Error: MCP error 0: lockdown cache is not configured

[cg505]

Describe the bug

Using the remote MCP server with this configuration in claude code:

    "github": {
      "type": "http",
      "url": "https://api.githubcopilot.com/mcp",
      "headers": {
        "X-MCP-Toolsets": "pull_requests,issues",
        "X-MCP-Readonly": "true",
        "X-MCP-Lockdown": "true",
        "Authorization": "Bearer xxxxx"
      }
    }

A new session that runs github - Get details for a single pull request fails with  Error: MCP error 0: lockdown cache is not configured

Affected version

Whatever is running on api.githubcopilot.com

Steps to reproduce the behavior

1. Add above config to claude code
2. Start a session, ask it to address comments on a specific PR
3. It tries to use MCP and fails with the above error

Expected vs actual behavior

Expected: It provides PR comments or fails with a permission error
Actual: It throws the above error

Logs

claude code jsonl from a session where this happened:

{"parentUuid":"9d31c9ec-aabd-4846-9e3a-4612a6b1b983","isSidechain":false,"userType":"external","cwd":"/home/cooperc/a/skypilot5","sessionId":"9d7bac0e-6183-4241-bcb1-e7fe050db023","version":"2.1.15","gitBranch":"format-length","message":{"model":"claude-opus-4-5-20251101","id":"msg_01GXCy1RF8BxBa8DUDF8c3Pz","type":"message","role":"assistant","content":[{"type":"tool_use","id":"toolu_017kwwZiBDFaPovf94ZnCfgH","name":"mcp__github__pull_request_read","input":{"method":"get","owner":"skypilot-org","repo":"skypilot","pullNumber":8652}}],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":10,"cache_creation_input_tokens":16712,"cache_read_input_tokens":13732,"cache_creation":{"ephemeral_5m_input_tokens":16712,"ephemeral_1h_input_tokens":0},"output_tokens":1,"service_tier":"standard"}},"requestId":"req_011CXNvrREFLPb9GpBPZBekK","type":"assistant","uuid":"9e8274e8-083b-4815-85fd-4c69a4c82b94","timestamp":"2026-01-22T18:58:29.604Z"}
{"parentUuid":"9e8274e8-083b-4815-85fd-4c69a4c82b94","isSidechain":false,"userType":"external","cwd":"/home/cooperc/a/skypilot5","sessionId":"9d7bac0e-6183-4241-bcb1-e7fe050db023","version":"2.1.15","gitBranch":"format-length","message":{"model":"claude-opus-4-5-20251101","id":"msg_01GXCy1RF8BxBa8DUDF8c3Pz","type":"message","role":"assistant","content":[{"type":"tool_use","id":"toolu_01FhqMxoH5VcrabvuHNTPwa1","name":"mcp__github__pull_request_read","input":{"method":"get_review_comments","owner":"skypilot-org","repo":"skypilot","pullNumber":8652}}],"stop_reason":null,"stop_sequence":null,"usage":{"input_tokens":10,"cache_creation_input_tokens":16712,"cache_read_input_tokens":13732,"cache_creation":{"ephemeral_5m_input_tokens":16712,"ephemeral_1h_input_tokens":0},"output_tokens":1,"service_tier":"standard"}},"requestId":"req_011CXNvrREFLPb9GpBPZBekK","type":"assistant","uuid":"93799265-f381-460c-93b6-ac6a6abc4752","timestamp":"2026-01-22T18:58:30.287Z"}
