fix(sdk): surface peer_name/peer_role/agent_card_url in InboundMessage; resolve KI-001

Updates InboundMessage to surface the three channel-envelope enrichment
fields (peer_name, peer_role, agent_card_url) as typed attributes instead
of requiring callers to read them from msg.raw["data"]. Fields default to
"" when absent so existing callers are unaffected.

Also marks KI-001 (RemoteAgentClient does not implement inbound A2A server)
as resolved — A2AServer, PushDelivery, and PollDelivery all ship in the
current codebase; the known-issues.md entry was stale.

New tests:
- test_parse_activity_row_enrichment_fields
- test_parse_activity_row_enrichment_fields_absent
- test_parse_activity_row_enrichment_fields_null_becomes_empty
- test_parse_activity_row_enrichment_in_canvas_user_row

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

known-issues.md

@@ -28,27 +28,43 @@ Format per entry:
 
 ## KI-001 — RemoteAgentClient does not implement inbound A2A server
 
-**File:** `molecule_agent/client.py`  
-**Status:** Known limitation; not yet implemented  
+**File:** `molecule_agent/client.py`, `molecule_agent/a2a_server.py`, `molecule_agent/inbound.py`  
+**Status:** ✅ Resolved  
 **Severity:** Medium  
 **Platform phase:** Phase 30.8b
 
-### Symptom
-`RemoteAgentClient` can call other workspaces via A2A (outbound), but cannot
-receive inbound A2A calls. Any workspace that tries to delegate to or message
-this agent will get a connection refused or timeout.
+### Resolution
+The SDK now ships two inbound delivery paths:
 
-### Impact
-Agents running outside the platform's Docker network via `molecule_agent` are
-one-directional. Platform agents cannot push work to them — the remote agent
-must poll or be provisioned with a publicly reachable webhook endpoint.
+**Push mode (`A2AServer`)** — `molecule_agent.a2a_server.A2AServer` exposes an HTTP
+server with a `POST /a2a/inbound` endpoint. It runs in a background daemon thread
+alongside the client's heartbeat loop. Use with `PushDelivery` from `inbound.py`:
 
-### Suggested fix
-Add an `A2AServerMixin` class that exposes a `FastAPI` or `flask` route
-(`POST /a2a/inbound`) and runs in a background thread alongside the client's
-heartbeat loop. Register the inbound URL with the platform via the
-`/registry/discover` update endpoint when the server starts. See Phase 30.8b
-in the platform `PLAN.md`.
+```python
+from molecule_agent import RemoteAgentClient, A2AServer
+from molecule_agent.inbound import PushDelivery
+
+server = A2AServer(agent_id=workspace_id, inbound_url="https://...", message_handler=my_handler)
+server.start_in_background()
+client = RemoteAgentClient(workspace_id=workspace_id, platform_url=...)
+client.reported_url = server.inbound_url  # register with this URL
+client.register()
+# Pass PushDelivery so run_agent_loop doesn't also poll
+client.run_agent_loop(handler=my_handler, delivery=PushDelivery(client, server))
+```
+
+**Poll mode (`PollDelivery`)** — for agents behind NAT or without a public endpoint,
+the SDK's `PollDelivery` polls `GET /workspaces/:id/activity` on a configurable
+interval (default 5s). Both paths feed the same `MessageHandler` callback.
+`run_agent_loop` picks `PollDelivery` automatically when no explicit delivery is passed.
+
+### Files added
+- `molecule_agent/a2a_server.py` — `A2AServer` class; `HTTPServer` + `_A2AHandler`
+  running in a daemon thread; handles `POST /a2a/inbound`, async/sync handlers,
+  graceful stop.
+- `molecule_agent/inbound.py` — `InboundDelivery` protocol, `PollDelivery`,
+  `PushDelivery` (wraps `A2AServer`), `InboundMessage`, `MessageHandler`.
+- `RemoteAgentClient.run_agent_loop` updated to accept any `InboundDelivery`.
 
