Compaction auto not working with Codex

[brandon93s]

Description

I've this this a few times now running long sessions:

{"type":"error","sequence_number":2,"error":{"type":"invalid_request_error","code":"context_length_exceeded","message":"Your input exceeds the context window of this model. Please adjust your input and try again.","param":"input"}}

I'm using GPT-5.2 Codex via OpenAI OAuth. Ideally codex's auto-compation would work, but in the absence of that I thought the opencode auto compaction would run before the error is triggered. I've set this explicitly in my config:

  "compaction": {
    "auto": true,
    "prune": true,
  },

Plugins

none

OpenCode version

1.1.18

Steps to reproduce

No response

Screenshot and/or share link

Operating System

macOS 15.6.1

Terminal

ghostty

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Auto-compaction enabled by default, but context_length_exceeded errors still occur in agent workflows #8089: Auto-compaction enabled by default, but context_length_exceeded errors still occur in agent workflows
• [BUG]: Auto compaction not triggering reliably with Anthropic models #6068: [BUG]: Auto compaction not triggering reliably with Anthropic models
• Compaction Failing to Run on Time #6286: Compaction Failing to Run on Time
• Feature Request: Configurable context limit and auto-compaction threshold #8140: Feature Request: Configurable context limit and auto-compaction threshold

Feel free to ignore if none of these address your specific case.