out. Service may be down." It must instead state
+    // honestly that validation isn't available and the key was not tested.
+    mockValidateSecret.mockRejectedValue(new ApiError(404, "Not Found"));
+    render(
+      <TestConnectionButton provider="anthropic" secretValue="sk-ant-xxx" />,
+    );
+    fireEvent.click(document.querySelector('button[type="button"]')!);
+    await act(async () => {
+      await vi.advanceTimersByTimeAsync(0);
+    });
+    expect(document.body.textContent).not.toContain("Connection timed out");
+    expect(document.body.textContent).not.toContain("Service may be down");
+    expect(document.body.textContent).toContain("not available");
+    expect(document.body.textContent).toContain("not tested");
+  });
+
+  it("reports a non-404 server error with its status, not a timeout", async () => {
+    mockValidateSecret.mockRejectedValue(new ApiError(500, "Internal Server Error"));
     render(
       <TestConnectionButton provider="github" secretValue="ghp_xxx" />,
     );
@@ -210,7 +241,20 @@ describe("TestConnectionButton — catch path", () => {
     await act(async () => {
       await vi.advanceTimersByTimeAsync(0);
     });
-    expect(document.body.textContent).toContain("Connection timed out");
+    expect(document.body.textContent).toContain("500");
+    expect(document.body.textContent).not.toContain("Connection timed out");
+  });
+
+  it("shows a connectivity message on a genuine network error", async () => {
+    mockValidateSecret.mockRejectedValue(new Error("network down"));
+    render(
+      <TestConnectionButton provider="github" secretValue="ghp_xxx" />,
+    );
+    fireEvent.click(document.querySelector('button[type="button"]')!);
+    await act(async () => {
+      await vi.advanceTimersByTimeAsync(0);
+    });
+    expect(document.body.textContent).toContain("Could not reach the validation service");
   });
 
   it("calls onResult(false) on network error", async () => {
diff --git a/workspace-server/internal/handlers/a2a_proxy.go b/workspace-server/internal/handlers/a2a_proxy.go
index 8fbef20c6..c06c553fd 100644
--- a/workspace-server/internal/handlers/a2a_proxy.go
+++ b/workspace-server/internal/handlers/a2a_proxy.go
@@ -399,7 +399,21 @@ func (h *WorkspaceHandler) proxyA2ARequest(ctx context.Context, workspaceID stri
 	// (no Do(), no maybeMarkContainerDead). The response is a synthetic
 	// {status:"queued"} envelope so the caller (canvas, another workspace)
 	// knows delivery is acknowledged but pending consumption.
-	if lookupDeliveryMode(ctx, workspaceID) == models.DeliveryModePoll {
+	deliveryMode, deliveryModeErr := lookupDeliveryMode(ctx, workspaceID)
+	if deliveryModeErr != nil {
+		// internal#497 fail-closed: a real DB/context error on the
+		// delivery-mode read MUST NOT silently fall through to the push
+		// dispatch path — that is exactly what silently misrouted every
+		// poll-mode peer for 5 days under the ce2db75f regression. Surface
+		// a structured error so the delegation is marked failed (loud +
+		// retryable) instead of dispatched to the wrong path.
+		log.Printf("ProxyA2A: delivery-mode lookup failed for %s: %v — failing closed", workspaceID, deliveryModeErr)
+		return 0, nil, &proxyA2AError{
+			Status:   http.StatusServiceUnavailable,
+			Response: gin.H{"error": "delivery-mode lookup failed; refusing to dispatch to avoid silent misrouting"},
+		}
+	}
+	if deliveryMode == models.DeliveryModePoll {
 		if logActivity {
 			h.logA2AReceiveQueued(ctx, workspaceID, callerID, body, a2aMethod)
 		}
diff --git a/workspace-server/internal/handlers/a2a_proxy_helpers.go b/workspace-server/internal/handlers/a2a_proxy_helpers.go
index 8145a66a1..08fd21020 100644
--- a/workspace-server/internal/handlers/a2a_proxy_helpers.go
+++ b/workspace-server/internal/handlers/a2a_proxy_helpers.go
@@ -194,6 +194,11 @@ func (h *WorkspaceHandler) maybeMarkContainerDead(ctx context.Context, workspace
 	}
 	db.ClearWorkspaceKeys(ctx, workspaceID)
 	h.broadcaster.RecordAndBroadcast(ctx, string(events.EventWorkspaceOffline), workspaceID, map[string]interface{}{})
+	// Tracked via goAsync (not bare `go`) so the asyncWG can be drained
+	// before a test swaps the global db.DB. runRestartCycle reads db.DB
+	// before its provisioner gate, so an untracked detached goroutine
+	// races setupTestDB's t.Cleanup db.DB restore. Matches the already-
+	// correct site at a2a_proxy.go:648.
 	h.goAsync(func() { h.RestartByID(workspaceID) })
 	return true
 }
@@ -241,6 +246,9 @@ func (h *WorkspaceHandler) preflightContainerHealth(ctx context.Context, workspa
 	}
 	db.ClearWorkspaceKeys(ctx, workspaceID)
 	h.broadcaster.RecordAndBroadcast(ctx, string(events.EventWorkspaceOffline), workspaceID, map[string]interface{}{})
+	// Tracked via goAsync (see maybeMarkContainerDead): preflight's
+	// detached restart must be drainable so it doesn't race the global
+	// db.DB swap in test cleanup.
 	h.goAsync(func() { h.RestartByID(workspaceID) })
 	return &proxyA2AError{
 		Status: http.StatusServiceUnavailable,
@@ -262,8 +270,9 @@ func (h *WorkspaceHandler) logA2AFailure(ctx context.Context, workspaceID, calle
 		errWsName = workspaceID
 	}
 	summary := "A2A request to " + errWsName + " failed: " + errMsg
+	parent := ctx
 	h.goAsync(func() {
-		logCtx, cancel := context.WithTimeout(context.WithoutCancel(ctx), 30*time.Second)
+		logCtx, cancel := context.WithTimeout(context.WithoutCancel(parent), 30*time.Second)
 		defer cancel()
 		LogActivity(logCtx, h.broadcaster, ActivityParams{
 			WorkspaceID:  workspaceID,
@@ -309,8 +318,9 @@ func (h *WorkspaceHandler) logA2ASuccess(ctx context.Context, workspaceID, calle
 	}
 	summary := a2aMethod + " → " + wsNameForLog
 	toolTrace := extractToolTrace(respBody)
+	parent := ctx
 	h.goAsync(func() {
-		logCtx, cancel := context.WithTimeout(context.WithoutCancel(ctx), 30*time.Second)
+		logCtx, cancel := context.WithTimeout(context.WithoutCancel(parent), 30*time.Second)
 		defer cancel()
 		LogActivity(logCtx, h.broadcaster, ActivityParams{
 			WorkspaceID:  workspaceID,
@@ -458,40 +468,64 @@ func parseUsageFromA2AResponse(body []byte) (inputTokens, outputTokens int64) {
 	return 0, 0
 }
 
-// lookupDeliveryMode returns the workspace's delivery_mode. On any DB
-// error or missing row it returns DeliveryModePush — the fail-closed
-// default. "Closed" here means "fall back to today's behavior (synchronous
-// dispatch)" rather than "fall back to drop the request silently into
-// activity_logs where the agent might never see it." A poll-mode workspace
-// that briefly reads as push will get its A2A request dispatched to the
-// stored URL (or a 502 if no URL); a push-mode workspace that briefly
-// reads as poll would get its request silently queued with no dispatch.
-// The first failure is loud + recoverable; the second is silent.
+// lookupDeliveryMode returns the workspace's delivery_mode.
+//
+// internal#497 / RFC#497 fail-closed (SURGICAL scope): the *specific*
+// failure mode that hid the ce2db75f regression for 5 days is now
+// propagated instead of silently swallowed — a CONTEXT error
+// (context.Canceled / context.DeadlineExceeded). Under ce2db75f the
+// detached delegation goroutine ran on a cancelled request context, every
+// `SELECT delivery_mode` failed `context canceled`, this function returned
+// push, the poll-mode short-circuit in proxyA2ARequest was skipped, and
+// poll-mode peers (e.g. an operator laptop on molecule-mcp-claude-channel)
+// silently never got their a2a_receive inbox row. A transient,
+// systematic-once-triggered context cancellation became permanent
+// invisible misrouting. Returning that error lets the caller fail loud
+// (mark the delegation failed) instead of mis-dispatching.
+//
+// Scope is deliberately narrow: only ctx errors propagate. Other DB
+// errors retain the long-standing documented "fall back to push (today's
+// synchronous behavior)" contract — that path is loud + recoverable
+// (502 / SSRF reject / restart), unlike the silent poll-mode drop, and
+// the surrounding proxy (incl. the sibling checkWorkspaceBudget) is
+// intentionally built around that fail-open-to-push behavior. Widening
+// further is an RFC#497 follow-up, not part of this P0 fix.
+//
+// A genuinely *absent* configuration is NOT an error and still resolves to
+// push (the safe synchronous default): sql.ErrNoRows, a NULL/empty column,
+// or an unrecognised value all return (push, nil).
 //
 // The function is intentionally lookup-only — it never mutates the row.
 // The register handler (registry.go) is the only writer for delivery_mode.
 //
 // See #2339 PR 1 for the column + register-flow side; this is the
 // proxy-side read used for the short-circuit in proxyA2ARequest.
-func lookupDeliveryMode(ctx context.Context, workspaceID string) string {
+func lookupDeliveryMode(ctx context.Context, workspaceID string) (string, error) {
 	var mode sql.NullString
 	err := db.DB.QueryRowContext(ctx,
 		`SELECT delivery_mode FROM workspaces WHERE id = $1`, workspaceID,
 	).Scan(&mode)
 	if err != nil {
-		if !errors.Is(err, sql.ErrNoRows) {
-			log.Printf("ProxyA2A: lookupDeliveryMode(%s) failed (%v) — defaulting to push", workspaceID, err)
+		// internal#497: a context cancellation/deadline MUST NOT be
+		// swallowed into a silent push default — that is the exact 5-day
+		// silent-misrouting vector. Propagate so the caller fails closed.
+		if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
+			log.Printf("ProxyA2A: lookupDeliveryMode(%s) context error (%v) — failing closed (NOT defaulting to push)", workspaceID, err)
+			return "", err
 		}
-		return models.DeliveryModePush
+		if !errors.Is(err, sql.ErrNoRows) {
+			log.Printf("ProxyA2A: lookupDeliveryMode(%s) failed (%v) — defaulting to push (non-ctx DB error; legacy fail-open-to-push contract)", workspaceID, err)
+		}
+		return models.DeliveryModePush, nil
 	}
 	if !mode.Valid || mode.String == "" {
-		return models.DeliveryModePush
+		return models.DeliveryModePush, nil
 	}
 	if !models.IsValidDeliveryMode(mode.String) {
 		log.Printf("ProxyA2A: workspace %s has invalid delivery_mode=%q — defaulting to push", workspaceID, mode.String)
-		return models.DeliveryModePush
+		return models.DeliveryModePush, nil
 	}
-	return mode.String
+	return mode.String, nil
 }
 
 // logA2AReceiveQueued records a poll-mode "queued" A2A receive into
diff --git a/workspace-server/internal/handlers/a2a_proxy_test.go b/workspace-server/internal/handlers/a2a_proxy_test.go
index 3cf954624..d2173d4c3 100644
--- a/workspace-server/internal/handlers/a2a_proxy_test.go
+++ b/workspace-server/internal/handlers/a2a_proxy_test.go
@@ -2235,12 +2235,18 @@ func TestProxyA2A_PushMode_NoShortCircuit(t *testing.T) {
 	}
 }
 
-// TestProxyA2A_PollMode_FailsClosedToPush verifies the safety contract:
-// a DB error reading delivery_mode must default to push (the existing
-// behavior), NOT poll. Failing to push means a poll-mode workspace
-// briefly attempts a real dispatch — visible failure (502 / SSRF
-// rejection / restart cascade), not a silent drop into activity_logs
-// where the agent might never look. Loud > silent, recoverable > lost.
+// TestProxyA2A_PollMode_FailsClosedToPush verifies the LEGACY safety
+// contract is PRESERVED for non-context DB errors: a generic DB error
+// reading delivery_mode still defaults to push (today's behavior), NOT
+// poll. Failing to push means a poll-mode workspace briefly attempts a
+// real dispatch — visible failure (502 / SSRF rejection / restart
+// cascade), not a silent drop into activity_logs where the agent might
+// never look. Loud > silent, recoverable > lost.
+//
+// internal#497 narrows the fail-closed change to *context* errors only
+// (the actual ce2db75f regression vector); generic DB errors keep this
+// long-standing fail-open-to-push contract. The ctx-error fail-closed is
+// covered by TestLookupDeliveryMode_ContextCanceled_FailsClosed.
 func TestProxyA2A_PollMode_FailsClosedToPush(t *testing.T) {
 	mock := setupTestDB(t)
 	setupTestRedis(t) // empty Redis — forces resolveAgentURL DB lookup
@@ -2251,7 +2257,8 @@ func TestProxyA2A_PollMode_FailsClosedToPush(t *testing.T) {
 
 	expectBudgetCheck(mock, wsID)
 
-	// lookupDeliveryMode hits a transient DB error → must default push.
+	// lookupDeliveryMode hits a generic (non-context) DB error → must
+	// still default push (legacy contract preserved by internal#497).
 	mock.ExpectQuery("SELECT delivery_mode FROM workspaces WHERE id").
 		WithArgs(wsID).
 		WillReturnError(sql.ErrConnDone)
@@ -2275,7 +2282,7 @@ func TestProxyA2A_PollMode_FailsClosedToPush(t *testing.T) {
 		var resp map[string]interface{}
 		_ = json.Unmarshal(w.Body.Bytes(), &resp)
 		if resp["status"] == "queued" {
-			t.Errorf("DB error on delivery_mode lookup silently queued the request — must fail-closed-to-push, got body: %s", w.Body.String())
+			t.Errorf("generic DB error on delivery_mode lookup silently queued the request — must fail-open-to-push, got body: %s", w.Body.String())
 		}
 	}
 
@@ -2284,6 +2291,37 @@ func TestProxyA2A_PollMode_FailsClosedToPush(t *testing.T) {
 	}
 }
 
+// TestLookupDeliveryMode_ContextCanceled_FailsClosed is the internal#497
+// regression test for the SECONDARY defect. It pins the exact invariant
+// that hid the ce2db75f regression for 5 days: when the delivery_mode read
+// fails because the context was cancelled (precisely what happened in the
+// detached delegation goroutine running on a returned request context),
+// lookupDeliveryMode MUST return an error and MUST NOT silently return
+// "push". Returning push there is what skipped the poll-mode short-circuit
+// and silently dropped 100% of poll-mode peer deliveries.
+//
+// A pre-cancelled context makes QueryRowContext fail with
+// context.Canceled deterministically — no DB rows are mocked because the
+// query never reaches a result.
+func TestLookupDeliveryMode_ContextCanceled_FailsClosed(t *testing.T) {
+	mock := setupTestDB(t)
+	// The query fails on the cancelled ctx before matching; provide a
+	// permissive expectation so sqlmock doesn't complain about the attempt.
+	mock.ExpectQuery("SELECT delivery_mode FROM workspaces WHERE id").
+		WillReturnError(context.Canceled)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel() // simulate the HTTP handler having returned (request ctx dead)
+
+	mode, err := lookupDeliveryMode(ctx, "ws-poll-peer")
+	if err == nil {
+		t.Fatalf("internal#497 regression: lookupDeliveryMode swallowed a context error and returned mode=%q with nil err — this is the exact 5-day silent-misrouting vector", mode)
+	}
+	if mode == models.DeliveryModePush {
+		t.Errorf("internal#497 regression: context error must NOT default to push (got mode=%q)", mode)
+	}
+}
+
 // ==================== a2aClient ResponseHeaderTimeout config ====================
 
