claude-code - 💡(How to fix) Fix [BUG] URL-mode elicitation/create not supported — server-initiated OAuth flows fails with not supported error [2 comments, 2 participants]

json
{
  "jsonrpc": "2.0",
  "id": 100000,
  "method": "elicitation/create",
  "params": {
    "mode": "url",
    "elicitationId": "uuid",
    "url": <AUTH-URL>,
    "message": "Please authorize to continue."
  }
}

---

{"jsonrpc": "2.0", "id": 100000, "error": {"code": -32602, "message": "MCP error -32602: Client does not support URL-mode elicitation requests"}}

---

{"method": "initialize", "params": {"protocolVersion": "2025-11-25", "capabilities": {"roots": {}, "elicitation": {"form": {}, "url": {}}}, "clientInfo": {"name": "claude-code", "version": "2.1.87"}}, "jsonrpc": "2.0", "id": 0}

---

MCP server "server name": Elicitation request received during initialization: {"method":"elicitation/create","params":{"mode":"url","message":"Please authorize to continue.","elicitationId":"0f5e7464-72eb-40ce-aa06-511c258b7c9a","url":"<auth_url>"}}

---

elicitation response (id=100000): {"result": {"action": "cancel"}, "jsonrpc": "2.0", "id": 100000}

---

Version 108




{"jsonrpc": "2.0", "id": 100000, "error": {"code": -32602, "message": "MCP error -32602: Client does not support URL-mode elicitation requests"}}


Version 87 which declares the URL mode drops silently.



 MCP server "server name": Elicitation request received during initialization: {"method":"elicitation/create","params":{"mode":"url","message":"Please authorize to continue.","elicitationId":"0f5e7464-72eb-40ce-aa06-511c258b7c9a","url":"<auth_url>"}}


No url shown to user and server received response:


 elicitation response (id=100000): {"result": {"action": "cancel"}, "jsonrpc": "2.0", "id": 100000}

---

python
#!/usr/bin/env python3
"""Minimal MCP server that sends URL-mode elicitation after initialize."""
import json, sys

def write(msg):
    sys.stdout.write(json.dumps(msg) + "\n")
    sys.stdout.flush()

for line in sys.stdin:
    msg = json.loads(line.strip())
    method = msg.get("method", "")
    msg_id = msg.get("id")

    if method == "initialize":
        write({
            "jsonrpc": "2.0", "id": msg_id,
            "result": {
                "protocolVersion": "2025-11-25",
                "capabilities": {"tools": {}, "elicitation": {"url": {}}},
                "serverInfo": {"name": "elicitation-test", "version": "1.0.0"},
            }
        })

    elif method == "notifications/initialized":
        # Send URL-mode elicitation to client
        write({
            "jsonrpc": "2.0", "id": 1,
            "method": "elicitation/create",
            "params": {
                "mode": "url",
                "elicitationId": "550e8400-e29b-41d4-a716-446655440000",
                "url": "https://example.com/authorize",
                "message": "Please authorize to continue.",
            }
        })

    elif method == "tools/list":
        write({"jsonrpc": "2.0", "id": msg_id, "result": {"tools": []}})

    elif "result" in msg or "error" in msg:
        # Log client's response to elicitation/create
        print(json.dumps(msg), file=sys.stderr)

---

{
  "mcpServers": {
    "elicitation-test": {
      "type": "stdio",
      "command": "python3",
      "args": ["elicitation_test_server.py"]
    }
  }
}