Getting chat ompletions error

[LeonarddeR]

I'm pretty often getting the following error in the command line when using this tool with Claude Code:

 ERROR  Failed to create chat completions Response { status: 400,                                           4:17:56 PM
  statusText: 'Bad Request',
  headers:
   Headers { 'content-security-policy': "default-src 'none'; sandbox",
     'content-type': 'text/plain; charset=utf-8',
     'strict-transport-security': 'max-age=31536000',
     'x-content-type-options': 'nosniff',
     'x-copilot-api-exp-assignment-context': 'xxx',
     'x-request-id': 'xxx',
     date: 'Mon, 27 Apr 2026 16:17:55 GMT',
     'content-length': '161',
     'x-github-backend': 'Kubernetes',
     'x-github-request-id': 'xx' },
  body: ReadableStream { locked: false, state: 'readable', supportsBYOB: true },
  bodyUsed: false,
  ok: false,
  redirected: false,
  type: 'basic',
  url: 'https://api.githubcopilot.com/chat/completions' }

As for the Claude models, I only seem to be able to use opus-4.7 for now. Both opus 4.6 and sonnet give these errors.

[betaHi]

Thanks for reporting this. I’ve made a few fixes.

Could you try the latest version?

npx betahi-copilot-bridge@latest start

If it still fails, could you share the exact command/workflow you used to reproduce it and the new bridge error log?

[LeonarddeR]

Thanks for looking into this.

I started the new version and in Claude, after pressing alt+p, selected the default model claude-sonnet-4.6.

Here is waht the bridge now outputs:

 ERROR  Failed to create chat completions { route: '/chat/completions',                                       09:21:36  
  model: 'claude-sonnet-4.6',                                                                                           
  status: 400,                                                                                                          
  statusText: 'Bad Request',                                                                                            
  body: 'Bad Request\n' }                                                                                               
 

It happens just after every random question.
The claude-sonnet-4.6 model is reported as bridge supported.

[betaHi]

Sorry this was still happening, and thanks for the report.

I tracked this down and published betahi-copilot-bridge@0.1.5 with a more conservative Claude reasoning fix.

I also validated the published package through npx betahi-copilot-bridge@latest start with both Claude Code and Codex CLI, plus live upstream request checks for the Claude/GPT/Gemini model families.

Please try:

npx betahi-copilot-bridge@latest start

If you still see the claude-sonnet-4.6 400 after updating to 0.1.5, please share the exact command, selected model, and the full error body from the bridge log so I can dig further.

[LeonarddeR]

I'm very grateful for your help, but unfortunately not much luck here.

Here is the full copilot-api output:

√ Loaded 40 Copilot models                                                                                    18:52:04
√ copilot-bridge listening on http://127.0.0.1:4142                                                           18:52:04
i copilot base url: https://api.githubcopilot.com                                                             18:52:04
i claude settings already up to date: C:\Users\leonard\.claude\settings.json                                  18:52:05
i codex model_reasoning_effort not set; using claude-opus-4.5's default reasoning effort                      18:52:05
i codex config already up to date: C:\Users\leonard\.codex\config.toml                                        18:52:05
i Available models:                                                                                           18:52:05
- claude-opus-4.6 (bridge-supported)
- claude-opus-4.7 (bridge-supported)
- claude-sonnet-4.6 (bridge-supported)
- gemini-3.1-pro-preview (bridge-supported)
- gpt-5.2-codex (bridge-supported)
- gpt-5.3-codex (bridge-supported)
- gpt-5.4-mini (bridge-supported)
- gpt-5.4 (bridge-supported)
- accounts/msft/routers/f185i3v4
- accounts/msft/routers/fmfeto88
- accounts/msft/routers/gdjv4v2v
- gpt-5-mini (bridge-supported)
- gpt-4o-mini-2024-07-18
- gpt-4o-2024-11-20
- gpt-4o-2024-08-06
- grok-code-fast-1
- text-embedding-3-small
- text-embedding-3-small-inference
- claude-sonnet-4 (bridge-supported)
- claude-sonnet-4.5 (bridge-supported)
- claude-opus-4.5 (bridge-supported)
- claude-haiku-4.5 (bridge-supported)
- gemini-3-flash-preview (bridge-supported)
- gemini-2.5-pro (bridge-supported)
- gpt-4.1-2025-04-14
- gpt-5.2 (bridge-supported)
- gpt-41-copilot
- gpt-3.5-turbo-0613
- gpt-4
- gpt-4-0613
- gpt-4-0125-preview
- gpt-4o-2024-05-13
- gpt-4-o-preview
- gpt-4.1 (bridge-supported)
- gpt-3.5-turbo
- gpt-4o-mini
- gpt-4
- gpt-4o (bridge-supported)
- gpt-4-o-preview
- text-embedding-ada-002