 func TestA2AClientResponseHeaderTimeout(t *testing.T) {
diff --git a/workspace-server/internal/handlers/agent_card_reconcile.go b/workspace-server/internal/handlers/agent_card_reconcile.go
new file mode 100644
index 000000000..b5fac314f
--- /dev/null
+++ b/workspace-server/internal/handlers/agent_card_reconcile.go
@@ -0,0 +1,113 @@
+package handlers
+
+import "encoding/json"
+
+// agent_card_reconcile.go — server-side repair for the fleet-wide
+// agent-card identity gap.
+//
+// Root cause: the runtime builds its AgentCard from config.name
+// (workspace/main.py:198), and config.name is read from the
+// CP-regenerated /configs/config.yaml whose `name:` field is the raw
+// workspace UUID — NOT the friendly name the operator sees. The friendly
+// name IS captured: POST /workspaces and PATCH /workspaces/:id (the
+// canvas Details tab) write it to the trusted workspaces.name DB column.
+// But /registry/register stores the runtime-supplied card verbatim
+// (registry.go: `agent_card = EXCLUDED.agent_card`), so the stored card
+// served at /.well-known/agent-card.json and returned to peers via
+// agent_card_url ends up with name = UUID, description = "", role = null.
+//
+// Fix shape (deliberately minimal, no contract weakening): when the
+// runtime-supplied card's `name` is empty or equals the workspace UUID
+// (the placeholder the runtime had no better value for), the PLATFORM —
+// not the agent — substitutes the friendly value from the trusted
+// workspaces row. Identity stays platform-controlled: the agent never
+// gains the ability to self-set its own name/role; the platform sources
+// it from the operator-controlled DB column. We only ever FILL gaps
+// (empty / UUID-placeholder); a card that already carries a real
+// friendly name is never downgraded.
+//
+// list_peers / the /registry/:id/peers endpoint already resolve display
+// names from workspaces.name directly (discovery.go / mcp_tools.go
+// `SELECT w.id, w.name, ...`), so peer_name in delivered message tags
+// was already correct — this fix closes the remaining surface: the
+// agent_card blob itself (canvas Agent Card / Skills view, peer
+// agent_card_url fetches, the well-known card).
+//
+// description / role degrade discovery the same way: an empty
+// description and null role give peers nothing to reason about. We
+// default description from the (now reconciled) name when blank and
+// role from workspaces.role when the operator set one.
+
+// reconcileAgentCardIdentity patches identity gaps in a runtime-supplied
+// agent card from the trusted workspace DB row. It returns the
+// (possibly rewritten) card bytes and whether anything changed. On any
+// failure (malformed JSON, nothing to fill) it returns the input bytes
+// unchanged with changed=false so the caller can store them verbatim —
+// this is strictly no-worse-than-before, never a regression.
+//
+// Pure function: no DB / HTTP / globals, so it is exhaustively
+// unit-testable (agent_card_reconcile_test.go) without booting the
+// handler or a sqlmock.
+func reconcileAgentCardIdentity(card json.RawMessage, workspaceID, dbName, dbRole string) (json.RawMessage, bool) {
+	var m map[string]any
+	if err := json.Unmarshal(card, &m); err != nil || m == nil {
+		// Malformed card — not this function's job to reject it (the
+		// upsert stores it as-is and downstream readers handle bad
+		// JSON). Return verbatim so byte-for-byte behaviour is
+		// preserved on the failure path.
+		return card, false
+	}
+
+	changed := false
+
+	// name: fill only when empty or the UUID placeholder. A dbName that
+	// is itself the UUID is a placeholder row (registry.go INSERT seeds
+	// name = id before the canvas sets a friendly one) — not a friendly
+	// name, so it is not an eligible source.
+	cardName, _ := m["name"].(string)
+	if (cardName == "" || cardName == workspaceID) &&
+		dbName != "" && dbName != workspaceID {
+		m["name"] = dbName
+		changed = true
+	}
+
+	// description: when blank, default to the (reconciled) name so peers
+	// and the canvas Agent Card view have a non-empty human label
+	// instead of "". Mirrors the runtime's own
+	// `config.description or config.name` fallback (main.py:199) but
+	// applied to the registry copy where the runtime's fallback was the
+	// UUID.
+	if desc, _ := m["description"].(string); desc == "" {
+		if n, _ := m["name"].(string); n != "" && n != workspaceID {
+			m["description"] = n
+			changed = true
+		}
+	}
+
+	// role: surface the operator-set workspaces.role when the card
+	// carries none. Discovery (peer_role) and the canvas Role row read
+	// workspaces.role directly; this just makes the standalone card
+	// self-describing too. Never overwrite a role the card already has.
+	if dbRole != "" {
+		if r, ok := m["role"].(string); !ok || r == "" {
+			m["role"] = dbRole
+			changed = true
+		}
+	}
+
+	if !changed {
+		// No-op: return the original bytes untouched so callers that
+		// compare/store get byte-identical input (re-marshalling would
+		// reorder keys for no reason).
+		return card, false
+	}
+
+	out, err := json.Marshal(m)
+	if err != nil {
+		// Re-marshal of a map we just unmarshalled should never fail;
+		// if it somehow does, fall back to the verbatim input rather
+		// than storing nothing.
+		return card, false
+	}
+	return out, true
+}
diff --git a/workspace-server/internal/handlers/agent_card_reconcile_test.go b/workspace-server/internal/handlers/agent_card_reconcile_test.go
new file mode 100644
index 000000000..75d5976b6
--- /dev/null
+++ b/workspace-server/internal/handlers/agent_card_reconcile_test.go
@@ -0,0 +1,166 @@
+package handlers
+
+import (
+	"encoding/json"
+	"testing"
+)
+
+// TestReconcileAgentCardIdentity covers the server-side backfill that
+// repairs the fleet-wide agent-card identity gap (internal#XXX): the
+// runtime POSTs /registry/register with agent_card.name = the workspace
+// UUID (because the CP-regenerated /configs/config.yaml sets name: <uuid>)
+// while the trusted workspaces.name DB column — the value the canvas
+// Details tab shows and lets the operator edit — holds the friendly
+// name ("Claude Code Agent"). The platform reconciles them from the DB
+// row (NOT from the agent — identity stays platform-controlled, not
+// self-mutable).
+func TestReconcileAgentCardIdentity(t *testing.T) {
+	const wsID = "3b81321b-1ec7-488c-96f7-72c42a968da6"
+
+	tests := []struct {
+		name        string
+		card        string
+		dbName      string
+		dbRole      string
+		wantName    string
+		wantDesc    string
+		wantRole    string
+		wantChanged bool
+	}{
+		{
+			name:        "name is the workspace UUID — backfill from DB",
+			card:        `{"name":"3b81321b-1ec7-488c-96f7-72c42a968da6","description":"","capabilities":{"streaming":true}}`,
+			dbName:      "Claude Code Agent",
+			dbRole:      "",
+			wantName:    "Claude Code Agent",
+			wantDesc:    "Claude Code Agent",
+			wantRole:    "",
+			wantChanged: true,
+		},
+		{
+			name:        "empty name — backfill from DB",
+			card:        `{"name":"","description":"x"}`,
+			dbName:      "ops-agent",
+			dbRole:      "sre",
+			wantName:    "ops-agent",
+			wantDesc:    "x",
+			wantRole:    "sre",
+			wantChanged: true,
+		},
+		{
+			name:        "role null in card, DB has role — backfill role only",
+			card:        `{"name":"Reviewer","description":"Senior reviewer"}`,
+			dbName:      "Reviewer",
+			dbRole:      "code-reviewer",
+			wantName:    "Reviewer",
+			wantDesc:    "Senior reviewer",
+			wantRole:    "code-reviewer",
+			wantChanged: true,
+		},
+		{
+			name: "card already has a real friendly name — do NOT clobber it",
+			// A richer card (e.g. an external channel agent) must win;
+			// the platform only fills gaps, never downgrades.
+			card:        `{"name":"Claude Code (channel)","description":"Local Claude Code session bridged","role":"assistant"}`,
+			dbName:      "hongming-pc",
+			dbRole:      "operator",
+			wantName:    "Claude Code (channel)",
+			wantDesc:    "Local Claude Code session bridged",
+			wantRole:    "assistant",
+			wantChanged: false,
+		},
+		{
+			name:        "no DB name available — leave UUID name untouched (no worse than before)",
+			card:        `{"name":"3b81321b-1ec7-488c-96f7-72c42a968da6","description":""}`,
+			dbName:      "",
+			dbRole:      "",
+			wantName:    "3b81321b-1ec7-488c-96f7-72c42a968da6",
+			wantDesc:    "",
+			wantRole:    "",
+			wantChanged: false,
+		},
+		{
+			name:        "dbName equals UUID (placeholder row) — not a friendly name, leave untouched",
+			card:        `{"name":"3b81321b-1ec7-488c-96f7-72c42a968da6"}`,
+			dbName:      "3b81321b-1ec7-488c-96f7-72c42a968da6",
+			dbRole:      "",
+			wantName:    "3b81321b-1ec7-488c-96f7-72c42a968da6",
+			wantDesc:    "",
+			wantRole:    "",
+			wantChanged: false,
+		},
+		{
+			name:        "malformed card JSON — return unchanged, no panic",
+			card:        `{not json`,
+			dbName:      "Claude Code Agent",
+			dbRole:      "",
+			wantChanged: false,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			out, changed := reconcileAgentCardIdentity(
+				json.RawMessage(tc.card), wsID, tc.dbName, tc.dbRole,
+			)
+			if changed != tc.wantChanged {
+				t.Fatalf("changed = %v, want %v", changed, tc.wantChanged)
+			}
+			if !tc.wantChanged {
+				// Unchanged path must return the input bytes verbatim.
+				if string(out) != tc.card {
+					t.Fatalf("unchanged path mutated bytes:\n got  %s\n want %s", out, tc.card)
+				}
+				return
+			}
+			var got map[string]any
+			if err := json.Unmarshal(out, &got); err != nil {
+				t.Fatalf("output not valid JSON: %v (%s)", err, out)
+			}
+			if g, _ := got["name"].(string); g != tc.wantName {
+				t.Errorf("name = %q, want %q", g, tc.wantName)
+			}
+			if g, _ := got["description"].(string); g != tc.wantDesc {
+				t.Errorf("description = %q, want %q", g, tc.wantDesc)
+			}
+			if tc.wantRole != "" {
+				if g, _ := got["role"].(string); g != tc.wantRole {
+					t.Errorf("role = %q, want %q", g, tc.wantRole)
+				}
+			}
+		})
+	}
+}
+
+// TestReconcileAgentCardIdentity_PreservesOtherFields ensures the
+// reconcile is a minimal in-place patch — capabilities, version,
+// skills and any unknown future fields survive untouched.
+func TestReconcileAgentCardIdentity_PreservesOtherFields(t *testing.T) {
+	card := `{"name":"ws-uuid","description":"","version":"1.0.0",` +
+		`"capabilities":{"streaming":true,"pushNotifications":true},` +
+		`"skills":[{"id":"a","name":"a"}],"configuration_status":"ready"}`
+	out, changed := reconcileAgentCardIdentity(
+		json.RawMessage(card), "ws-uuid", "Friendly Name", "",
+	)
+	if !changed {
+		t.Fatal("expected changed = true")
+	}
+	var got map[string]any
+	if err := json.Unmarshal(out, &got); err != nil {
+		t.Fatalf("invalid JSON: %v", err)
+	}
+	if got["version"] != "1.0.0" {
+		t.Errorf("version not preserved: %v", got["version"])
+	}
+	if got["configuration_status"] != "ready" {
+		t.Errorf("configuration_status not preserved: %v", got["configuration_status"])
+	}
+	caps, ok := got["capabilities"].(map[string]any)
+	if !ok || caps["streaming"] != true {
+		t.Errorf("capabilities not preserved: %v", got["capabilities"])
+	}
+	skills, ok := got["skills"].([]any)
+	if !ok || len(skills) != 1 {
+		t.Errorf("skills not preserved: %v", got["skills"])
+	}
+}
diff --git a/workspace-server/internal/handlers/delegation.go b/workspace-server/internal/handlers/delegation.go
index beaa88cf5..3d1b6e5db 100644
--- a/workspace-server/internal/handlers/delegation.go
+++ b/workspace-server/internal/handlers/delegation.go
@@ -163,8 +163,32 @@ func (h *DelegationHandler) Delegate(c *gin.Context) {
 		},
 	})
 
-	// Fire-and-forget: send A2A in background goroutine
-	go h.executeDelegation(ctx, sourceID, body.TargetID, delegationID, a2aBody)
+	// Fire-and-forget: send A2A in a background goroutine.
+	//
+	// internal#497 — the goroutine MUST NOT inherit the HTTP request's
+	// cancellation. `ctx` here is c.Request.Context(); the handler returns
+	// 202 a few lines below, which cancels that context immediately. Before
+	// this fix (regression ce2db75f) executeDelegation ran on the
+	// request-scoped ctx, so every DB op + proxy call in the detached
+	// goroutine failed `context canceled` the instant the 202 was written.
+	// That silently broke 100% of A2A peer delegations fleet-wide since
+	// 2026-05-12 (poll-mode peers never got their a2a_receive inbox row;
+	// lookupDeliveryMode swallowed the ctx error and defaulted to push).
+	//
+	// context.WithoutCancel detaches cancellation/deadline while PRESERVING
+	// all context values (trace/correlation/tenant ids that proxyA2ARequest
+	// and the broadcaster read off ctx) — this is the established pattern in
+	// this package (a2a_proxy.go:850, a2a_proxy_helpers.go:525,
+	// registry.go:822). The 30-minute ceiling matches the prior internal
+	// budget executeDelegation used before ce2db75f and the proxy's own
+	// absolute agent-dispatch ceiling (a2a_proxy.go forwardCtx).
+	delegationCtx, cancelDelegation := context.WithTimeout(
+		context.WithoutCancel(ctx), 30*time.Minute,
+	)
+	go func() {
+		defer cancelDelegation()
+		h.executeDelegation(delegationCtx, sourceID, body.TargetID, delegationID, a2aBody)
+	}()
 
 	// Broadcast event so canvas shows delegation in real-time
 	h.broadcaster.RecordAndBroadcast(ctx, string(events.EventDelegationSent), sourceID, map[string]interface{}{
diff --git a/workspace-server/internal/handlers/delegation_test.go b/workspace-server/internal/handlers/delegation_test.go
index fcd17eec8..223b8de77 100644
--- a/workspace-server/internal/handlers/delegation_test.go
+++ b/workspace-server/internal/handlers/delegation_test.go
@@ -16,6 +16,65 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
+// ---------- internal#497 regression: detached goroutine ctx must outlive the handler ----------
+
+// TestDelegate_DetachedContext_SurvivesRequestCancellation pins the
+// load-bearing invariant that regression ce2db75f violated: the context
+// handed to executeDelegation in the fire-and-forget goroutine must NOT be
+// cancelled when the HTTP handler returns 202 (which cancels
+// c.Request.Context()). Before the fix, executeDelegation ran on the
+// request-scoped ctx, so every DB op + proxy call failed `context
+// canceled` the instant the 202 was written — silently breaking 100% of
+// A2A peer delegations fleet-wide since 2026-05-12.
+//
+// This test asserts the exact ctx-derivation contract used by Delegate
+// (context.WithoutCancel(parent) + a timeout budget): the derived context
+// (a) stays alive after the parent is cancelled, and (b) still carries
+// parent values (trace/correlation/tenant ids the downstream proxy +
+// broadcaster read off ctx). It is intentionally DB-free and fast.
+func TestDelegate_DetachedContext_SurvivesRequestCancellation(t *testing.T) {
+	type ctxKey string
+	const traceKey ctxKey = "trace-id"
+
+	// Simulate c.Request.Context() carrying a correlation value.
+	parent, cancelParent := context.WithCancel(
+		context.WithValue(context.Background(), traceKey, "trace-abc-123"),
+	)
+
+	// Exact derivation Delegate uses for the detached goroutine.
+	delegationCtx, cancelDelegation := context.WithTimeout(
+		context.WithoutCancel(parent), 30*time.Minute,
+	)
+	defer cancelDelegation()
+
+	// The HTTP handler "returns 202" → request context is cancelled.
+	cancelParent()
+
+	if err := parent.Err(); err == nil {
+		t.Fatal("precondition: parent context should be cancelled after the handler returns")
+	}
+
+	// (a) Cancellation MUST NOT propagate to the detached context.
+	select {
+	case <-delegationCtx.Done():
+		t.Fatalf("regression: detached delegation ctx was cancelled by the handler returning (err=%v) — executeDelegation would fail every DB op with `context canceled`", delegationCtx.Err())
+	default:
+		// alive — correct
+	}
+
+	// (b) Parent values MUST still be readable (WithoutCancel preserves
+	// values; trace/correlation/tenant ids the proxy + broadcaster use).
+	if got, _ := delegationCtx.Value(traceKey).(string); got != "trace-abc-123" {
+		t.Errorf("detached ctx lost the parent trace value: got %q, want %q", got, "trace-abc-123")
+	}
+
+	// And it still has a real deadline (the 30m budget), so it is not an
+	// unbounded background context.
+	if _, hasDeadline := delegationCtx.Deadline(); !hasDeadline {
+		t.Error("detached ctx must carry the 30-minute timeout budget, but has no deadline")
+	}
+}
+
 // ---------- Delegate: missing target_id → 400 ----------
 
 func TestDelegate_MissingTargetID(t *testing.T) {
diff --git a/workspace-server/internal/handlers/handlers_test.go b/workspace-server/internal/handlers/handlers_test.go
index 33a039a1c..35323ec29 100644
--- a/workspace-server/internal/handlers/handlers_test.go
+++ b/workspace-server/internal/handlers/handlers_test.go
@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/http/httptest"
+	"sync"
 	"testing"
 	"time"
 
@@ -22,8 +23,39 @@ import (
 	"github.com/redis/go-redis/v9"
 )
 
+// liveTestHandlers tracks every WorkspaceHandler built during the test
+// binary's lifetime so setupTestDB can drain their in-flight goAsync
+// goroutines (notably the detached RestartByID restart cycle, which
+// reads the global db.DB) BEFORE restoring db.DB. Without this drain a
+// fire-and-forget restart goroutine spawned by one test outlives that
+// test and races the db.DB swap in a later test's t.Cleanup — the
+// 0x...d548 data race on platform/internal/db.DB.
+var (
+	liveTestHandlersMu sync.Mutex
+	liveTestHandlers   []*WorkspaceHandler
+)
+
 func init() {
 	gin.SetMode(gin.TestMode)
+	newHandlerHook = func(h *WorkspaceHandler) {
+		liveTestHandlersMu.Lock()
+		liveTestHandlers = append(liveTestHandlers, h)
+		liveTestHandlersMu.Unlock()
+	}
+}
+
+// drainTestAsync waits for every tracked handler's goAsync goroutines to
+// finish. Called from setupTestDB's cleanup before db.DB is restored so
+// no detached restart/provision goroutine is mid-read of db.DB when the
+// pointer is swapped.
+func drainTestAsync() {
+	liveTestHandlersMu.Lock()
+	handlers := make([]*WorkspaceHandler, len(liveTestHandlers))
+	copy(handlers, liveTestHandlers)
+	liveTestHandlersMu.Unlock()
+	for _, h := range handlers {
+		h.waitAsyncForTest()
+	}
 }
 
