diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a7474110..601533f4 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -175,6 +175,17 @@ and run CI manually.
 - Type hints on public functions
 - pytest for all tests
 
+## External integrations
+
+Code in this repo lands in molecule-core. Some related runtime artifacts
+live in their own repos:
+
+- [`Molecule-AI/molecule-ai-workspace-runtime`](https://github.com/Molecule-AI/molecule-ai-workspace-runtime) — Python adapter SDK (`molecule_runtime`) that runs inside containerized Molecule workspaces. Bridges Claude Code SDK / hermes / langgraph / etc. → A2A queue.
+- [`Molecule-AI/molecule-sdk-python`](https://github.com/Molecule-AI/molecule-sdk-python) — `A2AServer` + `RemoteAgentClient` for external agents that register over the public `/registry/register` flow.
+- [`Molecule-AI/molecule-mcp-claude-channel`](https://github.com/Molecule-AI/molecule-mcp-claude-channel) — Claude Code channel plugin. Bridges A2A traffic into a running Claude Code session via MCP `notifications/claude/channel`. Polling-based (no tunnel required); install with `claude --channels plugin:molecule@Molecule-AI/molecule-mcp-claude-channel`.
+
+When extending the **A2A surface** in molecule-core (`workspace-server/internal/handlers/a2a_proxy.go` etc.), consider whether the change has a downstream impact on the runtime SDK or the channel plugin — they're versioned independently but share the wire shape.
+
 ## Architecture Overview
 
 See `CLAUDE.md` for detailed architecture documentation, including:
diff --git a/workspace-server/internal/handlers/external_connection.go b/workspace-server/internal/handlers/external_connection.go
index 7a73a37b..12a3abfb 100644
--- a/workspace-server/internal/handlers/external_connection.go
+++ b/workspace-server/internal/handlers/external_connection.go
@@ -67,6 +67,37 @@ curl -fsS -X POST "{{PLATFORM_URL}}/registry/register" \
   }'
 `
 
+// externalChannelTemplate — Claude Code channel plugin install + .env. For
+// operators whose external agent IS a Claude Code session (laptop or
+// remote dev VM); routes the workspace's A2A traffic into the running
+// Claude Code session as conversation turns via MCP. The plugin source
+// lives at github.com/Molecule-AI/molecule-mcp-claude-channel — polling
+// based, no tunnel required (uses /workspaces/:id/activity?since_secs=,
+// platform-side support shipped in #2300).
+const externalChannelTemplate = `# Claude Code channel — bridges this workspace's A2A traffic into your
+# Claude Code session. No tunnel/public URL needed (polling-based).
+#
+# 1. Save this token + workspace_id, then create ~/.claude/channels/molecule/.env:
+mkdir -p ~/.claude/channels/molecule
+cat > ~/.claude/channels/molecule/.env <<'EOF'
+MOLECULE_PLATFORM_URL={{PLATFORM_URL}}
+MOLECULE_WORKSPACE_IDS={{WORKSPACE_ID}}
+MOLECULE_WORKSPACE_TOKENS=<paste auth_token from create response>
+EOF
+chmod 600 ~/.claude/channels/molecule/.env
+
+# 2. Launch Claude Code with the channel enabled:
+claude --channels plugin:molecule@Molecule-AI/molecule-mcp-claude-channel
+
+# Inbound A2A messages now surface as conversation turns. Claude's
+# replies route back via the reply_to_workspace MCP tool — no extra
+# wiring on your side.
+#
+# Multi-workspace: comma-separate IDs and tokens (same order). See
+# https://github.com/Molecule-AI/molecule-mcp-claude-channel for
+# pairing flow, push-mode upgrade, and v0.2 roadmap.
+`
+
 // externalPythonTemplate uses molecule-sdk-python's RemoteAgentClient +
 // A2AServer (PR #13 in that repo). Until the SDK cuts a v0.y release
 // to PyPI the snippet pins git+main.
diff --git a/workspace-server/internal/handlers/workspace.go b/workspace-server/internal/handlers/workspace.go
index 723b85b6..00d86b7e 100644
--- a/workspace-server/internal/handlers/workspace.go
+++ b/workspace-server/internal/handlers/workspace.go
@@ -370,6 +370,17 @@ func (h *WorkspaceHandler) Create(c *gin.Context) {
 						"{{PLATFORM_URL}}", platformURL),
 					"{{WORKSPACE_ID}}", id,
 				),
+				// Claude Code channel plugin snippet. For operators
+				// whose external agent IS a Claude Code session —
+				// the snippet sets up ~/.claude/channels/molecule/.env
+				// and points at the canonical first-party plugin at
+				// github.com/Molecule-AI/molecule-mcp-claude-channel.
+				// Polling-based; no tunnel needed.
+				"claude_code_channel_snippet": strings.ReplaceAll(
+					strings.ReplaceAll(externalChannelTemplate,
+						"{{PLATFORM_URL}}", platformURL),
+					"{{WORKSPACE_ID}}", id,
+				),
 			}
 		}
 		c.JSON(http.StatusCreated, resp)