hermes - 💡(How to fix) Fix bug: openai-codex provider — TypeError: 'NoneType' object is not iterable on every request (gpt-5.5)

Bug Report

Provider: openai-codex Model: gpt-5.5 Endpoint: https://chatgpt.com/backend-api/codex Auth mode: chatgpt (OAuth device flow)

Description

After a successful OAuth authentication via hermes model → OpenAI Codex device flow, every API call to the openai-codex provider fails immediately with:

TypeError: 'NoneType' object is not iterable

The error is classified as non-retryable (HTTP None) and the agent falls back to the configured fallback model on every request. The OAuth token is valid and fresh — hermes doctor reports ✓ OpenAI Codex auth (logged in) and last_refresh in auth.json is current.

Log output

WARNING agent.conversation_loop: API call failed (attempt 1/3) error_type=TypeError
  provider=openai-codex
  base_url=https://chatgpt.com/backend-api/codex
  model=gpt-5.5
  summary='NoneType' object is not iterable
Non-retryable error (HTTP None) — trying fallback...
Primary model failed — switching to fallback

The same error appears in cron job sessions too, so it is not specific to interactive use.

Steps to reproduce

1. Configure config.yaml with provider: openai-codex, model: gpt-5.5
2. Authenticate via hermes model → OpenAI Codex → complete device flow in browser
3. Verify auth: hermes doctor → should show ✓ OpenAI Codex auth (logged in)
4. Run: hermes chat -q "say hi"
5. Expected: Response via gpt-5.5 using ChatGPT Plus/Pro subscription
6. Actual: TypeError: 'NoneType' object is not iterable, immediate fallback

Auth store state

~/.hermes/auth.json → providers.openai-codex:

• auth_mode: chatgpt
• tokens: contains access_token + refresh_token
• last_refresh: timestamp of today (re-authed fresh, same result)

Environment

• OS: macOS 26.3
• Hermes version: commit d61785889 (latest main as of 2026-05-28)
• Python: 3.11
• First observed: 2026-05-27 in cron logs, still reproducible 2026-05-28

Notes

The HTTP None status in the non-retryable error path suggests the response object is None or the streaming response is not structured as expected — possibly the chatgpt.com/backend-api/codex endpoint has changed its response format, or the Bearer token format is no longer accepted. The error surfaces in the codex_responses streaming path in agent/conversation_loop.py.