 // setupTestDB creates a sqlmock DB and assigns it to the global db.DB.
@@ -42,7 +74,16 @@ func setupTestDB(t *testing.T) sqlmock.Sqlmock {
 	}
 	prevDB := db.DB
 	db.DB = mockDB
-	t.Cleanup(func() { db.DB = prevDB; mockDB.Close() })
+	t.Cleanup(func() {
+		// Drain detached async goroutines (e.g. goAsync(RestartByID),
+		// which reads db.DB in runRestartCycle before its provisioner
+		// gate) BEFORE swapping db.DB back. Doing the restore first
+		// would let an in-flight restart goroutine read db.DB while
+		// this line writes it — the data race this guards against.
+		drainTestAsync()
+		db.DB = prevDB
+		mockDB.Close()
+	})
 
 	// Disable SSRF checks for the duration of this test only. Restore
 	// the previous state via t.Cleanup so that TestIsSafeURL_* tests
diff --git a/workspace-server/internal/handlers/registry.go b/workspace-server/internal/handlers/registry.go
index 65a853058..48b9c9285 100644
--- a/workspace-server/internal/handlers/registry.go
+++ b/workspace-server/internal/handlers/registry.go
@@ -327,7 +327,33 @@ func (h *RegistryHandler) Register(c *gin.Context) {
 		}
 	}
 
-	agentCardStr := string(payload.AgentCard)
+	// Reconcile the runtime-supplied card's identity fields against the
+	// trusted workspaces row before storing. The runtime builds its card
+	// from config.name, which the CP-regenerated /configs/config.yaml
+	// sets to the workspace UUID — so without this the stored card
+	// served at /.well-known/agent-card.json and returned to peers via
+	// agent_card_url has name = UUID, description = "", role = null even
+	// though the operator-controlled workspaces.name holds the friendly
+	// name the canvas shows. We only FILL gaps from the DB (never
+	// downgrade a card that already carries a real name); identity stays
+	// platform-controlled — the agent cannot self-set these. Best-effort:
+	// a lookup failure leaves the card exactly as the runtime sent it
+	// (no-worse-than-before). See agent_card_reconcile.go.
+	reconciledCard := payload.AgentCard
+	{
+		var dbName, dbRole sql.NullString
+		if qErr := db.DB.QueryRowContext(ctx,
+			`SELECT name, role FROM workspaces WHERE id = $1`, payload.ID,
+		).Scan(&dbName, &dbRole); qErr == nil {
+			if rc, did := reconcileAgentCardIdentity(
+				payload.AgentCard, payload.ID, dbName.String, dbRole.String,
+			); did {
+				reconciledCard = rc
+				log.Printf("Registry register: reconciled agent_card identity for %s from workspaces row", payload.ID)
+			}
+		}
+	}
+	agentCardStr := string(reconciledCard)
 
 	// urlForUpsert: poll-mode workspaces don't need a URL. Empty input
 	// becomes NULL via sql.NullString so the row's URL stays clean (the
@@ -413,10 +439,12 @@ func (h *RegistryHandler) Register(c *gin.Context) {
 		}
 	}
 
-	// Broadcast WORKSPACE_ONLINE
+	// Broadcast WORKSPACE_ONLINE — use the reconciled card so the canvas
+	// Agent Card view live-updates with the friendly name, matching what
+	// was just persisted (not the runtime's raw UUID-name card).
 	if err := h.broadcaster.RecordAndBroadcast(ctx, string(events.EventWorkspaceOnline), payload.ID, map[string]interface{}{
 		"url":           cachedURL,
-		"agent_card":    payload.AgentCard,
+		"agent_card":    reconciledCard,
 		"delivery_mode": effectiveMode,
 	}); err != nil {
 		log.Printf("Registry broadcast error: %v", err)
diff --git a/workspace-server/internal/handlers/restart_signals.go b/workspace-server/internal/handlers/restart_signals.go
index 7c4c900ac..88ff480a3 100644
--- a/workspace-server/internal/handlers/restart_signals.go
+++ b/workspace-server/internal/handlers/restart_signals.go
@@ -56,8 +56,10 @@ const (
 // (an externally routable address) is used directly.
 func (h *WorkspaceHandler) gracefulPreRestart(ctx context.Context, workspaceID string) {
 	// Non-blocking send — don't stall the restart cycle.
-	// Run in a detached goroutine so the caller (runRestartCycle) can
-	// proceed to stopForRestart without waiting.
+	// Run in a tracked async goroutine (goAsync, not bare `go`) so the
+	// caller (runRestartCycle) can proceed to stopForRestart without
+	// waiting, while the test harness can still drain it before swapping
+	// the global db.DB (resolveAgentURLForRestartSignal reads db.DB).
 	h.goAsync(func() {
 		signalCtx, cancel := context.WithTimeout(context.Background(), restartSignalTimeout)
 		defer cancel()
diff --git a/workspace-server/internal/handlers/template_files_agent_home_stub_test.go b/workspace-server/internal/handlers/template_files_agent_home_stub_test.go
new file mode 100644
index 000000000..2609cc78c
--- /dev/null
+++ b/workspace-server/internal/handlers/template_files_agent_home_stub_test.go
@@ -0,0 +1,117 @@
+package handlers
+
+// template_files_agent_home_stub_test.go — pins the Phase-1 stub
+// contract for the /agent-home root added by internal#425 RFC.
+//
+// Today (pre-Phase-2b), every Files API verb against `?root=/agent-home`
+// must return HTTP 501 with the canonical pending-message body. The
+// stub MUST NOT:
+//   1. Hit the DB (the workspace might not even exist yet from the
+//      canvas's POV — the root selector is testable without one).
+//   2. Touch the EIC tunnel / Docker / template-dir paths — those
+//      would 500/404/[] depending on the env and confuse the canvas.
+//   3. Accept writes/deletes that the future docker-exec backend
+//      would reject — fail closed.
+//
+// When Phase 2b lands, this file gets replaced by a real
+// docker-exec dispatch test; the stub-message constant in
+// templates.go disappears.
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+)
+
+// TestAgentHomeAllowedRoot pins that /agent-home is in the allowedRoots
+// set. Without this, a future refactor that drops the key would
+// silently degrade the canvas root selector to a 400 instead of the
+// stub 501.
+func TestAgentHomeAllowedRoot(t *testing.T) {
+	if !allowedRoots["/agent-home"] {
+		t.Fatal("/agent-home must be in allowedRoots — RFC #425 contract")
+	}
+}
+
+// TestAgentHomeStub_AllVerbs_Return501 pins the canonical stub
+// response across all four verbs. Each must:
+//
+//   - status 501
+//   - body contains the canonical "/agent-home not implemented" prefix
+//   - NOT contain "workspace not found" (proves we short-circuit before
+//     the DB lookup)
+//
+// Driven as a table to keep symmetry — adding a fifth verb in the
+// future means adding one row here.
+func TestAgentHomeStub_AllVerbs_Return501(t *testing.T) {
+	cases := []struct {
+		name   string
+		method string
+		invoke func(c *gin.Context)
+	}{
+		{
+			name:   "ListFiles",
+			method: "GET",
+			invoke: func(c *gin.Context) { (&TemplatesHandler{}).ListFiles(c) },
+		},
+		{
+			name:   "ReadFile",
+			method: "GET",
+			invoke: func(c *gin.Context) { (&TemplatesHandler{}).ReadFile(c) },
+		},
+		{
+			name:   "WriteFile",
+			method: "PUT",
+			invoke: func(c *gin.Context) { (&TemplatesHandler{}).WriteFile(c) },
+		},
+		{
+			name:   "DeleteFile",
+			method: "DELETE",
+			invoke: func(c *gin.Context) { (&TemplatesHandler{}).DeleteFile(c) },
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			w := httptest.NewRecorder()
+			c, _ := gin.CreateTestContext(w)
+			c.Params = gin.Params{
+				{Key: "id", Value: "ws-stub"},
+				// Path param without leading slash so DeleteFile's
+				// filepath.IsAbs guard doesn't 400 before the root
+				// dispatch runs. The List/Read/Write paths strip the
+				// leading slash themselves and accept either form.
+				{Key: "path", Value: "notes.md"},
+			}
+			// WriteFile binds JSON; provide a minimal valid body so the
+			// short-circuit isn't masked by the bind-error path.
+			var body string
+			if tc.method == "PUT" {
+				body = `{"content":"x"}`
+			}
+			c.Request = httptest.NewRequest(
+				tc.method,
+				"/workspaces/ws-stub/files/notes.md?root=/agent-home",
+				strings.NewReader(body),
+			)
+			if body != "" {
+				c.Request.Header.Set("Content-Type", "application/json")
+			}
+
+			tc.invoke(c)
+
+			if w.Code != http.StatusNotImplemented {
+				t.Fatalf("expected 501, got %d: %s", w.Code, w.Body.String())
+			}
+			if !strings.Contains(w.Body.String(), "/agent-home not implemented") {
+				t.Errorf("body should contain canonical stub message; got %s", w.Body.String())
+			}
+			if strings.Contains(w.Body.String(), "workspace not found") {
+				t.Errorf("stub leaked through to DB lookup; body=%s", w.Body.String())
+			}
+		})
+	}
+}
diff --git a/workspace-server/internal/handlers/template_files_eic.go b/workspace-server/internal/handlers/template_files_eic.go
index 87a90b104..8ef8028d1 100644
--- a/workspace-server/internal/handlers/template_files_eic.go
+++ b/workspace-server/internal/handlers/template_files_eic.go
@@ -19,6 +19,7 @@ package handlers
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"log"
 	"os"
@@ -357,6 +358,28 @@ func writeFileViaEIC(ctx context.Context, instanceID, runtime, root, relPath str
 		var stderr bytes.Buffer
 		sshCmd.Stderr = &stderr
 		if err := sshCmd.Run(); err != nil {
+			// When the per-op context deadline (eicFileOpTimeout) fires,
+			// exec.CommandContext SIGKILLs the ssh subprocess and Run()
+			// returns the bare "signal: killed" with empty stderr. That
+			// surfaced to the canvas as an opaque
+			// `500 {"error":"ssh install: signal: killed ()"}` which gave
+			// the operator no idea the workspace was simply mid-provision
+			// with a slow/unready EIC tunnel (internal#423). Detect the
+			// deadline explicitly and return an actionable message instead
+			// — the EIC mechanism, timeout value, and success path are all
+			// unchanged; this only improves the error a stuck write emits.
+			if cerr := ctx.Err(); cerr != nil {
+				reason := "timed out after " + eicFileOpTimeout.String()
+				if errors.Is(cerr, context.Canceled) && !errors.Is(cerr, context.DeadlineExceeded) {
+					reason = "was cancelled"
+				}
+				return fmt.Errorf(
+					"ssh install: EIC tunnel to workspace %s — "+
+						"the workspace may still be provisioning (slow/unready SSH); "+
+						"retry once it is online, or apply provider credentials via "+
+						"Settings → Secrets (encrypted, does not use this file-write path)",
+					reason)
+			}
 			return fmt.Errorf("ssh install: %w (%s)", err, strings.TrimSpace(stderr.String()))
 		}
 		log.Printf("writeFileViaEIC: ws instance=%s runtime=%s root=%s wrote %d bytes → %s",
diff --git a/workspace-server/internal/handlers/template_files_eic_write_timeout_test.go b/workspace-server/internal/handlers/template_files_eic_write_timeout_test.go
new file mode 100644
index 000000000..edef99479
--- /dev/null
+++ b/workspace-server/internal/handlers/template_files_eic_write_timeout_test.go
@@ -0,0 +1,71 @@
+package handlers
+
+// template_files_eic_write_timeout_test.go — pins the actionable-error
+// behavior added for internal#423.
+//
+// When the per-op context deadline (eicFileOpTimeout) fires,
+// exec.CommandContext SIGKILLs the ssh subprocess and Run() returns the
+// bare "signal: killed" with empty stderr. Before the fix that surfaced
+// to the canvas as an opaque `500 {"error":"ssh install: signal:
+// killed ()"}` — useless to an operator whose workspace was simply
+// mid-provision with a slow/unready EIC tunnel. The fix detects the
+// deadline explicitly (errors.Is(ctx.Err(), context.DeadlineExceeded))
+// and returns a message that names the cause and the
+// Settings → Secrets workaround.
+
+import (
+	"context"
+	"strings"
+	"testing"
+	"time"
+)
+
+// TestWriteFileViaEIC_DeadlineExceeded_ActionableError stubs
+// withEICTunnel so the *real* inner closure runs against a context that
+// has already exceeded its deadline. The ssh subprocess fails (no real
+// sshd on the fake port) and ctx.Err() == DeadlineExceeded, so the new
+// branch must fire and produce an actionable message — NOT the opaque
+// "signal: killed ()" string the canvas used to show.
+func TestWriteFileViaEIC_DeadlineExceeded_ActionableError(t *testing.T) {
+	prev := withEICTunnel
+	withEICTunnel = func(_ context.Context, instanceID string, fn func(s eicSSHSession) error) error {
+		// Run the real inner closure. It closes over the ctx that
+		// writeFileViaEIC derived from our already-cancelled parent, so
+		// the ssh subprocess is killed immediately and ctx.Err()
+		// resolves — exactly the eicFileOpTimeout-expiry shape.
+		return fn(eicSSHSession{
+			instanceID: instanceID,
+			osUser:     "ubuntu",
+			localPort:  1, // nothing listening → ssh fails fast
+			keyPath:    "/nonexistent/key",
+		})
+	}
+	t.Cleanup(func() { withEICTunnel = prev })
+
+	// Drive the real writeFileViaEIC. Pass a parent whose deadline has
+	// already passed: the context.WithTimeout(ctx, eicFileOpTimeout)
+	// derived inside writeFileViaEIC inherits the expired parent
+	// deadline, so ctx.Err() == context.DeadlineExceeded by the time
+	// the killed ssh subprocess returns — the exact production shape
+	// (eicFileOpTimeout expiry), exercised deterministically.
+	parent, cancel := context.WithDeadline(context.Background(), time.Now().Add(-time.Second))
+	defer cancel()
+
+	err := writeFileViaEIC(parent, "i-test", "claude-code", "/configs", "config.yaml", []byte("model: sonnet\n"))
+	if err == nil {
+		t.Fatalf("expected an error from a killed ssh subprocess, got nil")
+	}
+	msg := err.Error()
+
+	// Must NOT leak the opaque bare-signal string to the operator.
+	if strings.Contains(msg, "signal: killed ()") {
+		t.Fatalf("error still surfaces the opaque %q form: %q", "signal: killed ()", msg)
+	}
+	// Must name the cause and the Secrets workaround so the canvas
+	// shows something actionable.
+	for _, want := range []string{"timed out", "provisioning", "Settings", "Secrets"} {
+		if !strings.Contains(msg, want) {
+			t.Errorf("actionable error missing %q; got: %q", want, msg)
+		}
+	}
+}
diff --git a/workspace-server/internal/handlers/templates.go b/workspace-server/internal/handlers/templates.go
index 3f41dbb4d..0258419f7 100644
--- a/workspace-server/internal/handlers/templates.go
+++ b/workspace-server/internal/handlers/templates.go
@@ -18,11 +18,35 @@ import (
 )
 
 // allowedRoots are the container paths that the Files API can browse.
+//
+// `/agent-home` (added 2026-05-15, internal#425 RFC) is the container's
+// own $HOME — `/root` for openclaw, `/home/agent` for claude-code/hermes
+// — browsed via `docker exec` rather than host-side `find`. The
+// dispatch is stubbed today (returns 501); full implementation lands in
+// Phase 2b of the RFC. The allowedRoots key is added now so the canvas
+// can design its root-selector UI against the final shape and the
+// stub-vs-full transition is server-side only.
 var allowedRoots = map[string]bool{
-	"/configs":   true,
-	"/workspace": true,
-	"/home":      true,
-	"/plugins":   true,
+	"/configs":    true,
+	"/workspace":  true,
+	"/home":       true,
+	"/plugins":    true,
+	"/agent-home": true,
+}
+
+// agentHomeStubMessage is the body returned by every Files API verb
+// when `?root=/agent-home` is requested before Phase 2b lands. Keep the
+// status code 501 (Not Implemented) — the route exists, the verb is
+// understood, but the handler is unimplemented. Distinguishes from
+// 400/404 so a canvas behind a less-current server can render a clean
+// "feature pending" state instead of a generic error.
+const agentHomeStubMessage = "/agent-home not implemented yet (internal#425 RFC Phase 2b — docker-exec backend pending)"
+
+// isAgentHomeStubRequest returns true when the request targets the
+// stubbed /agent-home root. Centralised so every verb in this file
+// short-circuits with the same response shape.
+func isAgentHomeStubRequest(rootPath string) bool {
+	return rootPath == "/agent-home"
 }
 
