How-To Guide
Fix Copilot-ACP Connection Issues in Hermes
Resolve common Copilot-ACP authentication and model errors when using GitHub Copilot as a provider in Hermes Agent.
Quick answer
Copilot-ACP authentication failures in Hermes are usually an auxiliary-model problem. The common fix is switching your aux model away from Qwen to MiMo (or another stable model). If auth still fails, re-check the Copilot provider credentials and the aux model configuration.
Copilot-ACP integration can encounter authentication issues, especially with certain auxiliary model configurations. The most common fix is changing your aux model from Qwen to MiMo or another model.
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Before you start:
- ☑Hermes Agent installed
- ☑GitHub CLI (gh) installed and authenticated
- ☑GitHub Copilot subscription active
Steps
- 1
Check the error logs
Look in ~/.hermes/logs/agent.log for 'unhandled auth_type external_process for copilot-acp' warnings
- 2
Set a different aux model
In config.yaml, set the auxiliary model to something other than Qwen — try MiMo or another stable model
- 3
Verify gh auth status
Run 'gh auth status' to ensure GitHub CLI is properly authenticated with Copilot access
- 4
Update Hermes
Run 'hermes update' — Copilot-ACP bugs are frequently patched
- 5
Check provider fallback
Ensure you have a fallback provider configured in case Copilot-ACP fails
Pro Tips
- 💡The aux model setting at agent.auxiliary_models in config.yaml controls which model handles lightweight tasks — Qwen has been causing issues with Copilot-ACP
- 💡Check the Hermes Discord for real-time updates on provider issues — Copilot-ACP problems are usually discussed within hours
- 💡Having a fallback provider like OpenRouter prevents complete downtime when one provider has issues
Troubleshooting
❌ 'CopilotACPClient' object has no attribute 'responses'
✅ This is a known bug with certain Copilot-ACP versions. Update Hermes to the latest version and change the aux model to MiMo.
❌ Context length detection failing for Copilot models
✅ Set model.context_length explicitly in config.yaml to override the auto-detection: model: context_length: 128000
❌ Falling back to gh auth instead of staying on copilot-acp
✅ Check ~/.hermes/logs/gateway.log for the specific auth failure. Often requires re-running 'gh auth login' with Copilot scope.
FAQ
How do I fix Copilot-ACP auth errors in Hermes?
Most often, change your auxiliary model from Qwen to MiMo or another stable model — Copilot-ACP is sensitive to certain aux configurations. Then re-verify the Copilot provider credentials.
Why does the auxiliary model affect Copilot-ACP?
Hermes uses an aux model for secondary tasks, and some combinations trip up the Copilot-ACP integration's auth. Xiaomi MiMo is a frequently recommended stable alternative.
What if changing the aux model doesn't help?
Re-check the Copilot provider setup and tokens, and confirm your Copilot subscription is active, since ACP relies on that allocation.