#!/usr/bin/env python3 """Stdio MCP server letting ANY agent create an OpenSwarm App on the canvas. One tool, CreateApp, backed by /api/outputs/agent-create. Always on, no activation gate: app-building is a core capability, not a third-party MCP. The backend seeds a React/Vite workspace, registers the App, links it to the calling session, and drops a live preview card next to the agent on the dashboard. The tool result hands back the workspace path + the full App Builder reference so the agent can start writing code immediately.""" import json import os import sys import urllib.error import urllib.request BACKEND_PORT = os.environ.get("OPENSWARM_PORT", "8324") BACKEND_AUTH = os.environ.get("OPENSWARM_AUTH_TOKEN", "") BACKEND_URL = f"http://127.0.0.1:{BACKEND_PORT}/api/outputs" PARENT_SESSION_ID = os.environ.get("OPENSWARM_PARENT_SESSION_ID", "") TOOLS = [ { "name": "CreateApp", "description": ( "Create a new OpenSwarm App: a real React 18 + TypeScript + Vite web app " "(optional FastAPI backend) that appears as a live preview card on the " "user's dashboard, next to you. HARD RULE: call this only when the user's " "message explicitly says to build/make/create an app, tool, game, or " "dashboard. A question, plan, list, comparison, or a wish to track or " "organize something is NOT an app request: answer it in chat (rich " "components beat prose), then offer to build an app and wait for a yes. " "Returns the workspace path to write code in plus " "the App Builder reference (stack, layout, rules) — follow it. To EDIT an " "app that already exists, don't call this; edit its workspace files " "directly (the path is in your context when the user selects the app, " "and the preview hot-reloads on save)." ), "inputSchema": { "type": "object", "properties": { "name": { "type": "string", "description": "Short human title for the app, e.g. 'Pomodoro Timer'.", }, "description": { "type": "string", "description": "One sentence on what the app does.", }, }, "required": ["name"], "additionalProperties": False, }, }, ] def send_response(id_, result=None, error=None): msg = {"jsonrpc": "2.0", "id": id_} if error is not None: msg["error"] = error else: msg["result"] = result sys.stdout.write(json.dumps(msg) + "\n") sys.stdout.flush() def call_backend(action: str, payload: dict) -> dict: full = {**payload, "parent_session_id": PARENT_SESSION_ID} body = json.dumps(full).encode() headers = {"Content-Type": "application/json"} if BACKEND_AUTH: headers["Authorization"] = f"Bearer {BACKEND_AUTH}" req = urllib.request.Request( f"{BACKEND_URL}/{action}", data=body, headers=headers, method="POST" ) try: # Seeding copies the template + links the warm node_modules cache; give it room. with urllib.request.urlopen(req, timeout=120) as resp: return json.loads(resp.read().decode()) except urllib.error.HTTPError as e: detail = e.read().decode() if e.fp else str(e) return {"error": f"HTTP {e.code}: {detail}"} except Exception as e: return {"error": str(e)} def handle_tool_call(tool_name: str, arguments: dict) -> dict: if tool_name == "CreateApp": name = str(arguments.get("name") or "").strip() if not name: return {"content": [{"type": "text", "text": "Error: `name` is required."}], "isError": True} result = call_backend("agent-create", { "name": name, "description": str(arguments.get("description") or "").strip(), }) if "error" in result: return {"content": [{"type": "text", "text": f"Error: {result['error']}"}], "isError": True} path = result.get("path") # Point at SKILL.md instead of inlining the ~6.5k-token reference: it's written to the workspace at seed time, so a one-time Read keeps it out of the transcript (where an inline copy would rot for the rest of the session). Read it BEFORE building. lines = [ f"App '{name}' created and its live preview card is now on the user's dashboard.", f"- workspace: {path}", f"- output_id: {result.get('output_id')}", "", f"NEXT: read {path}/SKILL.md now — it's the full App Builder reference (stack, layout, rules); follow it.", "Then build by writing files under the workspace path; the preview hot-reloads on save.", "Housekeeping: write meta.json (name/description) first; `bash restart.sh` restarts the runtime; `.openswarm/terminal.log` is the live terminal (check it before declaring done).", ] return {"content": [{"type": "text", "text": "\n".join(lines)}]} return {"content": [{"type": "text", "text": f"Unknown tool: {tool_name}"}], "isError": True} def main(): for line in sys.stdin: line = line.strip() if not line: continue try: msg = json.loads(line) except json.JSONDecodeError: continue method = msg.get("method") id_ = msg.get("id") params = msg.get("params", {}) if method == "initialize": send_response(id_, { "protocolVersion": "2024-11-05", "capabilities": {"tools": {}}, "serverInfo": {"name": "openswarm-apps", "version": "1.0.0"}, }) elif method == "notifications/initialized": pass elif method == "tools/list": send_response(id_, {"tools": TOOLS}) elif method == "tools/call": tool_name = params.get("name", "") arguments = params.get("arguments", {}) try: send_response(id_, handle_tool_call(tool_name, arguments)) except Exception as e: send_response(id_, error={"code": -32000, "message": str(e)}) elif method == "resources/list": send_response(id_, {"resources": []}) elif method == "prompts/list": send_response(id_, {"prompts": []}) elif id_ is not None: send_response(id_, error={"code": -32601, "message": f"Method not found: {method}"}) if __name__ == "__main__": main()