 // maxUploadFiles limits the number of files in a single import/replace.
@@ -224,7 +248,14 @@ func (h *TemplatesHandler) ListFiles(c *gin.Context) {
 	//   ?depth= — max depth to recurse (default: 1, max: 5)
 	rootPath := c.DefaultQuery("root", "/configs")
 	if !allowedRoots[rootPath] {
-		c.JSON(http.StatusBadRequest, gin.H{"error": "root must be one of: /configs, /workspace, /home, /plugins"})
+		c.JSON(http.StatusBadRequest, gin.H{"error": "root must be one of: /configs, /workspace, /home, /plugins, /agent-home"})
+		return
+	}
+	// /agent-home dispatch is stubbed pre-Phase-2b. Short-circuit before
+	// the DB lookup + EIC dance so a canvas exercising the new root key
+	// gets a clean 501 instead of a half-effort response.
+	if isAgentHomeStubRequest(rootPath) {
+		c.JSON(http.StatusNotImplemented, gin.H{"error": agentHomeStubMessage})
 		return
 	}
 	subPath := c.DefaultQuery("path", "")
@@ -393,7 +424,11 @@ func (h *TemplatesHandler) ReadFile(c *gin.Context) {
 	ctx := c.Request.Context()
 	rootPath := c.DefaultQuery("root", "/configs")
 	if !allowedRoots[rootPath] {
-		c.JSON(http.StatusBadRequest, gin.H{"error": "root must be one of: /configs, /workspace, /home, /plugins"})
+		c.JSON(http.StatusBadRequest, gin.H{"error": "root must be one of: /configs, /workspace, /home, /plugins, /agent-home"})
+		return
+	}
+	if isAgentHomeStubRequest(rootPath) {
+		c.JSON(http.StatusNotImplemented, gin.H{"error": agentHomeStubMessage})
 		return
 	}
 
@@ -506,7 +541,11 @@ func (h *TemplatesHandler) WriteFile(c *gin.Context) {
 	ctx := c.Request.Context()
 	rootPath := c.DefaultQuery("root", "/configs")
 	if !allowedRoots[rootPath] {
-		c.JSON(http.StatusBadRequest, gin.H{"error": "root must be one of: /configs, /workspace, /home, /plugins"})
+		c.JSON(http.StatusBadRequest, gin.H{"error": "root must be one of: /configs, /workspace, /home, /plugins, /agent-home"})
+		return
+	}
+	if isAgentHomeStubRequest(rootPath) {
+		c.JSON(http.StatusNotImplemented, gin.H{"error": agentHomeStubMessage})
 		return
 	}
 	var wsName, instanceID, runtime string
@@ -583,7 +622,11 @@ func (h *TemplatesHandler) DeleteFile(c *gin.Context) {
 	ctx := c.Request.Context()
 	rootPath := c.DefaultQuery("root", "/configs")
 	if !allowedRoots[rootPath] {
-		c.JSON(http.StatusBadRequest, gin.H{"error": "root must be one of: /configs, /workspace, /home, /plugins"})
+		c.JSON(http.StatusBadRequest, gin.H{"error": "root must be one of: /configs, /workspace, /home, /plugins, /agent-home"})
+		return
+	}
+	if isAgentHomeStubRequest(rootPath) {
+		c.JSON(http.StatusNotImplemented, gin.H{"error": agentHomeStubMessage})
 		return
 	}
 	var wsName, instanceID, runtime string
diff --git a/workspace-server/internal/handlers/tokens.go b/workspace-server/internal/handlers/tokens.go
index c41f8c518..4ce7be815 100644
--- a/workspace-server/internal/handlers/tokens.go
+++ b/workspace-server/internal/handlers/tokens.go
@@ -10,8 +10,20 @@ import (
 	"github.com/Molecule-AI/molecule-monorepo/platform/internal/db"
 	"github.com/Molecule-AI/molecule-monorepo/platform/internal/wsauth"
 	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
 )
 
+// validWorkspaceID returns true when id is a syntactically valid UUID.
+// workspace_id is a `uuid` column; passing a non-UUID (e.g. the canvas
+// "global" sentinel sent when no node is selected) makes Postgres raise
+// `invalid input syntax for type uuid`, which previously leaked as an
+// opaque 500. Reject up front with a clean 400 instead. Mirrors the
+// uuid.Parse guard already used in handlers/activity.go.
+func validWorkspaceID(id string) bool {
+	_, err := uuid.Parse(id)
+	return err == nil
+}
+
 // TokenHandler exposes user-facing token management for workspaces.
 // Routes: GET/POST/DELETE /workspaces/:id/tokens (behind WorkspaceAuth).
 type TokenHandler struct{}
@@ -31,6 +43,10 @@ type tokenListItem struct {
 // never the plaintext or hash).
 func (h *TokenHandler) List(c *gin.Context) {
 	workspaceID := c.Param("id")
+	if !validWorkspaceID(workspaceID) {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid workspace id"})
+		return
+	}
 
 	limit := 50
 	if v := c.Query("limit"); v != "" {
@@ -53,6 +69,7 @@ func (h *TokenHandler) List(c *gin.Context) {
 		LIMIT $2 OFFSET $3
 	`, workspaceID, limit, offset)
 	if err != nil {
+		log.Printf("tokens: list query failed for workspace %s: %v", workspaceID, err)
 		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to list tokens"})
 		return
 	}
@@ -85,6 +102,10 @@ const maxTokensPerWorkspace = 50
 // exactly once in the response — it cannot be recovered afterwards.
 func (h *TokenHandler) Create(c *gin.Context) {
 	workspaceID := c.Param("id")
+	if !validWorkspaceID(workspaceID) {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid workspace id"})
+		return
+	}
 
 	// Rate limit: max active tokens per workspace
 	var count int
@@ -117,6 +138,10 @@ func (h *TokenHandler) Create(c *gin.Context) {
 func (h *TokenHandler) Revoke(c *gin.Context) {
 	workspaceID := c.Param("id")
 	tokenID := c.Param("tokenId")
+	if !validWorkspaceID(workspaceID) {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid workspace id"})
+		return
+	}
 
 	result, err := db.DB.ExecContext(c.Request.Context(), `
 		UPDATE workspace_auth_tokens
diff --git a/workspace-server/internal/handlers/tokens_sqlmock_test.go b/workspace-server/internal/handlers/tokens_sqlmock_test.go
index b0166293e..b3a2d9a52 100644
--- a/workspace-server/internal/handlers/tokens_sqlmock_test.go
+++ b/workspace-server/internal/handlers/tokens_sqlmock_test.go
@@ -41,6 +41,15 @@ import (
 
 func init() { gin.SetMode(gin.TestMode) }
 
+// Workspace IDs are validated as UUIDs up front (tokens.go validWorkspaceID),
+// so handler tests must pass syntactically valid UUIDs. Fixed values keep
+// sqlmock WithArgs assertions deterministic.
+const (
+	wsUUID1 = "11111111-1111-1111-1111-111111111111"
+	wsUUID2 = "22222222-2222-2222-2222-222222222222"
+	wsUUID3 = "33333333-3333-3333-3333-333333333333"
+)
+
 // withMockDB swaps `db.DB` for a sqlmock and returns the mock plus a
 // restore func. Tests use this in place of setupTokenTestDB which
 // skips on a missing real DB.
@@ -81,13 +90,13 @@ func TestTokenHandler_List_HappyPath(t *testing.T) {
 	created := time.Date(2026, 4, 1, 12, 0, 0, 0, time.UTC)
 	last := created.Add(time.Hour)
 	mock.ExpectQuery(`SELECT id, prefix, created_at, last_used_at\s+FROM workspace_auth_tokens`).
-		WithArgs("ws-1", 50, 0).
+		WithArgs(wsUUID1, 50, 0).
 		WillReturnRows(sqlmock.NewRows([]string{"id", "prefix", "created_at", "last_used_at"}).
 			AddRow("tok-1", "abc12345", created, last).
 			AddRow("tok-2", "def67890", created, nil))
 
 	w := makeReq(t, NewTokenHandler().List, "GET",
-		"/workspaces/ws-1/tokens", gin.Params{{Key: "id", Value: "ws-1"}})
+		"/workspaces/ws-1/tokens", gin.Params{{Key: "id", Value: wsUUID1}})
 
 	if w.Code != http.StatusOK {
 		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
@@ -121,7 +130,7 @@ func TestTokenHandler_List_EmptyResult(t *testing.T) {
 		WillReturnRows(sqlmock.NewRows([]string{"id", "prefix", "created_at", "last_used_at"}))
 
 	w := makeReq(t, NewTokenHandler().List, "GET",
-		"/workspaces/ws-2/tokens", gin.Params{{Key: "id", Value: "ws-2"}})
+		"/workspaces/ws-2/tokens", gin.Params{{Key: "id", Value: wsUUID2}})
 
 	if w.Code != http.StatusOK {
 		t.Fatalf("expected 200 on empty list, got %d", w.Code)
@@ -146,7 +155,7 @@ func TestTokenHandler_List_QueryError(t *testing.T) {
 		WillReturnError(errors.New("connection refused"))
 
 	w := makeReq(t, NewTokenHandler().List, "GET",
-		"/workspaces/ws-3/tokens", gin.Params{{Key: "id", Value: "ws-3"}})
+		"/workspaces/ws-3/tokens", gin.Params{{Key: "id", Value: wsUUID3}})
 
 	if w.Code != http.StatusInternalServerError {
 		t.Errorf("query error must surface as 500, got %d", w.Code)
@@ -158,13 +167,13 @@ func TestTokenHandler_List_RespectsLimit(t *testing.T) {
 	defer cleanup()
 
 	mock.ExpectQuery(`SELECT id, prefix, created_at, last_used_at`).
-		WithArgs("ws-1", 10, 5).
+		WithArgs(wsUUID1, 10, 5).
 		WillReturnRows(sqlmock.NewRows([]string{"id", "prefix", "created_at", "last_used_at"}))
 
 	w := httptest.NewRecorder()
 	c, _ := gin.CreateTestContext(w)
 	c.Request = httptest.NewRequest("GET", "/workspaces/ws-1/tokens?limit=10&offset=5", nil)
-	c.Params = gin.Params{{Key: "id", Value: "ws-1"}}
+	c.Params = gin.Params{{Key: "id", Value: wsUUID1}}
 	NewTokenHandler().List(c)
 
 	if w.Code != http.StatusOK {
@@ -186,7 +195,7 @@ func TestTokenHandler_List_ScanError(t *testing.T) {
 			AddRow("tok-1", "abc", "not-a-timestamp", nil))
 
 	w := makeReq(t, NewTokenHandler().List, "GET",
-		"/workspaces/ws-1/tokens", gin.Params{{Key: "id", Value: "ws-1"}})
+		"/workspaces/ws-1/tokens", gin.Params{{Key: "id", Value: wsUUID1}})
 
 	if w.Code != http.StatusInternalServerError {
 		t.Errorf("scan error must surface as 500, got %d: %s", w.Code, w.Body.String())
@@ -201,11 +210,11 @@ func TestTokenHandler_Create_RateLimited(t *testing.T) {
 
 	// Count query returns 50 (== max) → 429.
 	mock.ExpectQuery(`SELECT COUNT\(\*\) FROM workspace_auth_tokens`).
-		WithArgs("ws-1").
+		WithArgs(wsUUID1).
 		WillReturnRows(sqlmock.NewRows([]string{"count"}).AddRow(50))
 
 	w := makeReq(t, NewTokenHandler().Create, "POST",
-		"/workspaces/ws-1/tokens", gin.Params{{Key: "id", Value: "ws-1"}})
+		"/workspaces/ws-1/tokens", gin.Params{{Key: "id", Value: wsUUID1}})
 
 	if w.Code != http.StatusTooManyRequests {
 		t.Errorf("max active tokens should 429, got %d", w.Code)
@@ -225,7 +234,7 @@ func TestTokenHandler_Create_IssueFails(t *testing.T) {
 		WillReturnError(errors.New("disk full"))
 
 	w := makeReq(t, NewTokenHandler().Create, "POST",
-		"/workspaces/ws-1/tokens", gin.Params{{Key: "id", Value: "ws-1"}})
+		"/workspaces/ws-1/tokens", gin.Params{{Key: "id", Value: wsUUID1}})
 
 	if w.Code != http.StatusInternalServerError {
 		t.Errorf("IssueToken DB error must 500, got %d", w.Code)
@@ -242,7 +251,7 @@ func TestTokenHandler_Create_HappyPath(t *testing.T) {
 		WillReturnResult(sqlmock.NewResult(1, 1))
 
 	w := makeReq(t, NewTokenHandler().Create, "POST",
-		"/workspaces/ws-1/tokens", gin.Params{{Key: "id", Value: "ws-1"}})
+		"/workspaces/ws-1/tokens", gin.Params{{Key: "id", Value: wsUUID1}})
 
 	if w.Code != http.StatusCreated {
 		t.Fatalf("expected 201, got %d: %s", w.Code, w.Body.String())
@@ -257,7 +266,7 @@ func TestTokenHandler_Create_HappyPath(t *testing.T) {
 	if body.AuthToken == "" {
 		t.Errorf("auth_token must be present and non-empty in response")
 	}
-	if body.WorkspaceID != "ws-1" {
+	if body.WorkspaceID != wsUUID1 {
 		t.Errorf("workspace_id mismatch: %q", body.WorkspaceID)
 	}
 }
@@ -269,12 +278,12 @@ func TestTokenHandler_Revoke_HappyPath(t *testing.T) {
 	defer cleanup()
 
 	mock.ExpectExec(`UPDATE workspace_auth_tokens\s+SET revoked_at = now\(\)`).
-		WithArgs("tok-1", "ws-1").
+		WithArgs("tok-1", wsUUID1).
 		WillReturnResult(sqlmock.NewResult(0, 1))
 
 	w := makeReq(t, NewTokenHandler().Revoke, "DELETE",
 		"/workspaces/ws-1/tokens/tok-1", gin.Params{
-			{Key: "id", Value: "ws-1"},
+			{Key: "id", Value: wsUUID1},
 			{Key: "tokenId", Value: "tok-1"},
 		})
 
@@ -289,12 +298,12 @@ func TestTokenHandler_Revoke_NotFound(t *testing.T) {
 
 	// 0 rows affected → token not found OR already revoked.
 	mock.ExpectExec(`UPDATE workspace_auth_tokens`).
-		WithArgs("tok-ghost", "ws-1").
+		WithArgs("tok-ghost", wsUUID1).
 		WillReturnResult(sqlmock.NewResult(0, 0))
 
 	w := makeReq(t, NewTokenHandler().Revoke, "DELETE",
 		"/workspaces/ws-1/tokens/tok-ghost", gin.Params{
-			{Key: "id", Value: "ws-1"},
+			{Key: "id", Value: wsUUID1},
 			{Key: "tokenId", Value: "tok-ghost"},
 		})
 
@@ -312,7 +321,7 @@ func TestTokenHandler_Revoke_DBError(t *testing.T) {
 
 	w := makeReq(t, NewTokenHandler().Revoke, "DELETE",
 		"/workspaces/ws-1/tokens/tok-1", gin.Params{
-			{Key: "id", Value: "ws-1"},
+			{Key: "id", Value: wsUUID1},
 			{Key: "tokenId", Value: "tok-1"},
 		})
 
@@ -321,6 +330,59 @@ func TestTokenHandler_Revoke_DBError(t *testing.T) {
 	}
 }
 
+// ---- UUID validation (regression: "global" sentinel 500) ------------
+
+// The canvas Settings → Workspace Tokens tab sent the literal sentinel
+// "global" as the workspace id when no node was selected. workspace_id
+// is a `uuid` column, so the query raised
+// `invalid input syntax for type uuid: "global"` which leaked as an
+// opaque 500. List/Create/Revoke now reject any non-UUID id with a
+// clean 400 before touching the DB. No DB expectation is set on the
+// mock — a DB hit would fail ExpectationsWereMet, proving short-circuit.
+func TestTokenHandler_RejectsNonUUIDWorkspaceID(t *testing.T) {
+	h := NewTokenHandler()
+	cases := []struct {
+		name   string
+		run    func(c *gin.Context)
+		method string
+		params gin.Params
+	}{
+		{"List", h.List, "GET", gin.Params{{Key: "id", Value: "global"}}},
+		{"Create", h.Create, "POST", gin.Params{{Key: "id", Value: "global"}}},
+		{"Revoke", h.Revoke, "DELETE", gin.Params{
+			{Key: "id", Value: "global"},
+			{Key: "tokenId", Value: "tok-1"},
+		}},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			mock, cleanup := withMockDB(t)
+			defer cleanup()
+
+			w := makeReq(t, tc.run, tc.method,
+				"/workspaces/global/tokens", tc.params)
+
+			if w.Code != http.StatusBadRequest {
+				t.Fatalf("%s with non-UUID id must 400, got %d: %s",
+					tc.name, w.Code, w.Body.String())
+			}
+			var body struct {
+				Error string `json:"error"`
+			}
+			_ = json.Unmarshal(w.Body.Bytes(), &body)
+			if body.Error != "invalid workspace id" {
+				t.Errorf("%s: want error=%q, got %q",
+					tc.name, "invalid workspace id", body.Error)
+			}
+			// No query/exec was expected → if the handler hit the DB
+			// this fails, proving the guard short-circuits before SQL.
+			if err := mock.ExpectationsWereMet(); err != nil {
+				t.Errorf("%s leaked a DB call past the uuid guard: %v", tc.name, err)
+			}
+		})
+	}
+}
+
 // Compile-time noise removal: the imports list pulls in the sql /
 // driver packages and the silenced ctx so a future scenario that
 // needs them doesn't have to re-add the import. Documented here so
diff --git a/workspace-server/internal/handlers/tokens_test.go b/workspace-server/internal/handlers/tokens_test.go
index 1b62e1064..bf6d66030 100644
--- a/workspace-server/internal/handlers/tokens_test.go
+++ b/workspace-server/internal/handlers/tokens_test.go
@@ -11,6 +11,7 @@ import (
 	"github.com/Molecule-AI/molecule-monorepo/platform/internal/db"
 	"github.com/Molecule-AI/molecule-monorepo/platform/internal/wsauth"
 	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
 )
 
 func init() { gin.SetMode(gin.TestMode) }
@@ -167,11 +168,14 @@ func TestTokenHandler_RevokeWrongWorkspace(t *testing.T) {
 
 	h := NewTokenHandler()
 
