agent-runtime/agent/mcp_app.py

"""Standalone MCP SSE app — proxies tool calls to cog-runtime."""

import json
import logging
import os
from pathlib import Path

from dotenv import load_dotenv
load_dotenv(Path(__file__).parent.parent / ".env")

import httpx
from fastapi import FastAPI, Request, Depends
from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer

from mcp.server import Server
from mcp.server.sse import SseServerTransport
from mcp.types import TextContent, Tool

logging.basicConfig(level=logging.INFO, format="%(asctime)s [%(name)s] %(message)s", datefmt="%H:%M:%S")
log = logging.getLogger("mcp-proxy")

# Config
RUNTIME_URL = os.environ.get("RUNTIME_URL", "http://cog-runtime")
SERVICE_TOKENS = set(filter(None, os.environ.get("SERVICE_TOKENS", "").split(",")))
SERVICE_TOKEN = os.environ.get("SERVICE_TOKENS", "").split(",")[0] if os.environ.get("SERVICE_TOKENS") else ""

app = FastAPI(title="cog-mcp")
_security = HTTPBearer()


async def require_auth(creds: HTTPAuthorizationCredentials = Depends(_security)):
    if creds.credentials not in SERVICE_TOKENS:
        from fastapi import HTTPException
        raise HTTPException(status_code=401, detail="Invalid token")
    return {"sub": "service", "source": "service_token"}


@app.get("/health")
async def health():
    return {"status": "ok", "service": "mcp-proxy"}


# --- MCP Server ---

mcp_server = Server("cog")
_mcp_transport = SseServerTransport("/mcp/messages/")


async def _proxy_get(path: str, params: dict = None) -> dict:
    """GET request to runtime."""
    try:
        async with httpx.AsyncClient(timeout=30) as client:
            resp = await client.get(
                f"{RUNTIME_URL}{path}",
                params=params,
                headers={"Authorization": f"Bearer {SERVICE_TOKEN}"},
            )
            if resp.status_code == 200:
                return resp.json()
            try:
                return {"error": resp.json().get("detail", resp.text)}
            except Exception:
                return {"error": resp.text}
    except Exception as e:
        return {"error": f"Runtime unreachable: {e}"}


async def _proxy_post(path: str, body: dict = None) -> dict:
    """POST request to runtime."""
    try:
        async with httpx.AsyncClient(timeout=30) as client:
            resp = await client.post(
                f"{RUNTIME_URL}{path}",
                json=body or {},
                headers={"Authorization": f"Bearer {SERVICE_TOKEN}"},
            )
            if resp.status_code == 200:
                return resp.json()
            try:
                return {"error": resp.json().get("detail", resp.text)}
            except Exception:
                return {"error": resp.text}
    except Exception as e:
        return {"error": f"Runtime unreachable: {e}"}


@mcp_server.list_tools()
async def list_tools():
    return [
        Tool(name="cog_send", description="Send a message to the cognitive agent and get a response.",
             inputSchema={"type": "object", "properties": {
                 "text": {"type": "string", "description": "Message text to send"},
                 "database": {"type": "string", "description": "Optional: database name for query_db context"},
             }, "required": ["text"]}),
        Tool(name="cog_trace", description="Get recent trace events from the pipeline (HUD events, tool calls, audit).",
             inputSchema={"type": "object", "properties": {
                 "last": {"type": "integer", "description": "Number of recent events (default 20)", "default": 20},
                 "filter": {"type": "string", "description": "Comma-separated event types to filter (e.g. 'tool_call,controls')"},
             }}),
        Tool(name="cog_history", description="Get recent chat messages from the active session.",
             inputSchema={"type": "object", "properties": {
                 "last": {"type": "integer", "description": "Number of recent messages (default 20)", "default": 20},
             }}),
        Tool(name="cog_state", description="Get the current memorizer state (mood, topic, language, facts).",
             inputSchema={"type": "object", "properties": {}}),
        Tool(name="cog_clear", description="Clear the active session (history, state, controls).",
             inputSchema={"type": "object", "properties": {}}),
        Tool(name="cog_graph", description="Get the active graph definition (nodes, edges, description).",
             inputSchema={"type": "object", "properties": {}}),
        Tool(name="cog_graph_list", description="List all available graph definitions.",
             inputSchema={"type": "object", "properties": {}}),
        Tool(name="cog_graph_switch", description="Switch the active graph for new sessions.",
             inputSchema={"type": "object", "properties": {
                 "name": {"type": "string", "description": "Graph name to switch to"},
             }, "required": ["name"]}),
    ]


@mcp_server.call_tool()
async def call_tool(name: str, arguments: dict):
    if name == "cog_send":
        text = arguments.get("text", "")
        if not text:
            return [TextContent(type="text", text="ERROR: Missing 'text' argument.")]

