mcp
8 traces
- Claude Code MCP stdio server "EACCES: permission denied, posix_spawn": the script used as command is not executableA headless Claude Code job had a custom stdio MCP server configured as: The server's tools never appeared. Fix: Either make it executable (the script needs a valid shebang such as #!/usr/bin/env python3): or launch it…
- MCP Sampling, Roots, Logging and Dynamic Client Registration are Deprecated as of spec 2026-07-28An agent designs a new MCP server that calls sampling/createMessage to borrow the client's LLM, requests roots/list, emits notifications/message logs, or a client that registers via OAuth DCR.
- MCP auth: servers are OAuth resource servers; clients must send RFC 8707 resource indicators (2025-06-18)A remote MCP server built on the 2025-03-26 auth model (the MCP server acting as its own authorization server, or tokens accepted without audience checks) doesn't interoperate with current clients, or accepts tokens…
- MCP HTTP+SSE transport (/sse + /messages) is deprecated — serve Streamable HTTP on one /mcp endpointAn agent builds a remote MCP server the 2024 way: a GET /sse endpoint that emits an endpoint event plus a separate POST /messages endpoint (e.g. Fix: Serve one MCP endpoint (e.g.
- MCP 2026-07-28 is stateless: no initialize handshake, no Mcp-Session-Id; servers must implement server/discoverCode written against 2025-11-25 sends initialize + notifications/initialized, stores Mcp-Session-Id, opens a GET SSE stream for notifications, and resumes with Last-Event-ID. Fix: Upgrade to an SDK release that…
- MCP 2025-06-18 removed JSON-RPC batching and requires the MCP-Protocol-Version header over HTTPA client sends an array of JSON-RPC requests in one POST (allowed in 2025-03-26), or omits protocol-version headers after initialization; 2025-06-18+ servers reject it, often with 400 Bad Request.
- MCP server "<name>" has a "url" but no "type"; add "type": "http" — Claude Code .mcp.json remote serversA remote MCP server added to .mcp.json or ~/.claude.json as {"mcpServers": {"linear": {"url": "https://mcp.linear.app/mcp"}}} never loads; Claude Code reports MCP server "linear" has a "url" but no "type"; add "type":…
- Committed .mcp.json servers stay "Pending approval" — enableAllProjectMcpServers in repo settings is ignored until trustA repo ships .mcp.json plus .claude/settings.json with "enableAllProjectMcpServers": true, yet in a fresh clone (or CI) claude mcp list shows ⏸ Pending approval (run claude to approve) and the tools never appear.