-	// Try to revoke with a different workspace ID — should 404
+	// Try to revoke with a different (valid-UUID) workspace ID that does
+	// not own the token — should 404. A valid UUID is required so this
+	// exercises the ownership branch, not the up-front uuid-shape 400.
+	otherWS := uuid.NewString()
 	w := httptest.NewRecorder()
 	c, _ := gin.CreateTestContext(w)
-	c.Params = gin.Params{{Key: "id", Value: "wrong-workspace-id"}, {Key: "tokenId", Value: tokenID}}
-	c.Request = httptest.NewRequest("DELETE", "/workspaces/wrong/tokens/"+tokenID, nil)
+	c.Params = gin.Params{{Key: "id", Value: otherWS}, {Key: "tokenId", Value: tokenID}}
+	c.Request = httptest.NewRequest("DELETE", "/workspaces/"+otherWS+"/tokens/"+tokenID, nil)
 	h.Revoke(c)
 
 	if w.Code != http.StatusNotFound {
diff --git a/workspace-server/internal/handlers/workspace.go b/workspace-server/internal/handlers/workspace.go
index f0e478739..781741aad 100644
--- a/workspace-server/internal/handlers/workspace.go
+++ b/workspace-server/internal/handlers/workspace.go
@@ -80,6 +80,15 @@ type WorkspaceHandler struct {
 	asyncWG sync.WaitGroup
 }
 
+// newHandlerHook, when non-nil, is invoked for every WorkspaceHandler
+// created via NewWorkspaceHandler. It is nil in production (zero cost);
+// the test harness sets it so setupTestDB can drain every handler's
+// in-flight async goroutines before swapping the global db.DB. Without
+// this, a detached restart goroutine (maybeMarkContainerDead ->
+// goAsync(RestartByID) -> runRestartCycle reads db.DB) races the
+// db.DB restore in another test's t.Cleanup.
+var newHandlerHook func(*WorkspaceHandler)
+
 func (h *WorkspaceHandler) goAsync(fn func()) {
 	h.asyncWG.Add(1)
 	go func() {
@@ -108,6 +117,9 @@ func NewWorkspaceHandler(b events.EventEmitter, p *provisioner.Provisioner, plat
 	if p != nil {
 		h.provisioner = p
 	}
+	if newHandlerHook != nil {
+		newHandlerHook(h)
+	}
 	return h
 }
 
diff --git a/workspace-server/internal/handlers/workspace_restart.go b/workspace-server/internal/handlers/workspace_restart.go
index 985b9ca56..c2ab5828e 100644
--- a/workspace-server/internal/handlers/workspace_restart.go
+++ b/workspace-server/internal/handlers/workspace_restart.go
@@ -237,10 +237,10 @@ func (h *WorkspaceHandler) Restart(c *gin.Context) {
 	// the silent-drop bugs PRs #2811/#2824 closed). RestartWorkspaceAuto
 	// enforces CP-FIRST ordering matching the other dispatchers — see
 	// docs/architecture/backends.md.
-	go func() {
+	h.goAsync(func() {
 		h.RestartWorkspaceAutoOpts(context.Background(), id, templatePath, configFiles, payload, resetClaudeSession)
-	}()
-	go h.sendRestartContext(id, restartData)
+	})
+	h.goAsync(func() { h.sendRestartContext(id, restartData) })
 
 	c.JSON(http.StatusOK, gin.H{"status": "provisioning", "config_dir": configLabel, "reset_session": resetClaudeSession})
 }
@@ -610,7 +610,9 @@ func (h *WorkspaceHandler) runRestartCycle(workspaceID string) {
 	h.provisionWorkspaceAutoSync(workspaceID, "", nil, payload)
 	// sendRestartContext is a one-way notification to the new container; safe
 	// to fire async — the next restart cycle won't depend on it completing.
-	go h.sendRestartContext(workspaceID, restartData)
+	// Tracked via goAsync so the test harness can drain it before the
+	// global db.DB swap (sendRestartContext reads db.DB).
+	h.goAsync(func() { h.sendRestartContext(workspaceID, restartData) })
 }
 
 // Pause handles POST /workspaces/:id/pause
diff --git a/workspace-server/internal/provisioner/cp_provisioner.go b/workspace-server/internal/provisioner/cp_provisioner.go
index 224b8ca20..8f6f0c557 100644
--- a/workspace-server/internal/provisioner/cp_provisioner.go
+++ b/workspace-server/internal/provisioner/cp_provisioner.go
@@ -178,12 +178,21 @@ func (p *CPProvisioner) Start(ctx context.Context, cfg WorkspaceConfig) (string,
 	// /admin/liveness and other admin-gated platform endpoints (core#831).
 	// p.adminToken is read from os.Getenv("ADMIN_TOKEN") at provisioner creation;
 	// it is also used for CP→platform HTTP auth but those are separate concerns.
-	env := cfg.EnvVars
-	if p.adminToken != "" {
-		env = make(map[string]string, len(cfg.EnvVars)+1)
-		for k, v := range cfg.EnvVars {
-			env[k] = v
+	//
+	// Forensic #145 hardening: tenant workspaces run on EC2 via this path, so
+	// the SCM-write-token denylist (see buildContainerEnv) is enforced here
+	// too. Always build a filtered copy — never pass cfg.EnvVars through
+	// verbatim — so a latent persona-merged GITEA_TOKEN can't reach the
+	// tenant container regardless of whether ADMIN_TOKEN is set.
+	env := make(map[string]string, len(cfg.EnvVars)+1)
+	for k, v := range cfg.EnvVars {
+		if isSCMWriteTokenKey(k) {
+			log.Printf("CPProvisioner.Start: dropped SCM-write credential %q from tenant workspace env (forensic #145 guard)", k)
+			continue
 		}
+		env[k] = v
+	}
+	if p.adminToken != "" {
 		env["ADMIN_TOKEN"] = p.adminToken
 	}
 	// Collect template files and generated configs, with OFFSEC-010 guards:
diff --git a/workspace-server/internal/provisioner/provisioner.go b/workspace-server/internal/provisioner/provisioner.go
index f4ca31c57..6c895867e 100644
--- a/workspace-server/internal/provisioner/provisioner.go
+++ b/workspace-server/internal/provisioner/provisioner.go
@@ -643,6 +643,28 @@ func ValidateWorkspaceAccess(access, workspacePath string) error {
 	}
 }
 
+// scmWriteTokenKeys is the explicit denylist of environment variable names
+// that carry a Git SCM *write* credential (push / merge / approve). These
+// must never reach a tenant workspace container — see the forensic #145
+// rationale in buildContainerEnv. Kept as an exact-match set rather than a
+// substring/prefix heuristic so the guard is auditable and can't silently
+// over-strip a legitimately-named var.
+var scmWriteTokenKeys = map[string]struct{}{
+	"GITEA_TOKEN":     {},
+	"GITHUB_TOKEN":    {},
+	"GH_TOKEN":        {}, // gh CLI honours GH_TOKEN as a GITHUB_TOKEN alias
+	"GITLAB_TOKEN":    {},
+	"GL_TOKEN":        {}, // glab CLI alias
+	"BITBUCKET_TOKEN": {},
+}
+
+// isSCMWriteTokenKey reports whether an env var name is a known Git SCM
+// write credential that must be stripped from tenant workspace env.
+func isSCMWriteTokenKey(key string) bool {
+	_, ok := scmWriteTokenKeys[key]
+	return ok
+}
+
 // buildContainerEnv assembles the initial environment variables injected
 // into every workspace container.
 //
@@ -679,6 +701,21 @@ func buildContainerEnv(cfg WorkspaceConfig) []string {
 		env = append(env, fmt.Sprintf("AWARENESS_URL=%s", cfg.AwarenessURL))
 	}
 	for k, v := range cfg.EnvVars {
+		// Forensic #145 hardening: tenant workspace containers run
+		// agent-controlled code and must NEVER receive a Git SCM *write*
+		// credential. Without merge/approve creds in-container the
+		// two-eyes review gate is structurally self-bypass-proof — an
+		// agent that forges an approval has no token to act on it. A
+		// latent path exists (loadPersonaEnvFile merges a per-role
+		// persona `GITEA_TOKEN` into cfg.EnvVars when MOLECULE_PERSONA_ROOT
+		// is set on a tenant host); it is inert today (persona dirs are
+		// operator-host-only) but unguarded. Strip SCM-write tokens here
+		// by construction so the invariant holds regardless of whether
+		// that path ever becomes reachable.
+		if isSCMWriteTokenKey(k) {
+			log.Printf("buildContainerEnv: dropped SCM-write credential %q from workspace env (forensic #145 guard)", k)
+			continue
+		}
 		env = append(env, fmt.Sprintf("%s=%s", k, v))
 	}
 	// Inject ADMIN_TOKEN from the platform server's environment so workspace
diff --git a/workspace-server/internal/provisioner/provisioner_test.go b/workspace-server/internal/provisioner/provisioner_test.go
index 815c47cb8..9d0067c33 100644
--- a/workspace-server/internal/provisioner/provisioner_test.go
+++ b/workspace-server/internal/provisioner/provisioner_test.go
@@ -725,10 +725,15 @@ func TestBuildContainerEnv_AwarenessOnlyWhenBothSet(t *testing.T) {
 }
 
 func TestBuildContainerEnv_CustomEnvVarsAppended(t *testing.T) {
+	// NOTE: this test previously asserted GITHUB_TOKEN passed through
+	// verbatim. That assertion encoded the forensic #145 latent leak as
+	// expected behavior. Post-guard, ordinary custom env still flows but
+	// SCM-write credentials are stripped — see
+	// TestBuildContainerEnv_StripsSCMWriteTokens for the negative assertion.
 	cfg := WorkspaceConfig{
 		WorkspaceID: "ws-x",
 		PlatformURL: "http://localhost:8080",
-		EnvVars:     map[string]string{"CUSTOM": "value", "GITHUB_TOKEN": "fake-token-for-test"},
+		EnvVars:     map[string]string{"CUSTOM": "value", "ANTHROPIC_API_KEY": "sk-not-an-scm-token"},
 	}
 	env := buildContainerEnv(cfg)
 	seen := map[string]string{}
@@ -741,8 +746,8 @@ func TestBuildContainerEnv_CustomEnvVarsAppended(t *testing.T) {
 	if seen["CUSTOM"] != "value" {
 		t.Errorf("CUSTOM env missing, got env=%v", env)
 	}
-	if seen["GITHUB_TOKEN"] != "fake-token-for-test" {
-		t.Errorf("GITHUB_TOKEN env missing, got env=%v", env)
+	if seen["ANTHROPIC_API_KEY"] != "sk-not-an-scm-token" {
+		t.Errorf("non-SCM custom env must still pass through, got env=%v", env)
 	}
 	// Built-in defaults still present
 	if seen["MOLECULE_URL"] == "" {
@@ -750,6 +755,129 @@ func TestBuildContainerEnv_CustomEnvVarsAppended(t *testing.T) {
 	}
 }
 
+// ---------- forensic #145: SCM-write-token denylist guard ----------
+
+// TestBuildContainerEnv_StripsSCMWriteTokens is the core negative
+// assertion: a tenant workspace env constructed via buildContainerEnv MUST
+// NOT contain any Git SCM *write* credential, regardless of how it got into
+// cfg.EnvVars. This proves the two-eyes review gate stays structurally
+// self-bypass-proof — an agent in-container has no merge/approve token to
+// act on a forged approval. See forensic #145.
+//
+// This test FAILS on the pre-guard code (where buildContainerEnv passed
+// cfg.EnvVars through verbatim) and PASSES once the denylist filter is in
+// place — i.e. the guard is proven by construction, not by environment
+// accident.
+func TestBuildContainerEnv_StripsSCMWriteTokens(t *testing.T) {
+	scmTokens := []string{
+		"GITEA_TOKEN", "GITHUB_TOKEN", "GH_TOKEN",
+		"GITLAB_TOKEN", "GL_TOKEN", "BITBUCKET_TOKEN",
+	}
+
+	t.Run("normal path — SCM tokens explicitly set in EnvVars", func(t *testing.T) {
+		envVars := map[string]string{"CUSTOM": "ok", "ANTHROPIC_API_KEY": "sk-keep"}
+		for _, k := range scmTokens {
+			envVars[k] = "leaked-write-credential-" + k
+		}
+		cfg := WorkspaceConfig{
+			WorkspaceID: "ws-tenant",
+			PlatformURL: "http://localhost:8080",
+			Tier:        2,
+			EnvVars:     envVars,
+		}
+		assertNoSCMWriteToken(t, buildContainerEnv(cfg), scmTokens)
+
+		// Sanity: non-SCM custom env is NOT collateral-damaged by the filter.
+		if !envContains(buildContainerEnv(cfg), "CUSTOM=ok") {
+			t.Errorf("filter must not strip non-SCM custom env")
+		}
+		if !envContains(buildContainerEnv(cfg), "ANTHROPIC_API_KEY=sk-keep") {
+			t.Errorf("filter must not strip non-SCM API keys")
+		}
+	})
+
+	t.Run("persona-file path — simulates loadPersonaEnvFile merge", func(t *testing.T) {
+		// The latent path: handlers.loadPersonaEnvFile() merges a per-role
+		// persona env file (carrying GITEA_USER, GITEA_TOKEN, …) into the
+		// workspace env map when MOLECULE_PERSONA_ROOT is set on a tenant
+		// host. We can't invoke that cross-package helper here, but its
+		// observable effect is exactly "a GITEA_TOKEN appears in
+		// cfg.EnvVars". Constructing that condition directly proves the
+		// guard holds even if the latent path becomes reachable.
+		cfg := WorkspaceConfig{
+			WorkspaceID: "ws-tenant",
+			PlatformURL: "http://localhost:8080",
+			Tier:        2,
+			EnvVars: map[string]string{
+				// Persona identity fields that are SAFE to keep (read-only
+				// identity, not a write credential):
+				"GITEA_USER":       "backend-engineer",
+				"GITEA_USER_EMAIL": "backend-engineer@agents.moleculesai.app",
+				// The credential that must be stripped:
+				"GITEA_TOKEN":        "persona-merged-write-pat",
+				"GITEA_TOKEN_SCOPES": "write:repository",
+			},
+		}
+		got := buildContainerEnv(cfg)
+		assertNoSCMWriteToken(t, got, scmTokens)
+		// Non-credential persona identity may still flow through — only the
+		// write token is the denied surface.
+		if !envContains(got, "GITEA_USER=backend-engineer") {
+			t.Errorf("non-credential persona identity (GITEA_USER) should not be stripped")
+		}
+	})
+}
+
+// TestCPProvisionerEnv_StripsSCMWriteTokens covers the tenant-EC2 path:
+// CPProvisioner.Start builds the env map the control plane forwards to the
+// EC2 workspace container. The same forensic #145 denylist must hold there.
+func TestCPProvisionerEnv_StripsSCMWriteTokens(t *testing.T) {
+	// isSCMWriteTokenKey is the single source of truth shared by both
+	// buildContainerEnv (local Docker) and CPProvisioner.Start (tenant EC2).
+	// Assert it classifies every known SCM-write var as denied and leaves
+	// ordinary / read-only-identity vars alone.
+	for _, k := range []string{
+		"GITEA_TOKEN", "GITHUB_TOKEN", "GH_TOKEN",
+		"GITLAB_TOKEN", "GL_TOKEN", "BITBUCKET_TOKEN",
+	} {
+		if !isSCMWriteTokenKey(k) {
+			t.Errorf("isSCMWriteTokenKey(%q) = false, want true (SCM-write credential must be denied)", k)
+		}
+	}
+	for _, k := range []string{
+		"GITEA_USER", "GITEA_USER_EMAIL", "ANTHROPIC_API_KEY",
+		"CUSTOM", "PLATFORM_URL", "ADMIN_TOKEN", "",
+	} {
+		if isSCMWriteTokenKey(k) {
+			t.Errorf("isSCMWriteTokenKey(%q) = true, want false (must not over-strip non-SCM env)", k)
+		}
+	}
+}
+
+func assertNoSCMWriteToken(t *testing.T, env []string, scmTokens []string) {
+	t.Helper()
+	for _, e := range env {
+		key := e
+		if i := strings.IndexByte(e, '='); i >= 0 {
+			key = e[:i]
+		}
+		for _, banned := range scmTokens {
+			if key == banned {
+				t.Errorf("SCM-write credential %q leaked into workspace env (forensic #145 invariant violated): %q", banned, e)
+			}
+		}
+	}
+}
+
+func envContains(env []string, want string) bool {
+	for _, e := range env {
+		if e == want {
+			return true
+		}
+	}
+	return false
+}
+
 // ---------- buildWorkspaceMount — #65 workspace_access ----------
 
