char-fork/llama.cpp

git clone https://git.t4t.associates/char-fork/llama.cpp

Xuan-Son Nguyenserver: support MCP stdio (#26062)20455a4ad

char/aliceai-t5-moe
brancheschar/aliceai-t5-moeall refs →
3.2 KiB114 linesraw
1#!/usr/bin/env python3
2"""
3MCP server that crashes after receiving a specific tool call.
4"""
5import json
6import sys
7import os
8
9def handle_initialize(params, req_id):
10    return {
11        "jsonrpc": "2.0",
12        "id": req_id,
13        "result": {
14            "protocolVersion": "2024-11-05",
15            "capabilities": {"tools": {}},
16            "serverInfo": {"name": "crash-test", "version": "1.0"}
17        }
18    }
19
20def handle_tools_list(params, req_id):
21    return {
22        "jsonrpc": "2.0",
23        "id": req_id,
24        "result": {
25            "tools": [
26                {
27                    "name": "echo",
28                    "description": "Echo back the input message",
29                    "inputSchema": {
30                        "type": "object",
31                        "properties": {
32                            "message": {"type": "string"}
33                        }
34                    }
35                },
36                {
37                    "name": "crash",
38                    "description": "Crash the server",
39                    "inputSchema": {
40                        "type": "object",
41                        "properties": {}
42                    }
43                }
44            ]
45        }
46    }
47
48def handle_tools_call(params, req_id):
49    tool_name = params.get("name")
50    arguments = params.get("arguments", {})
51
52    if tool_name == "echo":
53        message = arguments.get("message", "")
54        return {
55            "jsonrpc": "2.0",
56            "id": req_id,
57            "result": {
58                "content": [{"type": "text", "text": f"echo: {message}"}]
59            }
60        }
61    elif tool_name == "crash":
62        # Send a partial response then exit
63        sys.stdout.write(json.dumps({"jsonrpc": "2.0", "id": req_id, "result": {"content": [{"type": "text", "text": "crashing..."}]}}) + "\n")
64        sys.stdout.flush()
65        os._exit(1)
66    else:
67        return {
68            "jsonrpc": "2.0",
69            "id": req_id,
70            "error": {"code": -32602, "message": f"Unknown tool: {tool_name}"}
71        }
72
73HANDLERS = {
74    "initialize": handle_initialize,
75    "tools/list": handle_tools_list,
76    "tools/call": handle_tools_call,
77}
78
79def main():
80    sys.stdout = os.fdopen(sys.stdout.fileno(), "w", buffering=1)
81    sys.stderr = os.fdopen(sys.stderr.fileno(), "w", buffering=1)
82
83    for line in sys.stdin:
84        line = line.strip()
85        if not line:
86            continue
87        try:
88            request = json.loads(line)
89        except json.JSONDecodeError:
90            continue
91
92        method = request.get("method")
93        req_id = request.get("id")
94        params = request.get("params", {})
95
96        # JSON-RPC 2.0: a message without an id is a notification and must not receive a response
97        if req_id is None:
98            continue
99
100        handler = HANDLERS.get(method)
101        if handler:
102            response = handler(params, req_id)
103        else:
104            response = {
105                "jsonrpc": "2.0",
106                "id": req_id,
107                "error": {"code": -32601, "message": f"Method not found: {method}"}
108            }
109
110        sys.stdout.write(json.dumps(response) + "\n")
111        sys.stdout.flush()
112
113if __name__ == "__main__":
114    main()