{"parentUuid":"93799265-f381-460c-93b6-ac6a6abc4752","isSidechain":false,"userType":"external","cwd":"/home/cooperc/a/skypilot5","sessionId":"9d7bac0e-6183-4241-bcb1-e7fe050db023","version":"2.1.15","gitBranch":"format-length","type":"progress","data":{"type":"mcp_progress","status":"started","serverName":"github","toolName":"pull_request_read"},"toolUseID":"toolu_017kwwZiBDFaPovf94ZnCfgH","parentToolUseID":"toolu_017kwwZiBDFaPovf94ZnCfgH","uuid":"788dde78-22b8-47ed-a523-022f4112836d","timestamp":"2026-01-22T18:58:35.965Z"}
{"parentUuid":"788dde78-22b8-47ed-a523-022f4112836d","isSidechain":false,"userType":"external","cwd":"/home/cooperc/a/skypilot5","sessionId":"9d7bac0e-6183-4241-bcb1-e7fe050db023","version":"2.1.15","gitBranch":"format-length","type":"progress","data":{"type":"mcp_progress","status":"failed","serverName":"github","toolName":"pull_request_read","elapsedTimeMs":901},"toolUseID":"toolu_017kwwZiBDFaPovf94ZnCfgH","parentToolUseID":"toolu_017kwwZiBDFaPovf94ZnCfgH","uuid":"387bd79b-4aff-4e88-b435-8d3d62bc5a0f","timestamp":"2026-01-22T18:58:36.866Z"}
{"parentUuid":"9e8274e8-083b-4815-85fd-4c69a4c82b94","isSidechain":false,"userType":"external","cwd":"/home/cooperc/a/skypilot5","sessionId":"9d7bac0e-6183-4241-bcb1-e7fe050db023","version":"2.1.15","gitBranch":"format-length","type":"user","message":{"role":"user","content":[{"type":"tool_result","content":"MCP error 0: lockdown cache is not configured","is_error":true,"tool_use_id":"toolu_017kwwZiBDFaPovf94ZnCfgH"}]},"uuid":"85a166ef-8e80-4cf4-940e-781a14ea28c0","timestamp":"2026-01-22T18:58:36.885Z","toolUseResult":"Error: MCP error 0: lockdown cache is not configured","sourceToolAssistantUUID":"9e8274e8-083b-4815-85fd-4c69a4c82b94"}
{"parentUuid":"85a166ef-8e80-4cf4-940e-781a14ea28c0","isSidechain":false,"userType":"external","cwd":"/home/cooperc/a/skypilot5","sessionId":"9d7bac0e-6183-4241-bcb1-e7fe050db023","version":"2.1.15","gitBranch":"format-length","type":"progress","data":{"type":"mcp_progress","status":"started","serverName":"github","toolName":"pull_request_read"},"toolUseID":"toolu_01FhqMxoH5VcrabvuHNTPwa1","parentToolUseID":"toolu_01FhqMxoH5VcrabvuHNTPwa1","uuid":"ea95760b-9fe1-403c-9fe8-f649d6f1ab29","timestamp":"2026-01-22T18:58:37.016Z"}
{"parentUuid":"ea95760b-9fe1-403c-9fe8-f649d6f1ab29","isSidechain":false,"userType":"external","cwd":"/home/cooperc/a/skypilot5","sessionId":"9d7bac0e-6183-4241-bcb1-e7fe050db023","version":"2.1.15","gitBranch":"format-length","type":"progress","data":{"type":"mcp_progress","status":"failed","serverName":"github","toolName":"pull_request_read","elapsedTimeMs":769},"toolUseID":"toolu_01FhqMxoH5VcrabvuHNTPwa1","parentToolUseID":"toolu_01FhqMxoH5VcrabvuHNTPwa1","uuid":"aa2b7f91-9bf0-4bc6-beec-671e14ac941c","timestamp":"2026-01-22T18:58:37.785Z"}
{"parentUuid":"93799265-f381-460c-93b6-ac6a6abc4752","isSidechain":false,"userType":"external","cwd":"/home/cooperc/a/skypilot5","sessionId":"9d7bac0e-6183-4241-bcb1-e7fe050db023","version":"2.1.15","gitBranch":"format-length","type":"user","message":{"role":"user","content":[{"type":"tool_result","content":"MCP error 0: lockdown cache is not configured","is_error":true,"tool_use_id":"toolu_01FhqMxoH5VcrabvuHNTPwa1"}]},"uuid":"8ff31166-d1d8-4b8c-ab0a-c28a17e82b7a","timestamp":"2026-01-22T18:58:37.794Z","toolUseResult":"Error: MCP error 0: lockdown cache is not configured","sourceToolAssistantUUID":"93799265-f381-460c-93b6-ac6a6abc4752"}