 ╭──────────────────────────────────────────────────────────────────────────────────╮
 │                                                                                  │
 │  🌐 Usage viewer                                                                 │
 │                                                                                  │
 │    https://betahi.github.io/copilot-bridge?endpoint=http://127.0.0.1:4142/usage  │
 │                                                                                  │
 ╰──────────────────────────────────────────────────────────────────────────────────╯

<-- POST /v1/messages?beta=true
--> POST /v1/messages?beta=true 200 3s
<-- POST /v1/messages?beta=true

 ERROR  Failed to create chat completions { route: '/chat/completions',                                       18:52:24
  model: 'claude-sonnet-4.6',
  status: 400,
  statusText: 'Bad Request',
  body: 'Bad Request\n' }

--> POST /v1/messages?beta=true 400 1s

In claude, I ran /model claude-sonnet-4.6, then just a random prompt: hello

[betaHi]

Thanks for the report. This may be caused by an upstream request shape issue, such as an invalid tool name or a tool schema field rejected by GitHub Copilot.

Could you run

npx betahi-copilot-bridge@latest start --debug

then reproduce the issue and share the relevant console logs that you feel are safe to share?

Please review/redact anything sensitive before posting.

[LeonarddeR]

Thanks for this, I'm pretty sure this will give more insight:

<-- POST /v1/messages?beta=true                                                                                         
                                                                                                                        
 ERROR  Failed to create chat completions { route: '/chat/completions',                                       13:33:40  
  model: 'claude-haiku-4.5',                                                                                            
  status: 400,                                                                                                          
  statusText: 'Bad Request',                                                                                            
  body: 'Bad Request\n',                                                                                                
  request:                                                                                                              
   '{"max_tokens":32000,"message_count":2,"stream":true,"tools":{"count":47,"invalidNames":["mcp__plugin_microsoft-docs_microsoft-learn__microsoft_code_sample_search","mcp__plugin_microsoft-docs_microsoft-learn__microsoft_docs_search"]}}' }
                                                                                                                        
--> POST /v1/messages?beta=true 400 1s                                                                                  
 

I have the microsoft Docs claude plugin installed which bundles the microsoft learn MCP server. When I disable the MCP server, the problem is gone.
Interestingly though, the problem doesn't occur on opus-4.7 and I even have used this plugin just fine with it.

[betaHi]

Thanks, the log is very helpful.

Because upstream models have different tool name length limits: claude-haiku-4.5 is limited to 64 characters, so the long Microsoft Learn MCP tool name caused a 400, while claude-opus-4.7 allows 128 characters, so the same tool name does not fail there.

Please try:

npx betahi-copilot-bridge@latest start

[LeonarddeR]

Thanks for the update. For haiku and sonnet it no works, but for claude-opus-4.6, it still hits the same issue.

[betaHi]

thanks, please try the latest version

[LeonarddeR]

Thanks, I think this is now fixed, at least I'm getting response from opus-4.6 and am no longer getting errors related to completions.

[LeonarddeR]

It looks like this issue is back now:

 ERROR  Failed to create chat completions { route: '/chat/completions',                                       09:05:00  
  model: 'claude-opus-4.7',                                                                                             
  status: 400,                                                                                                          
  statusText: 'Bad Request',                                                                                            
  body: 'Bad Request\n',                                                                                                
  request:                                                                                                              
   '{"max_tokens":32000,"message_count":4,"output_config_effort":"xhigh","stream":true,"tools":{"count":40,"invalidNames":["mcp__plugin_microsoft-docs_microsoft-learn__microsoft_code_sample_search","mcp__plugin_microsoft-docs_microsoft-learn__microsoft_docs_search"]}}' }                                                                                         
 

[betaHi]

Thanks for reopening this and for the detailed debug log.

I was able to reproduce the same request shape: this was a regression from the recent Opus 4.7 effort routing change.

I published betahi-copilot-bridge@0.20.12 and also verified the published package with:

npx betahi-copilot-bridge@latest start

please try again.