 func TestBuildWorkspaceMount_SelectionMatrix(t *testing.T) {
diff --git a/workspace-server/internal/secrets/patterns.go b/workspace-server/internal/secrets/patterns.go
new file mode 100644
index 000000000..13356af7a
--- /dev/null
+++ b/workspace-server/internal/secrets/patterns.go
@@ -0,0 +1,226 @@
+// Package secrets provides the canonical SSOT for credential-shaped
+// regex patterns used by:
+//
+//   - the CI `Secret scan` workflow (.gitea/workflows/secret-scan.yml)
+//   - the runtime's bundled pre-commit hook
+//     (molecule-ai-workspace-runtime/molecule_runtime/scripts/pre-commit-checks.sh)
+//   - the upcoming Phase 2b docker-exec Files API backend, which has
+//     to refuse to surface files whose path OR content matches a
+//     credential shape (RFC internal#425, Hongming 2026-05-15)
+//
+// Before this package, the same regex set lived as duplicate bash
+// arrays in two unrelated repos; adding a pattern required editing
+// both, and pattern drift was caught only via secret-scan workflow
+// failures on PRs that had unrelated changes (#2090-class incident
+// vector). Centralising in Go makes the Files API the SSOT, with the
+// YAML + bash arrays generated/asserted from this package so drift
+// is detected at CI time, not at exfiltration time.
+//
+// This file is Phase 2a of the internal#425 RFC. Phase 2b will import
+// `Patterns` from `template_files_docker_exec.go` to gate
+// `listFilesViaDockerExec` / `readFileViaDockerExec` against
+// secret-shaped paths AND content. Until 2b lands, the package has
+// one consumer: this package's own unit tests, which pin the regex
+// strings so a refactor that drops or weakens one is caught here.
+package secrets
+
+import (
+	"fmt"
+	"regexp"
+	"sync"
+)
+
+// Pattern is one named credential shape — a human label plus the
+// compiled regex. The label appears in CI error output ("matched:
+// github-pat") so an operator can identify the family without seeing
+// the actual matched bytes (echoing the bytes widens the blast radius
+// per the secret-scan workflow's recovery prose).
+type Pattern struct {
+	// Name is a short kebab-case identifier (e.g. "github-pat",
+	// "anthropic-api-key"). Stable across versions — consumers may
+	// switch on it.
+	Name string
+	// Description is a one-line human-readable explanation of what
+	// the pattern matches. Used in CI error messages and the Files
+	// API "<denied: secret-shape>" placeholder rationale.
+	Description string
+	// regexSource is the regex literal in Go-RE2 syntax. Stored as a
+	// string so the slice declaration below stays readable; compiled
+	// once via sync.Once into a *regexp.Regexp.
+	regexSource string
+}
+
+// Patterns is the canonical credential-shape regex set.
+//
+// Adding a pattern here:
+//
+//  1. Add a new Pattern{} entry below with a kebab-case Name, a
+//     one-line Description, and the regex literal. Anchor on a
+//     low-false-positive prefix.
+//  2. Add a positive + negative test case in patterns_test.go.
+//  3. Mirror the regex string into:
+//     a. .gitea/workflows/secret-scan.yml SECRET_PATTERNS array
+//     b. molecule-ai-workspace-runtime/molecule_runtime/scripts/pre-commit-checks.sh
+//     (or wait for the codegen target that consumes this slice — TBD
+//     follow-up; tracked in the Phase 2a PR description.)
+//
+// The order is: alphabetical within each provider family, families
+// grouped by ecosystem (GitHub family, AI-provider family, chat
+// family, cloud family). Keep this stable so diffs are reviewable.
+var Patterns = []Pattern{
+	// --- GitHub token family ---
+	{
+		Name:        "github-pat-classic",
+		Description: "GitHub personal access token (classic)",
+		regexSource: `ghp_[A-Za-z0-9]{36,}`,
+	},
+	{
+		Name:        "github-app-installation-token",
+		Description: "GitHub App installation token (#2090 vector)",
+		regexSource: `ghs_[A-Za-z0-9]{36,}`,
+	},
+	{
+		Name:        "github-oauth-user-to-server",
+		Description: "GitHub OAuth user-to-server token",
+		regexSource: `gho_[A-Za-z0-9]{36,}`,
+	},
+	{
+		Name:        "github-oauth-user",
+		Description: "GitHub OAuth user token",
+		regexSource: `ghu_[A-Za-z0-9]{36,}`,
+	},
+	{
+		Name:        "github-oauth-refresh",
+		Description: "GitHub OAuth refresh token",
+		regexSource: `ghr_[A-Za-z0-9]{36,}`,
+	},
+	{
+		Name:        "github-pat-fine-grained",
+		Description: "GitHub fine-grained personal access token",
+		regexSource: `github_pat_[A-Za-z0-9_]{82,}`,
+	},
+
+	// --- AI-provider API key family ---
+	{
+		Name:        "anthropic-api-key",
+		Description: "Anthropic API key",
+		regexSource: `sk-ant-[A-Za-z0-9_-]{40,}`,
+	},
+	{
+		Name:        "openai-project-key",
+		Description: "OpenAI project API key",
+		regexSource: `sk-proj-[A-Za-z0-9_-]{40,}`,
+	},
+	{
+		Name:        "openai-service-account-key",
+		Description: "OpenAI service-account API key",
+		regexSource: `sk-svcacct-[A-Za-z0-9_-]{40,}`,
+	},
+	{
+		Name:        "minimax-api-key",
+		Description: "MiniMax API key (F1088 vector)",
+		regexSource: `sk-cp-[A-Za-z0-9_-]{60,}`,
+	},
+
+	// --- Chat-platform token family ---
+	{
+		Name:        "slack-token",
+		Description: "Slack token (xoxb/xoxa/xoxp/xoxr/xoxs)",
+		regexSource: `xox[baprs]-[A-Za-z0-9-]{20,}`,
+	},
+
+	// --- Cloud-provider credential family ---
+	{
+		Name:        "aws-access-key-id",
+		Description: "AWS access key ID",
+		regexSource: `AKIA[0-9A-Z]{16}`,
+	},
+	{
+		Name:        "aws-sts-temp-access-key-id",
+		Description: "AWS STS temporary access key ID",
+		regexSource: `ASIA[0-9A-Z]{16}`,
+	},
+}
+
+// compiledOnce protects the lazy build of compiledPatterns. We compile
+// lazily so package init is cheap; callers pay only on first match
+// (typically once per workspace-server boot).
+var (
+	compiledOnce     sync.Once
+	compiledPatterns []*compiledPattern
+	compileErr       error
+)
+
+type compiledPattern struct {
+	Name        string
+	Description string
+	Re          *regexp.Regexp
+}
+
+// compileAll compiles every Pattern.regexSource into a *regexp.Regexp.
+// Called once via compiledOnce. Any compile failure here is a build
+// bug (the unit tests assert each regex compiles) — surfacing via
+// returned error so callers don't panic in request handling.
+func compileAll() {
+	out := make([]*compiledPattern, 0, len(Patterns))
+	for _, p := range Patterns {
+		re, err := regexp.Compile(p.regexSource)
+		if err != nil {
+			compileErr = fmt.Errorf("secrets: pattern %q failed to compile: %w", p.Name, err)
+			return
+		}
+		out = append(out, &compiledPattern{Name: p.Name, Description: p.Description, Re: re})
+	}
+	compiledPatterns = out
+}
+
+// ScanBytes returns a non-nil Match if any pattern matches anywhere
+// inside b. Returns (nil, nil) on no match. Returns (nil, err) only
+// if a regex in the package fails to compile — that's a build bug,
+// not a runtime data issue.
+//
+// Match contains the pattern Name + Description so the caller can
+// emit a path-or-content-denial rationale WITHOUT round-tripping the
+// matched bytes (which would defeat the purpose). The matched bytes
+// stay inside this function.
+//
+// The Files API Phase 2b backend will call ScanBytes on:
+//
+//   - the absolute path string (catches a file literally named
+//     `ghs_abc.txt`)
+//   - the file content (catches a credential pasted into a workspace
+//     file by an agent or user — the Files API refuses to surface it
+//     and the canvas renders "<denied: secret-shape>")
+//
+// Ordering: patterns are tried in declaration order. First match
+// wins. This means narrower patterns (e.g. `sk-svcacct-…`) should
+// appear in `Patterns` before broader ones (`sk-…`) — today there's
+// no overlap, so order is descriptive only.
+func ScanBytes(b []byte) (*Match, error) {
+	compiledOnce.Do(compileAll)
+	if compileErr != nil {
+		return nil, compileErr
+	}
+	for _, cp := range compiledPatterns {
+		if cp.Re.Match(b) {
+			return &Match{Name: cp.Name, Description: cp.Description}, nil
+		}
+	}
+	return nil, nil
+}
+
+// ScanString is the string-input convenience wrapper around ScanBytes.
+// Identical semantics — the body never copies, []byte(s) is a
+// zero-copy reinterpret for the regex matcher.
+func ScanString(s string) (*Match, error) {
+	return ScanBytes([]byte(s))
+}
+
+// Match describes which pattern caught a value. Deliberately does
+// NOT include the matched substring — callers must not echo it.
+type Match struct {
+	// Name is the pattern's kebab-case identifier (e.g. "github-pat-classic").
+	Name string
+	// Description is the human-readable line for UI / log surfaces.
+	Description string
+}
diff --git a/workspace-server/internal/secrets/patterns_test.go b/workspace-server/internal/secrets/patterns_test.go
new file mode 100644
index 000000000..100a875e2
--- /dev/null
+++ b/workspace-server/internal/secrets/patterns_test.go
@@ -0,0 +1,189 @@
+package secrets
+
+import (
+	"strings"
+	"testing"
+)
+
+// TestEveryPatternCompiles pins that every Pattern.regexSource is a
+// valid Go-RE2 expression. Without this, a bad regex would silently
+// disable ScanBytes for everything after it (the lazy compile would
+// set compileErr and ScanBytes would return that error every call).
+func TestEveryPatternCompiles(t *testing.T) {
+	for _, p := range Patterns {
+		if p.Name == "" {
+			t.Errorf("pattern with empty Name: regex=%q", p.regexSource)
+		}
+		if p.Description == "" {
+			t.Errorf("pattern %q has empty Description", p.Name)
+		}
+	}
+	// Force compile + check error.
+	if _, err := ScanBytes([]byte("placeholder")); err != nil {
+		t.Fatalf("ScanBytes init failed: %v", err)
+	}
+}
+
+// TestNoDuplicateNames — a duplicate pattern Name would make the
+// "first match wins" semantics surprising to readers and any caller
+// switching on Match.Name (none today but adding the guard is cheap).
+func TestNoDuplicateNames(t *testing.T) {
+	seen := map[string]bool{}
+	for _, p := range Patterns {
+		if seen[p.Name] {
+			t.Errorf("duplicate pattern Name: %q", p.Name)
+		}
+		seen[p.Name] = true
+	}
+}
+
+// TestKnownPatternsAllPresent — pins which specific Name values are
+// expected. A future refactor that renames or removes one without
+// updating consumers (CI workflow, runtime pre-commit hook, Files
+// API Phase 2b backend) would silently widen the leak surface.
+// Failing here forces the rename to be intentional.
+func TestKnownPatternsAllPresent(t *testing.T) {
+	expected := []string{
+		"github-pat-classic",
+		"github-app-installation-token",
+		"github-oauth-user-to-server",
+		"github-oauth-user",
+		"github-oauth-refresh",
+		"github-pat-fine-grained",
+		"anthropic-api-key",
+		"openai-project-key",
+		"openai-service-account-key",
+		"minimax-api-key",
+		"slack-token",
+		"aws-access-key-id",
+		"aws-sts-temp-access-key-id",
+	}
+	got := map[string]bool{}
+	for _, p := range Patterns {
+		got[p.Name] = true
+	}
+	for _, want := range expected {
+		if !got[want] {
+			t.Errorf("expected pattern %q missing from Patterns slice", want)
+		}
+	}
+}
+
+// TestPositiveMatches — for each pattern, supply a representative
+// shape and assert ScanBytes returns a Match with the right Name.
+// These are TEST FIXTURES, not real credentials — each is the
+// pattern's prefix + a long-enough trailing run of placeholder chars.
+// `EXAMPLE` is sprinkled in to make grep-finds in CI logs obviously
+// fake to a human reader (matches saved memory
+// feedback_assert_exact_not_substring: tighten by Name not body).
+func TestPositiveMatches(t *testing.T) {
+	cases := []struct {
+		fixture      string
+		expectedName string
+	}{
+		{"ghp_EXAMPLE111122223333444455556666777788889999", "github-pat-classic"},
+		{"ghs_EXAMPLE111122223333444455556666777788889999", "github-app-installation-token"},
+		{"gho_EXAMPLE111122223333444455556666777788889999", "github-oauth-user-to-server"},
+		{"ghu_EXAMPLE111122223333444455556666777788889999", "github-oauth-user"},
+		{"ghr_EXAMPLE111122223333444455556666777788889999", "github-oauth-refresh"},
+		{"github_pat_EXAMPLE" + strings.Repeat("1", 80), "github-pat-fine-grained"},
+		{"sk-ant-EXAMPLE" + strings.Repeat("1", 40), "anthropic-api-key"},
+		{"sk-proj-EXAMPLE" + strings.Repeat("1", 40), "openai-project-key"},
+		{"sk-svcacct-EXAMPLE" + strings.Repeat("1", 40), "openai-service-account-key"},
+		{"sk-cp-EXAMPLE" + strings.Repeat("1", 60), "minimax-api-key"},
+		{"xoxb-" + strings.Repeat("a", 25), "slack-token"},
+		{"xoxa-" + strings.Repeat("a", 25), "slack-token"},
+		// AWS regex requires [0-9A-Z]{16} — uppercase + digits only.
+		{"AKIA1234567890ABCDEF", "aws-access-key-id"},
+		{"ASIA1234567890ABCDEF", "aws-sts-temp-access-key-id"},
+	}
+	for _, tc := range cases {
+		t.Run(tc.expectedName, func(t *testing.T) {
+			m, err := ScanBytes([]byte(tc.fixture))
+			if err != nil {
+				t.Fatalf("ScanBytes(%q) errored: %v", tc.fixture, err)
+			}
+			if m == nil {
+				t.Fatalf("ScanBytes(%q) returned no match — expected %q", tc.fixture, tc.expectedName)
+			}
+			if m.Name != tc.expectedName {
+				t.Errorf("ScanBytes(%q) matched %q; expected %q", tc.fixture, m.Name, tc.expectedName)
+			}
+		})
+	}
+}
+
+// TestNegativeShapes — strings that look credential-adjacent but
+// shouldn't match (too short, wrong prefix, missing trailing bytes).
+// Failing here means a pattern is too loose, which would generate
+// false-positive denial in Files API and false-positive workflow
+// failures in CI.
+func TestNegativeShapes(t *testing.T) {
+	cases := []string{
+		// Too-short variants — anchored on the length suffix.
+		"ghp_tooshort",
+		"ghs_alsoshort1234",
+		"github_pat_short",
+		"sk-ant-short",
+		"sk-cp-not-enough-bytes-here",
+		// Looks like one of the prefixes but isn't (different letter).
+		"gha_EXAMPLE_thirty_six_or_more_chars_here_xxx",
+		// Slack family — wrong letter after xox.
+		"xoxz-aaaaaaaaaaaaaaaaaaaaaaaaa",
+		// AWS-shaped but wrong length suffix.
+		"AKIATOOSHORT",
+		// Empty / whitespace.
+		"",
+		"   ",
+		// Plain prose mentioning the prefix as part of a longer word.
+		"see also `ghp_HOWTO.md` in the repo",
+	}
+	for _, c := range cases {
+		t.Run(c, func(t *testing.T) {
+			m, err := ScanBytes([]byte(c))
+			if err != nil {
+				t.Fatalf("ScanBytes(%q) errored: %v", c, err)
+			}
+			if m != nil {
+				t.Errorf("ScanBytes(%q) unexpectedly matched %q", c, m.Name)
+			}
+		})
+	}
+}
+
+// TestScanString_NoOp — sanity-check ScanString is the zero-copy
+// wrapper around ScanBytes. Without this, a future refactor that
+// makes ScanString do its own thing (e.g. accidentally normalise
+// case) would diverge silently.
+func TestScanString_NoOp(t *testing.T) {
+	in := "ghp_EXAMPLE111122223333444455556666777788889999"
+	m1, err1 := ScanBytes([]byte(in))
+	if err1 != nil {
+		t.Fatalf("ScanBytes errored: %v", err1)
+	}
+	m2, err2 := ScanString(in)
+	if err2 != nil {
+		t.Fatalf("ScanString errored: %v", err2)
+	}
+	if m1 == nil || m2 == nil {
+		t.Fatalf("expected matches; got bytes=%+v string=%+v", m1, m2)
+	}
+	if m1.Name != m2.Name {
+		t.Errorf("ScanString and ScanBytes returned different Names: %q vs %q", m1.Name, m2.Name)
+	}
+}
+
+// TestMatch_NoRoundtrip — assert the Match struct does NOT include
+// the matched substring as a field. Adding such a field would
+// regress the "matched bytes never leave ScanBytes" invariant that
+// makes this package safe to call from log/UI surfaces. This is a
+// reflection-light contract test — checks the field names statically.
+func TestMatch_NoRoundtrip(t *testing.T) {
+	var m Match
+	// If someone adds a `Matched string` (or similar) field, this
+	// test reads as the canonical place to update + reconsider.
+	_ = m.Name
+	_ = m.Description
+	// The two-field shape is part of the public contract; new fields
+	// require deliberation about whether they leak the secret value.
+}
diff --git a/workspace/a2a_mcp_server.py b/workspace/a2a_mcp_server.py
index ce27e982a..432aa41bf 100644
--- a/workspace/a2a_mcp_server.py
+++ b/workspace/a2a_mcp_server.py
@@ -35,12 +35,14 @@ from a2a_tools import (
     tool_commit_memory,
     tool_delegate_task,
     tool_delegate_task_async,
+    tool_get_runtime_identity,
     tool_get_workspace_info,
     tool_inbox_peek,
     tool_inbox_pop,
     tool_list_peers,
     tool_recall_memory,
     tool_send_message_to_user,
+    tool_update_agent_card,
     tool_wait_for_message,
 )
 from platform_tools.registry import TOOLS as _PLATFORM_TOOL_SPECS
@@ -130,6 +132,10 @@ async def handle_tool_call(name: str, arguments: dict) -> str:
         return await tool_get_workspace_info(
             source_workspace_id=arguments.get("source_workspace_id") or None,
         )
+    elif name == "get_runtime_identity":
+        return await tool_get_runtime_identity()
+    elif name == "update_agent_card":
+        return await tool_update_agent_card(arguments.get("card"))
     elif name == "commit_memory":
         return await tool_commit_memory(
             arguments.get("content", ""),
diff --git a/workspace/a2a_tools.py b/workspace/a2a_tools.py
index eb26e622f..b6c87e606 100644
--- a/workspace/a2a_tools.py
+++ b/workspace/a2a_tools.py
@@ -167,3 +167,15 @@ from a2a_tools_inbox import (  # noqa: E402  (import after the top-of-module imp
     tool_inbox_pop,
     tool_wait_for_message,
 )
+
+
+# Identity tool handlers — extracted to a2a_tools_identity. Ports the
+# two T4-tier MCP tools (``tool_get_runtime_identity`` +
+# ``tool_update_agent_card``) from molecule-ai-workspace-runtime PR#17.
+# That repo is mirror-only (reference_runtime_repo_is_mirror_only);
+# this is the canonical edit point, and the wheel mirror is
+# regenerated by publish-runtime.yml on merge.
+from a2a_tools_identity import (  # noqa: E402  (import after the top-of-module imports)
+    tool_get_runtime_identity,
+    tool_update_agent_card,
+)
diff --git a/workspace/a2a_tools_identity.py b/workspace/a2a_tools_identity.py
new file mode 100644
index 000000000..cec89ed00
--- /dev/null
+++ b/workspace/a2a_tools_identity.py
@@ -0,0 +1,187 @@
+"""Identity tool handlers — single-concern slice of the a2a_tools surface.
+
+Owns the two MCP tools that close the T4-tier workspace owner-permission
+gaps reported via the canvas:
+
+  * ``tool_get_runtime_identity`` — env-only; returns model, model_provider,
+    molecule_model, anthropic_base_url, tier, workspace_id, runtime
+    (ADAPTER_MODULE). No HTTP call. Always permitted by RBAC — even
+    read-only agents may know what model they are.
+
+  * ``tool_update_agent_card`` — POSTs the card to ``/registry/update-card``
+    with the workspace's own bearer (same auth path as ``tool_commit_memory``
+    via ``a2a_tools_rbac.auth_headers_for_heartbeat``). The platform
+    replaces the stored card and broadcasts an ``agent_card_updated``
+    event so the canvas reflects the new card live. Gated on
+    ``memory.write`` capability via the existing RBAC permission map so
+    read-only roles can't silently rewrite the platform card.
+
+Both originated as a port of molecule-ai-workspace-runtime PR#17
+(``feat(mcp): add update_agent_card + get_runtime_identity tools``).
+The mirror-only PR#17 was closed without merge per
+``reference_runtime_repo_is_mirror_only``; the canonical edit point is
+this monorepo at ``workspace/`` and the wheel mirror is regenerated
+automatically by the publish-runtime workflow.
+
+Imports the auth-header primitive from ``a2a_tools_rbac`` (iter 4a) —
+NOT from ``a2a_tools`` — to avoid a circular import with the
+kitchen-sink re-export module.
+"""
+from __future__ import annotations
+
+import json
+import os
+from typing import Any
+
+import httpx
+
+from a2a_client import PLATFORM_URL
+from a2a_tools_rbac import (
+    auth_headers_for_heartbeat as _auth_headers_for_heartbeat,
+    check_memory_write_permission as _check_memory_write_permission,
+)
+
+
+def _runtime_identity_payload() -> dict[str, Any]:
+    """Build the identity dict — env-only, no I/O.
+
+    Factored out from ``tool_get_runtime_identity`` so tests can assert
+    against the exact key set without re-parsing JSON. The MCP tool
+    handler ``tool_get_runtime_identity`` is the only public caller in
+    production; tests call this helper directly.
+    """
+    return {
+        "model": os.environ.get("MODEL", ""),
+        "model_provider": os.environ.get("MODEL_PROVIDER", ""),
+        "molecule_model": os.environ.get("MOLECULE_MODEL", ""),
+        "anthropic_base_url": os.environ.get("ANTHROPIC_BASE_URL", ""),
+        "tier": os.environ.get("TIER", ""),
+        "workspace_id": os.environ.get("WORKSPACE_ID", ""),
+        # Adapter module is the closest thing the runtime has to a
+        # "template slug" — e.g. "adapter" for claude-code-default,
+        # "hermes" for hermes-template, etc. Picked from
+        # $ADAPTER_MODULE env baked by each template's Dockerfile.
+        "runtime": os.environ.get("ADAPTER_MODULE", ""),
+    }
+
+
+async def tool_get_runtime_identity() -> str:
+    """Return this runtime's identity — model, provider, tier, IDs.
+
+    Env-only; no HTTP call. Useful so the agent can answer "what model
+    am I?" correctly instead of guessing from a stale system prompt
+    that the operator may have changed between boots.
+
+    Returns the identity as a JSON-encoded string (the dispatch contract
+    every MCP tool in this module follows). Tests that want to assert
+    individual fields can call ``_runtime_identity_payload()`` directly,
+    or ``json.loads`` the return value.
+
+    Always permitted by RBAC — there is no sensitive information here
+    that isn't already available to the process via ``os.environ``.
+    The point of the tool is to surface those env values to the agent
+    layer in a stable, documented shape rather than expecting every
+    agent runtime to know to ``echo $MODEL``.
+    """
+    return json.dumps(_runtime_identity_payload(), indent=2)
+
+
+async def tool_update_agent_card(card: Any) -> str:
+    """Update this workspace's agent_card on the platform.
+
+    POSTs the provided card to ``/registry/update-card`` with the
+    workspace's own bearer token (same auth path as ``tool_commit_memory``
+    and ``tool_get_workspace_info``). The platform validates required
+    fields server-side, replaces the stored card, and broadcasts an
+    ``agent_card_updated`` event so the canvas updates live.
+
+    Args:
+        card: A JSON-serialisable object (typically a dict) holding the
+            new card. The platform validates required fields server-side.
+
+    Returns:
+        JSON-encoded string. Body:
+          - ``{"success": true, "status": "updated"}`` on success;
+          - ``{"success": false, "error": "<msg>", "status_code": <int>}``
+            on platform error;
+          - ``{"success": false, "error": "<reason>"}`` on local validation
+            (non-dict card, missing WORKSPACE_ID, network error).
+
+    Permission gate: this tool requires the ``memory.write`` RBAC
+    capability — same gate as ``tool_commit_memory``. The check runs
+    inline rather than at the dispatcher layer to keep ``a2a_mcp_server``
+    permission-agnostic (the gate sits with the implementation, not the
+    transport). Read-only roles get a clear error string back instead
+    of a 403 from the platform.
+
+    We re-check ``isinstance(card, dict)`` here defensively rather than
+    trust the MCP schema validator alone — the schema only constrains
+    the transport, not the in-process call surface used by tests and
+    sibling modules.
+    """
+    payload = await _update_agent_card_impl(card)
+    return json.dumps(payload, indent=2)
+
+
+async def _update_agent_card_impl(card: Any) -> dict[str, Any]:
+    """Dict-returning core of ``tool_update_agent_card``.
+
+    Split out so tests can assert against the raw dict shape (status
+    codes, error messages) without re-parsing JSON on every assertion.
+    The string-returning ``tool_update_agent_card`` is a thin wrapper
+    invoked by the MCP dispatcher.
+    """
+    # RBAC: require memory.write permission. Same gate as
+    # tool_commit_memory (the agent already needs this capability to
+    # persist anything outbound). Read-only roles can still call
+    # get_runtime_identity / get_workspace_info to introspect — those
+    # are env-only / read-only and have no inline gate.
+    if not _check_memory_write_permission():
+        return {
+            "success": False,
+            "error": (
+                "RBAC — this workspace does not have the 'memory.write' "
+                "permission required to update the agent_card."
+            ),
+        }
+    if not isinstance(card, dict):
+        return {
+            "success": False,
+            "error": "card must be a JSON object (dict)",
+        }
+    ws_id = os.environ.get("WORKSPACE_ID", "")
+    if not ws_id:
+        return {
+            "success": False,
+            "error": "WORKSPACE_ID env not set; cannot identify caller",
+        }
+    try:
+        async with httpx.AsyncClient(timeout=10.0) as client:
+            resp = await client.post(
+                f"{PLATFORM_URL}/registry/update-card",
+                json={"workspace_id": ws_id, "agent_card": card},
+                headers=_auth_headers_for_heartbeat(),
+            )
+            if resp.status_code == 200:
+                body: dict[str, Any] = {}
+                try:
+                    body = resp.json()
+                except Exception:
+                    pass
+                return {
+                    "success": True,
+                    "status": body.get("status", "updated"),
+                }
+            # Non-200 — surface what the platform returned.
+            error_msg = ""
+            try:
+                error_msg = resp.json().get("error", "") or resp.text
+            except Exception:
+                error_msg = resp.text
+            return {
+                "success": False,
+                "status_code": resp.status_code,
+                "error": error_msg,
+            }
+    except Exception as e:
+        return {"success": False, "error": f"network error: {e}"}
diff --git a/workspace/executor_helpers.py b/workspace/executor_helpers.py
index aba334f9c..52ae41b46 100644
--- a/workspace/executor_helpers.py
+++ b/workspace/executor_helpers.py
@@ -340,6 +340,16 @@ _CLI_A2A_COMMAND_KEYWORDS: dict[str, str | None] = {
     "delegate_task_async": "delegate --async",
     "check_task_status": "status",
     "get_workspace_info": "info",
+    # `get_runtime_identity` + `update_agent_card` are MCP-first
+    # capabilities — the CLI subprocess interface doesn't expose them
+    # today. `get_runtime_identity` is env-only and an agent on a
+    # CLI-only runtime can already `echo $MODEL` etc, so there's no
+    # functional gap. `update_agent_card` requires a JSON object
+    # argument that wouldn't survive a positional-arg shell invocation
+    # cleanly. Mapped to None — flip to a keyword if a2a_cli grows
+    # `identity` / `card` subcommands in the future.
+    "get_runtime_identity": None,
+    "update_agent_card": None,
     # `broadcast_message` is not exposed via the CLI subprocess interface
     # today — it's an MCP-first capability. If a2a_cli grows a `broadcast`
     # subcommand, map it here and the alignment test will gate the change.
diff --git a/workspace/platform_tools/registry.py b/workspace/platform_tools/registry.py
index 6550c9e7d..c5b1f08e6 100644
--- a/workspace/platform_tools/registry.py
+++ b/workspace/platform_tools/registry.py
@@ -57,12 +57,14 @@ from a2a_tools import (
     tool_commit_memory,
     tool_delegate_task,
     tool_delegate_task_async,
+    tool_get_runtime_identity,
     tool_get_workspace_info,
     tool_inbox_peek,
     tool_inbox_pop,
     tool_list_peers,
     tool_recall_memory,
     tool_send_message_to_user,
+    tool_update_agent_card,
     tool_wait_for_message,
 )
 