        # Step 1: check runtime is ready
        check = await _proxy_post("/api/send/check")
        if "error" in check:
            return [TextContent(type="text", text=f"ERROR: {check['error']}")]
        if not check.get("ready"):
            return [TextContent(type="text", text=f"ERROR: {check.get('reason', 'unknown')}: {check.get('detail', '')}")]

        # Step 2: queue message
        send = await _proxy_post("/api/send", {"text": text})
        if "error" in send:
            return [TextContent(type="text", text=f"ERROR: {send['error']}")]
        msg_id = send.get("id", "")

        # Step 3: poll for result (max 30s)
        import asyncio
        for _ in range(60):
            await asyncio.sleep(0.5)
            result = await _proxy_get("/api/result")
            if "error" in result:
                return [TextContent(type="text", text=f"ERROR: {result['error']}")]
            status = result.get("status", "")
            if status == "done":
                return [TextContent(type="text", text=result.get("response", "[no response]"))]
            if status == "error":
                return [TextContent(type="text", text=f"ERROR: {result.get('detail', 'pipeline failed')}")]
        return [TextContent(type="text", text="ERROR: Pipeline timeout (30s)")]

    elif name == "cog_trace":
        last = arguments.get("last", 20)
        event_filter = arguments.get("filter", "")
        params = {"last": last}
        if event_filter:
            params["filter"] = event_filter
        result = await _proxy_get("/api/trace", params)
        if "error" in result:
            return [TextContent(type="text", text=f"ERROR: {result['error']}")]
        # Format trace events compactly
        events = result.get("lines", [])
        lines = []
        for e in events:
            node = e.get("node", "?")
            event = e.get("event", "?")
            detail = e.get("detail", "")
            line = f"{node:12s} {event:20s} {detail}"
            lines.append(line.rstrip())
        return [TextContent(type="text", text="\n".join(lines) if lines else "(no events)")]

    elif name == "cog_history":
        last = arguments.get("last", 20)
        result = await _proxy_get("/api/history", {"last": last})
        if "error" in result:
            return [TextContent(type="text", text=f"ERROR: {result['error']}")]
        return [TextContent(type="text", text=json.dumps(result.get("messages", []), indent=2))]

    elif name == "cog_state":
        result = await _proxy_get("/api/state")
        if "error" in result:
            return [TextContent(type="text", text=f"ERROR: {result['error']}")]
        return [TextContent(type="text", text=json.dumps(result, indent=2))]

    elif name == "cog_clear":
        result = await _proxy_post("/api/clear")
        if "error" in result:
            return [TextContent(type="text", text=f"ERROR: {result['error']}")]
        return [TextContent(type="text", text="Session cleared.")]

    elif name == "cog_graph":
        result = await _proxy_get("/api/graph/active")
        if "error" in result:
            return [TextContent(type="text", text=f"ERROR: {result['error']}")]
        return [TextContent(type="text", text=json.dumps(result, indent=2))]

    elif name == "cog_graph_list":
        result = await _proxy_get("/api/graph/list")
        if "error" in result:
            return [TextContent(type="text", text=f"ERROR: {result['error']}")]
        return [TextContent(type="text", text=json.dumps(result.get("graphs", []), indent=2))]

    elif name == "cog_graph_switch":
        gname = arguments.get("name", "")
        if not gname:
            return [TextContent(type="text", text="ERROR: Missing 'name' argument.")]
        result = await _proxy_post("/api/graph/switch", {"name": gname})
        if "error" in result:
            return [TextContent(type="text", text=f"ERROR: {result['error']}")]
        return [TextContent(type="text", text=f"Switched to graph '{result.get('name', gname)}'. New sessions will use this graph.")]

    else:
        return [TextContent(type="text", text=f"Unknown tool: {name}")]


# Mount MCP SSE endpoints
@app.get("/mcp/sse")
async def mcp_sse(request: Request, user=Depends(require_auth)):
    async with _mcp_transport.connect_sse(request.scope, request.receive, request._send) as streams:
        await mcp_server.run(streams[0], streams[1], mcp_server.create_initialization_options())


@app.post("/mcp/messages/")
async def mcp_messages(request: Request, user=Depends(require_auth)):
    await _mcp_transport.handle_post_message(request.scope, request.receive, request._send)