This is an attempt to reproduce MCP's Framework does not handle refreshed tokens correctly issue.
uv run server.py
Connect a client, e.g. Claude Code.
claude mcp add dice --transport http http://127.0.0.1:6464/mcp
Type /mcp and authenticate with the dice server. After authentication, the log immediately shows numerous calls to exchange_refresh_token.
2025-10-06 09:28:22,210 - __main__ - INFO - Refreshed access token: fake_token_67352b806... (length: 43, expires in 30s)
2025-10-06 09:28:22,310 - __main__ - INFO - Refreshed access token: fake_token_513e5f8e1... (length: 43, expires in 30s)
2025-10-06 09:28:22,425 - __main__ - INFO - Refreshed access token: fake_token_0e0884fca... (length: 43, expires in 30s)
2025-10-06 09:28:22,561 - __main__ - INFO - Refreshed access token: fake_token_0d3d9f5dc... (length: 43, expires in 30s)
2025-10-06 09:28:22,630 - __main__ - INFO - Refreshed access token: fake_token_f1c257baf... (length: 43, expires in 30s)
2025-10-06 09:28:22,715 - __main__ - INFO - Refreshed access token: fake_token_66c6bacbb... (length: 43, expires in 30s)
2025-10-06 09:28:22,716 - __main__ - INFO - Refreshed access token: fake_token_67a7d8fe4... (length: 43, expires in 30s)
2025-10-06 09:28:22,918 - __main__ - INFO - Refreshed access token: fake_token_b894617ab... (length: 43, expires in 30s)
2025-10-06 09:28:30,191 - __main__ - INFO - Refreshed access token: fake_token_7a108f0ab... (length: 43, expires in 30s)
Ask Claude Code to "roll the dice". Despite ongoing calls to exchange_refresh_token, the tool receives an outdated access token from the context.
2025-10-06 09:28:30,265 - mcp.server.lowlevel.server - INFO - Processing request of type CallToolRequest
2025-10-06 09:28:30,265 - __main__ - INFO - Tool called with token: fake_token_513e5f8e1... (expires in 22s)
2025-10-06 09:28:30,265 - __main__ - INFO - Rolled 6-sided dice: 4
INFO: 127.0.0.1:62590 - "GET /.well-known/oauth-authorization-server/mcp HTTP/1.1" 404 Not Found
INFO: 127.0.0.1:62591 - "GET /.well-known/oauth-authorization-server HTTP/1.1" 200 OK
2025-10-06 09:29:32,945 - __main__ - INFO - Loading refresh token: refresh_63764ff2b0e4... (expires in 3530s)
2025-10-06 09:29:32,945 - __main__ - INFO - Refreshed access token: fake_token_5ce976e46... (length: 43, expires in 30s)
INFO: 127.0.0.1:62593 - "POST /token HTTP/1.1" 200 OK
INFO: 127.0.0.1:62590 - "POST /mcp HTTP/1.1" 200 OK
2025-10-06 09:29:33,018 - mcp.server.lowlevel.server - INFO - Processing request of type CallToolRequest
2025-10-06 09:29:33,018 - __main__ - INFO - Tool called with token: fake_token_513e5f8e1... (expires in -41s)
2025-10-06 09:29:33,018 - __main__ - INFO - Rolled 6-sided dice: 1