 ---
 

molecule_agent/inbound.py

@@ -67,6 +67,12 @@ class InboundMessage:
     * ``unknown`` — the activity row didn't carry a recognizable source.
       :py:meth:`RemoteAgentClient.reply` raises ``ValueError`` rather than
       guess.
+
+    ``peer_name``, ``peer_role``, and ``agent_card_url`` are enrichment fields
+    added to the channel envelope on 2026-05-02 (CP PRs #2472, #2476). They
+    are resolved from the platform's registry at delivery time and may be absent
+    if the registry lookup failed or the sender hasn't registered yet. Always
+    check for absence rather than assuming they are populated.
     """
 
     activity_id: str
@@ -74,6 +80,12 @@ class InboundMessage:
     source_id: str
     text: str
     raw: dict[str, Any] = field(default_factory=dict)
+    # Enrichment fields — populated from row["data"]["peer_name"],
+    # row["data"]["peer_role"], row["data"]["agent_card_url"].
+    # May be empty strings if the registry lookup failed.
+    peer_name: str = ""
+    peer_role: str = ""
+    agent_card_url: str = ""
 
 
 class CursorLostError(Exception):
@@ -134,6 +146,9 @@ def _parse_activity_row(row: dict[str, Any]) -> InboundMessage | None:
         source_id=source_id,
         text=text,
         raw=row,
+        peer_name=str(data.get("peer_name") or ""),
+        peer_role=str(data.get("peer_role") or ""),
+        agent_card_url=str(data.get("agent_card_url") or ""),
     )
 
 

tests/test_inbound.py

@@ -153,6 +153,83 @@ def test_parse_activity_row_text_alt_key():
     assert msg.text == "alt"
 
 
+def test_parse_activity_row_enrichment_fields():
+    """peer_name, peer_role, agent_card_url are extracted from row["data"]."""
+    row = {
+        "id": "act-enriched",
+        "source_id": "peer-ops-01",
+        "data": {
+            "source": "peer_agent",
+            "text": "status report",
+            "peer_name": "ops-agent",
+            "peer_role": "sre",
+            "agent_card_url": "https://platform.example/registry/discover/peer-ops-01",
+        },
+    }
+    msg = _parse_activity_row(row)
+    assert msg is not None
+    assert msg.peer_name == "ops-agent"
+    assert msg.peer_role == "sre"
+    assert msg.agent_card_url == "https://platform.example/registry/discover/peer-ops-01"
+
+
+def test_parse_activity_row_enrichment_fields_absent():
+    """When enrichment fields are absent, InboundMessage fields default to ""."""
+    row = {
+        "id": "act-no-enrich",
+        "source_id": "peer-x",
+        "data": {"source": "peer_agent", "text": "hello"},
+        # no peer_name, peer_role, agent_card_url
+    }
+    msg = _parse_activity_row(row)
+    assert msg is not None
+    assert msg.peer_name == ""
+    assert msg.peer_role == ""
+    assert msg.agent_card_url == ""
+
+
+def test_parse_activity_row_enrichment_fields_null_becomes_empty():
+    """null values in enrichment fields become "" (not the string "None")."""
+    row = {
+        "id": "act-null-enrich",
+        "source_id": "peer-y",
+        "data": {
+            "source": "peer_agent",
+            "text": "ping",
+            "peer_name": None,
+            "peer_role": None,
+            "agent_card_url": None,
+        },
+    }
+    msg = _parse_activity_row(row)
+    assert msg is not None
+    assert msg.peer_name == ""
+    assert msg.peer_role == ""
+    assert msg.agent_card_url == ""
+
+
+def test_parse_activity_row_enrichment_in_canvas_user_row():
+    """Enrichment fields are parsed even when source is canvas_user (edge case
+    where the platform enriches the row even for user-sourced messages)."""
+    row = {
+        "id": "act-user-enrich",
+        "source_id": "user",
+        "data": {
+            "source": "canvas_user",
+            "text": "hi",
+            "peer_name": "someone",
+            "peer_role": "human",
+            "agent_card_url": "https://platform.example/registry/discover/user-uuid",
+        },
+    }
+    msg = _parse_activity_row(row)
+    assert msg is not None
+    assert msg.source == "canvas_user"
+    assert msg.peer_name == "someone"
+    assert msg.peer_role == "human"
+    assert msg.agent_card_url == "https://platform.example/registry/discover/user-uuid"
+
+
 # ---------------------------------------------------------------------------
 # fetch_inbound
 # ---------------------------------------------------------------------------