feat: restore WORKSPACE_ROOT, add fastmcp server (App over SQLiteStore)

pyproject.toml

@@ -7,7 +7,9 @@ authors = [
     { name = "lda", email = "[email protected]" }
 ]
 requires-python = ">=3.14"
-dependencies = []
+dependencies = [
+    "fastmcp>=4.0.0",
+]
 
 [tool.uv]
 package = true

src/agentmsgs/mcp/server.py

@@ -0,0 +1,102 @@
+from __future__ import annotations
+
+from fastmcp import FastMCP
+
+from agentmsgs.core.app import App
+from agentmsgs.stores.sqlite import SQLiteStore
+from agentmsgs.utils import WORKSPACE_ROOT
+
+mcp = FastMCP("agentmsgs")
+
+# Shared App — file-backed so opencode ↔ codex share the same DB even as separate processes
+_app = App(store=SQLiteStore(WORKSPACE_ROOT / ".agentmsgs.db"))
+
+
+@mcp.tool
+def create_agent(name: str) -> dict:
+    """Create or get an ephemeral agent (id is key, name soft-unique)."""
+    agent = _app.get_or_create_agent(name)
+    return {"id": str(agent.id), "name": agent.name}
+
+
+@mcp.tool
+def delete_account(agent_id: str) -> dict:
+    """Delete an agent by id."""
+    from uuid import UUID
+
+    _app.delete_account(UUID(agent_id))
+    return {"deleted": agent_id}
+
+
+@mcp.tool
+def create_thread(participant_names: list[str]) -> dict:
+    """Create a thread with 2+ agents by name."""
+    agents = [_app.get_or_create_agent(n) for n in participant_names]
+    thread = _app.create_thread(*agents)
+    return {
+        "id": str(thread.id),
+        "participants": [
+            {"id": str(a.id), "name": a.name} for a in thread.participants
+        ],
+    }
+
+
+@mcp.tool
+def join_thread(thread_id: str, agent_name: str) -> dict:
+    """Add an agent to an existing thread."""
+    from uuid import UUID
+
+    agent = _app.get_or_create_agent(agent_name)
+    thread = _app.join_thread(UUID(thread_id), agent)
+    return {"id": str(thread.id), "participants": [a.name for a in thread.participants]}
+
+
+@mcp.tool
+def append(thread_id: str, sender_name: str, content: str) -> dict:
+    """Append a message to a thread."""
+    from uuid import UUID
+
+    sender = _app.get_or_create_agent(sender_name)
+    msg = _app.append(UUID(thread_id), sender, content)
+    return {
+        "id": str(msg.id),
+        "seq": msg.seq,
+        "sender": sender.name,
+        "content": msg.content,
+    }
+
+
+@mcp.tool
+def poll(thread_id: str, after_seq: int = 0) -> list[dict]:
+    """Poll messages in a thread after seq."""
+    from uuid import UUID
+
+    # poll doesn't need agent for cursor; use raw store list for simplicity
+    msgs = _app.poll(UUID(thread_id), _app.get_or_create_agent("__poll__"), after_seq)
+    # filter out the dummy poll agent if it ever sent (it never does)
+    return [
+        {
+            "seq": m.seq,
+            "sender": m.sender.name,
+            "content": m.content,
+            "ts": m.ts.isoformat(),
+        }
+        for m in msgs
+    ]
+
+
+@mcp.tool
+def has_unread(thread_id: str, agent_name: str) -> dict:
+    """Check if agent has unread messages in thread."""
+    from uuid import UUID
+
+    agent = _app.get_or_create_agent(agent_name)
+    return {"has_unread": _app.has_unread(UUID(thread_id), agent)}
+
+
+def main() -> None:
+    mcp.run()
+
+
+if __name__ == "__main__":
+    main()

src/agentmsgs/utils.py

@@ -0,0 +1,6 @@
+from pathlib import Path
+
+WORKSPACE_ROOT = Path(__file__).parent.parent.parent
+assert WORKSPACE_ROOT / "src" / "agentmsgs" / "utils.py" == Path(__file__), (
+    "this file should be located at src/agentmsgs/utils.py"
+)