Files
openswarm/backend/apps/agents/mcp_meta_server.py
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238 lines
9.0 KiB
Python

#!/usr/bin/env python3
"""Stdio MCP server exposing the MCP activation gate (MCPList/MCPSearch/MCPActivate)."""
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/mcp-meta"
PARENT_SESSION_ID = os.environ.get("OPENSWARM_PARENT_SESSION_ID", "")
TOOLS = [
{
"name": "MCPList",
"description": (
"List installed MCP servers (name, one-sentence purpose, "
"active/available status). Cheap. Use for a broad survey before "
"picking a server."
),
"inputSchema": {
"type": "object",
"properties": {},
"additionalProperties": False,
},
},
{
"name": "MCPSearch",
"description": (
"Rank MCP servers by relevance to a query. Use before MCPActivate "
"when unsure which server fits. Tools are NOT callable until you "
"also MCPActivate."
),
"inputSchema": {
"type": "object",
"properties": {
"query": {
"type": "string",
"description": "What you need (e.g. 'send email', 'post to slack').",
},
},
"required": ["query"],
"additionalProperties": False,
},
},
{
"name": "MCPActivate",
"description": (
"Request activation of an MCP server for this session. Triggers a "
"user approval prompt; on approve the server's tools become callable "
"next turn. Always confirm the server name via MCPList/MCPSearch first; "
"invalid names return alternatives instead of activating."
),
"inputSchema": {
"type": "object",
"properties": {
"server_name": {
"type": "string",
"description": "Sanitized name from MCPList/MCPSearch (e.g. 'gmail', 'slack').",
},
"reason": {
"type": "string",
"description": "Why you need it; shown to the user in the approval prompt.",
},
},
"required": ["server_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:
with urllib.request.urlopen(req, timeout=60) as resp:
return json.loads(resp.read().decode())
except urllib.error.HTTPError as e:
body = e.read().decode() if e.fp else str(e)
return {"error": f"HTTP {e.code}: {body}"}
except Exception as e:
return {"error": str(e)}
def format_servers(servers: list[dict], heading: str = "") -> str:
if not servers:
return ""
lines = []
if heading:
lines.append(heading)
for s in servers:
name = s.get("name", "")
desc = s.get("description") or f"{name} integration"
status = s.get("status", "available")
lines.append(f"- `{name}` [{status}]; {desc}")
return "\n".join(lines)
def handle_tool_call(tool_name: str, arguments: dict) -> dict:
if tool_name == "MCPList":
result = call_backend("list", {})
if "error" in result:
return {"content": [{"type": "text", "text": f"Error: {result['error']}"}], "isError": True}
active = result.get("active", [])
available = result.get("available", [])
if not active and not available:
return {"content": [{"type": "text", "text": "No MCP servers are installed. The user can install one from the Tools page."}]}
parts = []
if active:
parts.append(format_servers(active, "Active (callable now):"))
if available:
parts.append(format_servers(available, "Available (call MCPActivate to enable):"))
return {"content": [{"type": "text", "text": "\n\n".join(parts)}]}
if tool_name == "MCPSearch":
query = arguments.get("query", "")
if not query:
return {"content": [{"type": "text", "text": "Error: query is required"}], "isError": True}
result = call_backend("search", {"query": query})
if "error" in result:
return {"content": [{"type": "text", "text": f"Error: {result['error']}"}], "isError": True}
matches = result.get("matches", [])
if not matches:
return {"content": [{"type": "text", "text": f"No MCP servers matched '{query}'. Try MCPList to see everything installed, or tell the user no suitable server is connected."}]}
body = format_servers(matches, f"Top matches for '{query}':")
body += "\n\nNext step: pick one and call MCPActivate(server_name) to request activation."
return {"content": [{"type": "text", "text": body}]}
if tool_name == "MCPActivate":
server_name = arguments.get("server_name", "")
reason = arguments.get("reason", "")
if not server_name:
return {"content": [{"type": "text", "text": "Error: server_name is required"}], "isError": True}
result = call_backend("activate", {"server_name": server_name, "reason": reason})
if "error" in result:
return {"content": [{"type": "text", "text": f"Error: {result['error']}"}], "isError": True}
if result.get("status") == "unknown_server":
available = result.get("available", [])
return {
"content": [{
"type": "text",
"text": (
f"Unknown MCP server '{server_name}'. Valid options: "
+ ", ".join(f"`{s}`" for s in available)
+ ". Call MCPList for full descriptions."
),
}],
"isError": True,
}
if result.get("status") == "already_active":
return {"content": [{"type": "text", "text": f"`{server_name}` is already active for this session; its tools should be callable now."}]}
if result.get("status") == "activated":
return {
"content": [{
"type": "text",
"text": (
f"Activated `{server_name}`. Its tools (`mcp__{server_name}__*`) "
f"are NOT callable in this turn; the transport snapshot is "
f"already locked. This turn will end automatically and a "
f"hidden continuation turn will fire with the new tools "
f"loaded. Do not attempt any other tool call now."
),
}],
}
return {"content": [{"type": "text", "text": f"Unexpected response: {json.dumps(result)}"}], "isError": True}
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-mcp-meta",
"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:
result = handle_tool_call(tool_name, arguments)
send_response(id_, result)
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()