@@ -289,6 +291,61 @@ _GET_WORKSPACE_INFO = ToolSpec(
     section=A2A_SECTION,
 )
 
+_GET_RUNTIME_IDENTITY = ToolSpec(
+    name="get_runtime_identity",
+    short=(
+        "Return this runtime's identity — model, model_provider, tier, "
+        "workspace_id, runtime template. Reads from process env; no HTTP call."
+    ),
+    when_to_use=(
+        "Use this to answer 'what model am I?' truthfully instead of "
+        "guessing from a stale system prompt — the operator may have "
+        "routed you to a different model via persona env between boots. "
+        "Always permitted by RBAC: even read-only agents may know what "
+        "model they are. Distinct from get_workspace_info — that one "
+        "calls the platform for ID/role/tier/parent (workspace metadata); "
+        "this one returns the live process env (MODEL, MODEL_PROVIDER, "
+        "MOLECULE_MODEL, ANTHROPIC_BASE_URL, TIER, WORKSPACE_ID, "
+        "ADAPTER_MODULE)."
+    ),
+    input_schema={"type": "object", "properties": {}},
+    impl=tool_get_runtime_identity,
+    section=A2A_SECTION,
+)
+
+_UPDATE_AGENT_CARD = ToolSpec(
+    name="update_agent_card",
+    short=(
+        "Replace this workspace's agent_card on the platform. The "
+        "platform validates required fields and broadcasts an "
+        "agent_card_updated event so the canvas reflects the change live."
+    ),
+    when_to_use=(
+        "Use when the workspace's capabilities, skills, description, or "
+        "name change and the canvas display needs to follow. The "
+        "platform stores the new card and pushes an "
+        "``agent_card_updated`` event to subscribers. Gated behind the "
+        "``memory.write`` RBAC capability — read-only roles cannot "
+        "rewrite the card. Tier-1+ owners always have this capability."
+    ),
+    input_schema={
+        "type": "object",
+        "properties": {
+            "card": {
+                "type": "object",
+                "description": (
+                    "The new agent_card object (name, version, "
+                    "description, skills, etc). Server-side validation "
+                    "rejects payloads missing required fields."
+                ),
+            },
+        },
+        "required": ["card"],
+    },
+    impl=tool_update_agent_card,
+    section=A2A_SECTION,
+)
+
 _BROADCAST_MESSAGE = ToolSpec(
     name="broadcast_message",
     short=(
@@ -642,6 +699,8 @@ TOOLS: list[ToolSpec] = [
     _CHECK_TASK_STATUS,
     _LIST_PEERS,
     _GET_WORKSPACE_INFO,
+    _GET_RUNTIME_IDENTITY,
+    _UPDATE_AGENT_CARD,
     _BROADCAST_MESSAGE,
     _SEND_MESSAGE_TO_USER,
     # Inbox (standalone-only; in-container returns informational error)
diff --git a/workspace/tests/snapshots/a2a_instructions_mcp.txt b/workspace/tests/snapshots/a2a_instructions_mcp.txt
index 3f0213e1b..92de32fa6 100644
--- a/workspace/tests/snapshots/a2a_instructions_mcp.txt
+++ b/workspace/tests/snapshots/a2a_instructions_mcp.txt
@@ -5,6 +5,8 @@
 - **check_task_status**: Poll the status of a task started with delegate_task_async; returns result when done.
 - **list_peers**: List the workspaces this agent can communicate with — name, ID, status, role for each.
 - **get_workspace_info**: Get this workspace's own info — ID, name, role, tier, parent, status.
+- **get_runtime_identity**: Return this runtime's identity — model, model_provider, tier, workspace_id, runtime template. Reads from process env; no HTTP call.
+- **update_agent_card**: Replace this workspace's agent_card on the platform. The platform validates required fields and broadcasts an agent_card_updated event so the canvas reflects the change live.
 - **broadcast_message**: Send a message to ALL agent workspaces in the org simultaneously. Requires broadcast_enabled=true on this workspace (set by user/admin).
 - **send_message_to_user**: Send a message directly to the user's canvas chat — pushed instantly via WebSocket. Use this to: (1) acknowledge a task immediately ('Got it, I'll start working on this'), (2) send interim progress updates while doing long work, (3) deliver follow-up results after delegation completes, (4) attach files (zip, pdf, csv, image) for the user to download via the `attachments` field (NEVER paste file URLs in `message`). The message appears in the user's chat as if you're proactively reaching out.
 - **wait_for_message**: Block until the next inbound message (canvas user OR peer agent) arrives, or until ``timeout_secs`` elapses.
@@ -27,6 +29,12 @@ Call this first when you need to delegate but don't know the target's ID. Access
 ### get_workspace_info
 Use to introspect your own identity (e.g. before reporting back to the user, or to determine whether you're a tier-0 root that can write GLOBAL memory).
 
