openclaw - 💡(How to fix) Fix [Bug]: 2026.5.27+ Codex harness rejects openai/gpt-5.5 after upgrade from 2026.5.26

Bug type

Regression (worked before, now fails)

Beta release blocker

No

Summary

After upgrading OpenClaw from 2026.5.26 to 2026.5.27, all agent execution began failing with the following runtime error:

Requested agent harness "codex" does not support openai/gpt-5.5 (provider is not one of: codex)

The issue persists in 2026.5.28.

This appears to be related to the recent openai-codex/* → openai/* routing migration and Codex harness validation logic.

Environment

• OS: Ubuntu Linux
• Install method: npm global install
• Node version: v22.22.2
• OpenClaw versions tested:
• 2026.5.26 → WORKING
• 2026.5.27 → BROKEN
• 2026.5.28 → STILL BROKEN
• Auth method:
• ChatGPT/Codex Browser OAuth login

Exact Error ⚠️ Agent failed before reply: Requested agent harness "codex" does not support openai/gpt-5.5 (provider is not one of: codex). Logs: openclaw logs --follow

Steps to reproduce

Reproduction

1. Install/update OpenClaw to 2026.5.27 or 2026.5.28
2. Configure model as:
3. openai/gpt-5.5
4. Authenticate using:
5. openai-codex OAuth login
6. Open Control UI
7. Start new session with default main agent
8. Send any message (example: hello)

Result:

Gateway/UI/auth all work Session initializes Agent execution fails immediately with the Codex harness validation error above

Important Observations

• 2026.5.26 worked normally before upgrade
• Failure began immediately after upgrading to 2026.5.27
• 2026.5.28 did not resolve the issue
• Gateway itself is healthy
• UI works
• Token auth works
• OAuth succeeds
• Sessions are created normally
• Failure occurs only at runtime execution stage

Troubleshooting Already Attempted

Tried all of the following without success:

• openclaw doctor
• openclaw doctor --fix
• openclaw models auth login --provider openai-codex
• multiple gateway restarts
• new browser sessions
• new OpenClaw sessions
• downgrade to 2026.5.26
• re-upgrade to 2026.5.28
• refresh OAuth tokens
• regenerate gateway tokens
• recreate dashboard sessions

Observed behavior remained unchanged.

Additional Notes

The issue appears related to recent Codex/OpenAI routing migration work.

Current docs appear to indicate that this configuration should be valid:

{ "model": "openai/gpt-5.5", "agentRuntime": { "id": "codex" } }

However, runtime validation rejects the configuration with the error shown above.

Potentially related issues:

#78407 #79978 #82368

This may be a regression in Codex harness provider validation introduced in 2026.5.27.

Expected behavior

prompt: hello response: hi there

Actual behavior

Requested agent harness "codex" does not support openai/gpt-5.5 (provider is not one of: codex).

⚠️ Agent failed before reply: Requested agent harness "codex" does not support openai/gpt-5.5 (provider is not one of: codex). Logs: openclaw logs --follow

OpenClaw version

2026.5.28

Operating system

Ubuntu 24.04

Install method

npm global

Model

openai/gpt-5.5

Provider / routing chain

OpenClaw Control UI → local OpenClaw gateway (127.0.0.1:18789) → main agent → Codex harness / app-server runtime → OpenAI Codex OAuth auth profile → model route openai/gpt-5.5. No external proxy or custom model router. Installed via npm global package. Gateway runs as a user systemd service.

Additional provider/model setup details

No response

Logs, screenshots, and evidence

Impact and severity

cannot interact with agent

Additional information

No response