Copilot repeats 5x "Request failed due to a transient API error. Retrying" and "CAPIError: 503" #2166
Description
Describe the bug
When I use Claude Opus 4.6 / Sonnet 4.6 and interact with it for several rounds, Copilot CLI often gets stuck and reports:
Request failed due to a transient API error. Retrying...
for 5 times. And finally reports:
Execution failed: Error: Failed to get response from the AI model; retried 5 times (total retry wait time: ~90 seconds) Last error: CAPIError: 503 {"error":{"message":"HTTP/2 GOAWAY connection terminated","type":"connection_error"}}
- It does not report
you've hit a rate limit, so this issue seems to be different from Request failed due to a transient API error. Retrying... #2101, Request failed #2073, etc. - It does not report
AssertionError, so this issue seems to be different from *Claude Sonnet 4.6 - Execution failed: Error: Failed to get response from the AI model; retried 5 times (total retry wait time: 84.70107509705375 seconds) Last error: CAPIError: 503 {"error":{"message":"HTTP/2 GOAWAY connection terminated","type":"connection_error"}} #2050, etc.
These days, I have met this issue many times. And when I met it, I switched the model to GPT-5.4, chat with GPT-5.4 for one round, switched back to Claude Opus 4.6, and finally Copilot CLI worked normally again.
I am a Copilot Pro+ user, and this issue is quite annoying for me! Hope it gets fixed as soon as possible.
Affected version
GitHub Copilot CLI 1.0.9
Steps to reproduce the behavior
/modeland chooseClaude Opus 4.6/Claude Sonnet 4.6- prompt it, and when the session gets long, the issue could be reproduced
Expected behavior
No Execution failed: Error: Failed to get response from the AI model; retried 5 times (total retry wait time: ~90 seconds) Last error: CAPIError: 503 {"error":{"message":"HTTP/2 GOAWAY connection terminated","type":"connection_error"}} again!
Additional context
- I am on x86_64 Linux and ssh + tmux + bash
- The log:
2026-03-19T12:45:30.030Z [INFO] --- Start of group: Sending request to the AI model ---
2026-03-19T12:45:30.064Z [DEBUG] [telemetry-queue] Flushing 1 events (2570 B → 1246 B gzipped)
2026-03-19T12:45:34.940Z [WARNING] [StreamingChunkDisplay] Received a chunk with a different streaming ID: f711aee1-83be-4b01-b56f-5e3069d245b3
2026-03-19T12:46:36.202Z [INFO] Proxy configuration: HTTP_PROXY=http://192.168.5.58:1080, HTTPS_PROXY=http://192.168.5.58:1080, NO_PROXY=(not set)
2026-03-19T12:46:36.203Z [WARNING] Detected HTTP/2 GOAWAY error, resetting global dispatcher and retrying the request.
2026-03-19T12:46:36.205Z [ERROR] error (Request-ID null)
2026-03-19T12:46:36.206Z [ERROR] {
"status": 503,
"headers": {},
"requestID": null,
"error": {
"error": {
"message": "HTTP/2 GOAWAY connection terminated",
"type": "connection_error"
}
},
"request_id": null,
"ghRequestId": null,
"name": "CAPIError",
"cause": {
"cause": {
"name": "TypeError",
"message": "terminated",
"stack": "TypeError: terminated\n at D3e.m (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:164:43943)\n at D3e.emit (node:events:508:28)\n at D3e.terminate (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:164:30659)\n at Object.onError (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:164:46240)\n at sft.onError (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:37:33212)\n at Object.Qgo [as errorRequest] (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:37:23127)\n at TLSSocket.$0o (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:49:12551)\n at TLSSocket.emit (node:events:520:35)\n at node:net:346:12\n at Socket.done (node:_tls_wrap:649:7)",
"cause": {
"name": "SocketError",
"code": "UND_ERR_SOCKET",
"socket": {
"localAddress": "10.244.38.65",
"localPort": 44102,
"remoteAddress": "192.168.5.58",
"remotePort": 1080,
"remoteFamily": "IPv4",
"bytesWritten": 327270,
"bytesRead": 4946
},
"message": "other side closed",
"stack": "SocketError: other side closed\n at TLSSocket.q0o (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:49:12066)\n at TLSSocket.emit (node:events:520:35)\n at endReadableNT (node:internal/streams/readable:1701:12)\n at process.processTicksAndRejections (node:internal/process/task_queues:89:21)"
}
},
"name": "Error",
"message": "terminated",
"stack": "Error: terminated\n at t.Dyr (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:1990:4649)\n at process.processTicksAndRejections (node:internal/process/task_queues:103:5)"
},
"message": "503 {\"error\":{\"message\":\"HTTP/2 GOAWAY connection terminated\",\"type\":\"connection_error\"}}",
"stack": "CAPIError: 503 {\"error\":{\"message\":\"HTTP/2 GOAWAY connection terminated\",\"type\":\"connection_error\"}}\n at t.fromAPIError (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:2007:949)\n at wst.getCompletionWithTools (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:2007:10970)\n at process.processTicksAndRejections (node:internal/process/task_queues:103:5)\n at async mxe.getCompletionWithTools (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:2019:2292)\n at async t.runAgenticLoop (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:2473:36636)\n at async t.processQueuedItems (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:2473:5634)\n at async t.processQueue (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:2473:896)\n at async t.send (file:///home/user/.copilot/pkg/universal/1.0.9/app.js:2471:3497)\n at async file:///home/user/.copilot/pkg/universal/1.0.9/app.js:4968:1634"
}
2026-03-19T12:46:36.206Z [DEBUG] Failed to get response from the AI model: CAPIError: 503 {"error":{"message":"HTTP/2 GOAWAY connection terminated","type":"connection_error"}}
2026-03-19T12:46:36.206Z [DEBUG] Inner error: {
"error": {
"message": "HTTP/2 GOAWAY connection terminated",
"type": "connection_error"
}
}
2026-03-19T12:46:36.206Z [DEBUG] Retrying after 7.454450470719868 seconds (API error)...
2026-03-19T12:46:43.677Z [DEBUG] Retrying after 9 seconds... Will try again now!