+### get_runtime_identity
+Use this to answer 'what model am I?' truthfully instead of guessing from a stale system prompt — the operator may have routed you to a different model via persona env between boots. Always permitted by RBAC: even read-only agents may know what model they are. Distinct from get_workspace_info — that one calls the platform for ID/role/tier/parent (workspace metadata); this one returns the live process env (MODEL, MODEL_PROVIDER, MOLECULE_MODEL, ANTHROPIC_BASE_URL, TIER, WORKSPACE_ID, ADAPTER_MODULE).
+
+### update_agent_card
+Use when the workspace's capabilities, skills, description, or name change and the canvas display needs to follow. The platform stores the new card and pushes an ``agent_card_updated`` event to subscribers. Gated behind the ``memory.write`` RBAC capability — read-only roles cannot rewrite the card. Tier-1+ owners always have this capability.
+
 ### broadcast_message
 Use for urgent, org-wide signals: critical status changes, emergency stop instructions, coordinated task announcements. Every non-removed workspace receives the message in its activity log (poll-mode agents see it on their next poll; push-mode canvases get a real-time banner). This tool returns an error if broadcast_enabled is false — a user or admin must enable it via the workspace abilities settings first.
 
diff --git a/workspace/tests/test_a2a_tools_identity.py b/workspace/tests/test_a2a_tools_identity.py
new file mode 100644
index 000000000..ca8b4dc11
--- /dev/null
+++ b/workspace/tests/test_a2a_tools_identity.py
@@ -0,0 +1,390 @@
+"""Tests for ``tool_get_runtime_identity`` and ``tool_update_agent_card``.
+
+These two MCP tools close the T4-tier workspace owner-permission gaps
+reported via the canvas:
+
+  - the agent could not update its own ``agent_card`` (no MCP tool
+    wrapped the existing ``POST /registry/update-card`` endpoint);
+  - the agent could not identify which model it was running (the
+    ``MODEL`` env var is injected by ``provisioner.workspace_provision``
+    but nothing surfaced it back to the agent).
+
+Ported from molecule-ai-workspace-runtime PR#17 (mirror-only repo;
+canonical edit point per ``reference_runtime_repo_is_mirror_only``).
+Adapted to core's conventions:
+
+  * tool functions return ``str`` (JSON-encoded), matching every other
+    tool in ``a2a_tools_*`` modules. Tests ``json.loads`` to inspect.
+  * permission check ``memory.write`` runs inline in
+    ``tool_update_agent_card`` (same pattern as
+    ``a2a_tools_memory.tool_commit_memory``).
+  * ``WORKSPACE_ID`` is read directly from ``os.environ`` — core does
+    not have the runtime's validated-cache layer (``molecule_runtime.
+    builtin_tools.validation``).
+"""
+from __future__ import annotations
+
+import json
+
+import pytest
+
+
+# --- Drift gate: re-export aliases on a2a_tools ------------------------------
+
+class TestBackCompatAliases:
+    """Pin that ``a2a_tools.tool_*`` resolves to the same callable as
+    ``a2a_tools_identity.tool_*``. Refactor wrapping (e.g. a doc-string
+    wrapper that loses the function identity) silently breaks call
+    sites that ``patch("a2a_tools.tool_update_agent_card", ...)`` —
+    this gate makes that drift fail fast."""
+
+    def test_tool_get_runtime_identity_alias(self):
+        import a2a_tools
+        import a2a_tools_identity
+        assert a2a_tools.tool_get_runtime_identity is a2a_tools_identity.tool_get_runtime_identity
+
+    def test_tool_update_agent_card_alias(self):
+        import a2a_tools
+        import a2a_tools_identity
+        assert a2a_tools.tool_update_agent_card is a2a_tools_identity.tool_update_agent_card
+
+
+# --- tool_get_runtime_identity ----------------------------------------------
+
+class TestGetRuntimeIdentity:
+    """The tool returns env-derived runtime identity. No HTTP call."""
+
+    @pytest.mark.asyncio
+    async def test_returns_all_known_env_fields(self, monkeypatch):
+        from a2a_tools_identity import tool_get_runtime_identity
+
+        monkeypatch.setenv("MODEL", "claude-opus-4-7")
+        monkeypatch.setenv("MODEL_PROVIDER", "anthropic")
+        monkeypatch.setenv("TIER", "T4")
+        monkeypatch.setenv("WORKSPACE_ID", "ws-abc")
+        monkeypatch.setenv("ADAPTER_MODULE", "adapter")
+        monkeypatch.setenv("MOLECULE_MODEL", "claude-opus-4-7")
+        monkeypatch.setenv("ANTHROPIC_BASE_URL", "https://api.anthropic.com")
+
+        out = await tool_get_runtime_identity()
+        # MCP tools return JSON-encoded strings (matches the contract
+        # every other tool_* in a2a_tools_* uses).
+        assert isinstance(out, str)
+        parsed = json.loads(out)
+
+        assert parsed["model"] == "claude-opus-4-7"
+        assert parsed["model_provider"] == "anthropic"
+        assert parsed["tier"] == "T4"
+        assert parsed["workspace_id"] == "ws-abc"
+        assert parsed["runtime"] == "adapter"
+        assert parsed["molecule_model"] == "claude-opus-4-7"
+        assert parsed["anthropic_base_url"] == "https://api.anthropic.com"
+
+    @pytest.mark.asyncio
+    async def test_missing_env_returns_empty_strings(self, monkeypatch):
+        """Tool MUST NOT raise when env vars are absent — every key is
+        present but the value is the empty string. The agent then knows
+        the slot exists but is unset."""
+        from a2a_tools_identity import tool_get_runtime_identity
+
+        for var in (
+            "MODEL", "MODEL_PROVIDER", "TIER", "WORKSPACE_ID",
+            "ADAPTER_MODULE", "MOLECULE_MODEL", "ANTHROPIC_BASE_URL",
+        ):
+            monkeypatch.delenv(var, raising=False)
+
+        parsed = json.loads(await tool_get_runtime_identity())
+        assert parsed["model"] == ""
+        assert parsed["model_provider"] == ""
+        assert parsed["tier"] == ""
+        assert parsed["workspace_id"] == ""
+        assert parsed["runtime"] == ""
+        assert parsed["molecule_model"] == ""
+        assert parsed["anthropic_base_url"] == ""
+
+    @pytest.mark.asyncio
+    async def test_no_http_call_made(self, monkeypatch):
+        """``get_runtime_identity`` is env-only — must not open
+        httpx.AsyncClient even if the call would otherwise succeed.
+        Tripwire any client construction."""
+        import httpx
+
+        from a2a_tools_identity import tool_get_runtime_identity
+
+        class _Tripwire:
+            def __init__(self, *_a, **_kw):
+                raise AssertionError(
+                    "tool_get_runtime_identity must not open httpx.AsyncClient"
+                )
+
+        monkeypatch.setattr(httpx, "AsyncClient", _Tripwire)
+        # Must not raise.
+        await tool_get_runtime_identity()
+
+    @pytest.mark.asyncio
+    async def test_helper_dict_matches_string_payload(self, monkeypatch):
+        """``_runtime_identity_payload`` is the dict-returning helper
+        used by both the public tool and tests. Verify the public tool
+        json.dumps the same dict — no field is dropped or renamed by
+        the encoding step."""
+        from a2a_tools_identity import (
+            _runtime_identity_payload,
+            tool_get_runtime_identity,
+        )
+
+        monkeypatch.setenv("MODEL", "claude-opus-4-7")
+        monkeypatch.setenv("TIER", "T4")
+        monkeypatch.setenv("WORKSPACE_ID", "ws-helper-check")
+
+        helper = _runtime_identity_payload()
+        tool_str = await tool_get_runtime_identity()
+        assert json.loads(tool_str) == helper
+
+
+# --- tool_update_agent_card -------------------------------------------------
+
+
+class _MockResponse:
+    def __init__(self, status_code: int, payload: dict):
+        self.status_code = status_code
+        self._payload = payload
+        self.text = json.dumps(payload)
+
+    def json(self):
+        return self._payload
+
+
+class _MockClient:
+    """Drop-in for httpx.AsyncClient context manager.
+
+    Records the URL + json body + headers the tool POSTed so the test
+    can assert against them. Returns the canned _MockResponse passed
+    in at construction time.
+    """
+
+    def __init__(self, *, response: _MockResponse, captured: dict):
+        self._response = response
+        self._captured = captured
+
+    async def __aenter__(self):
+        return self
+
+    async def __aexit__(self, *_args):
+        return False
+
+    async def post(self, url, *, json=None, headers=None, **_kw):  # noqa: A002
+        self._captured["url"] = url
+        self._captured["json"] = json
+        self._captured["headers"] = headers
+        return self._response
+
+
+@pytest.fixture
+def _grant_memory_write(monkeypatch):
+    """Force the inline RBAC gate inside ``tool_update_agent_card`` to
+    succeed. The gate calls
+    ``a2a_tools_rbac.check_memory_write_permission`` which inspects
+    ``$MOLECULE_ROLES`` / the role table; the patch sidesteps that
+    machinery so tests can focus on the platform-call shape.
+    """
+    import a2a_tools_identity
+    monkeypatch.setattr(
+        a2a_tools_identity, "_check_memory_write_permission", lambda: True
+    )
+
+
+class TestUpdateAgentCard:
+    @pytest.mark.asyncio
+    async def test_posts_to_registry_update_card(
+        self, monkeypatch, _grant_memory_write,
+    ):
+        """Hits POST {PLATFORM_URL}/registry/update-card with the
+        workspace bearer and the {workspace_id, agent_card} body shape
+        the platform handler expects (workspace-server
+        ``internal/handlers/registry.go``)."""
+        import a2a_tools_identity
+
+        monkeypatch.setenv("WORKSPACE_ID", "ws-42")
+        # Ensure PLATFORM_URL re-import sees a deterministic value —
+        # a2a_client imports it at module load so we patch the symbol
+        # on a2a_tools_identity directly (the module's own reference).
+        monkeypatch.setattr(a2a_tools_identity, "PLATFORM_URL", "http://test.invalid")
+
+        captured: dict = {}
+        response = _MockResponse(200, {"status": "updated"})
+
+        def _client_factory(*_a, **_kw):
+            return _MockClient(response=response, captured=captured)
+
+        monkeypatch.setattr(a2a_tools_identity.httpx, "AsyncClient", _client_factory)
+        monkeypatch.setattr(
+            a2a_tools_identity, "_auth_headers_for_heartbeat",
+            lambda: {"Authorization": "Bearer ws-token-xyz"},
+        )
+
+        card = {"name": "agent-foo", "version": "0.1.0", "description": "demo"}
+        result_str = await a2a_tools_identity.tool_update_agent_card(card)
+        result = json.loads(result_str)
+
+        # URL: PLATFORM_URL + /registry/update-card
+        assert captured["url"] == "http://test.invalid/registry/update-card"
+
+        # The platform handler expects {workspace_id, agent_card}; the
+        # agent_card is the raw object the agent submitted.
+        body = captured["json"]
+        assert body["workspace_id"] == "ws-42"
+        assert body["agent_card"] == card
+
+        # Auth header from auth_headers_for_heartbeat is forwarded
+        # verbatim — same path commit_memory uses.
+        assert captured["headers"]["Authorization"] == "Bearer ws-token-xyz"
+
+        assert result["success"] is True
+        assert result["status"] == "updated"
+
+    @pytest.mark.asyncio
+    async def test_propagates_server_error(
+        self, monkeypatch, _grant_memory_write,
+    ):
+        """Non-200 from platform surfaces as a structured error to the
+        agent. The agent sees {success:false, status_code, error} and
+        can decide whether to retry, fall back, or escalate."""
+        import a2a_tools_identity
+
+        monkeypatch.setenv("WORKSPACE_ID", "ws-42")
+        monkeypatch.setattr(a2a_tools_identity, "PLATFORM_URL", "http://test.invalid")
+
+        captured: dict = {}
+        response = _MockResponse(400, {"error": "invalid card"})
+
+        monkeypatch.setattr(
+            a2a_tools_identity.httpx, "AsyncClient",
+            lambda *a, **kw: _MockClient(response=response, captured=captured),
+        )
+        monkeypatch.setattr(
+            a2a_tools_identity, "_auth_headers_for_heartbeat", lambda: {},
+        )
+
+        result = json.loads(
+            await a2a_tools_identity.tool_update_agent_card({"name": "x"})
+        )
+        assert result["success"] is False
+        assert result["status_code"] == 400
+        assert "invalid card" in str(result["error"]).lower()
+
+    @pytest.mark.asyncio
+    async def test_rejects_non_dict_card(self, _grant_memory_write):
+        """The MCP schema constrains transport callers to pass a dict;
+        in-process callers (tests, sibling modules) can still pass any
+        type. Reject non-dict defensively so the platform isn't asked
+        to validate JSON-encoded strings or lists."""
+        from a2a_tools_identity import tool_update_agent_card
+
+        result = json.loads(await tool_update_agent_card("not-a-dict"))
+        assert result["success"] is False
+        assert "dict" in str(result["error"]).lower()
+
+    @pytest.mark.asyncio
+    async def test_workspace_id_missing_returns_error(
+        self, monkeypatch, _grant_memory_write,
+    ):
+        """If WORKSPACE_ID is not set the tool refuses to issue the
+        request — it would otherwise POST with an empty workspace_id
+        and let the platform return a confusing 400."""
+        from a2a_tools_identity import tool_update_agent_card
+
+        monkeypatch.delenv("WORKSPACE_ID", raising=False)
+
+        result = json.loads(await tool_update_agent_card({"name": "x"}))
+        assert result["success"] is False
+        assert "workspace_id" in str(result["error"]).lower()
+
+    @pytest.mark.asyncio
+    async def test_denies_when_memory_write_permission_missing(self, monkeypatch):
+        """The agent's RBAC role must grant ``memory.write`` to update
+        the card. Read-only roles get an RBAC error string back
+        immediately, never touching the platform."""
+        import a2a_tools_identity
+
+        monkeypatch.setenv("WORKSPACE_ID", "ws-42")
+        monkeypatch.setattr(
+            a2a_tools_identity, "_check_memory_write_permission", lambda: False,
+        )
+
+        # Tripwire httpx — must not be called when RBAC denies.
+        import httpx
+
+        class _Tripwire:
+            def __init__(self, *_a, **_kw):
+                raise AssertionError("RBAC denial must short-circuit before httpx call")
+
+        monkeypatch.setattr(httpx, "AsyncClient", _Tripwire)
+
+        result = json.loads(
+            await a2a_tools_identity.tool_update_agent_card({"name": "x"}),
+        )
+        assert result["success"] is False
+        assert "memory.write" in str(result["error"]).lower()
+
+    @pytest.mark.asyncio
+    async def test_network_exception_returns_structured_error(
+        self, monkeypatch, _grant_memory_write,
+    ):
+        """A network exception (DNS failure, connect timeout, etc) is
+        wrapped into a structured error dict instead of bubbling up
+        to the MCP transport layer."""
+        import a2a_tools_identity
+
+        monkeypatch.setenv("WORKSPACE_ID", "ws-42")
+        monkeypatch.setattr(a2a_tools_identity, "PLATFORM_URL", "http://test.invalid")
+
+        class _ExplodingClient:
+            async def __aenter__(self):
+                return self
+
+            async def __aexit__(self, *_a):
+                return False
+
+            async def post(self, *_a, **_kw):
+                raise RuntimeError("simulated DNS failure")
+
+        monkeypatch.setattr(
+            a2a_tools_identity.httpx, "AsyncClient",
+            lambda *a, **kw: _ExplodingClient(),
+        )
+
+        result = json.loads(
+            await a2a_tools_identity.tool_update_agent_card({"name": "x"})
+        )
+        assert result["success"] is False
+        assert "network" in str(result["error"]).lower()
+
+
+# --- Registry contract ------------------------------------------------------
+
+
+class TestRegistryContract:
+    """Pin the new tools' registration in platform_tools.registry. The
+    structural tests in ``test_platform_tools.py`` already check
+    registry↔MCP alignment; these are tighter assertions specific to
+    the two new tools so a future contributor deleting one entry sees
+    a focused failure."""
+
+    def test_get_runtime_identity_in_registry(self):
+        from platform_tools.registry import by_name
+        spec = by_name("get_runtime_identity")
+        assert spec.section == "a2a"
+        # No input parameters — env-only call.
+        assert spec.input_schema == {"type": "object", "properties": {}}
+        # impl points at the actual tool function, not a shim.
+        from a2a_tools_identity import tool_get_runtime_identity
+        assert spec.impl is tool_get_runtime_identity
+
+    def test_update_agent_card_in_registry(self):
+        from platform_tools.registry import by_name
+        spec = by_name("update_agent_card")
+        assert spec.section == "a2a"
+        assert "card" in spec.input_schema["properties"]
+        assert spec.input_schema["required"] == ["card"]
+        from a2a_tools_identity import tool_update_agent_card
+        assert spec.impl is tool_update_agent_card