fix(codex): omit collaboration mode until a model is known

[Slowper]

What changed

turn/start no longer sends collaborationMode when no model has been selected. A selected model still sends the same mode, effort, and built-in instructions as before. A plan turn with no model still uses the read-only sandbox and approvalPolicy: "never".

Why

Codex 0.160 rejects the turn before it starts:

Invalid request: invalid type: null, expected a string

collaborationMode.settings.model is a required string. Sending null is that error. Omitting the field is missing field model. Reproduced against codex app-server 0.160.0: a thread starts and Codex chooses the model, then turn/start with settings.model: null fails immediately. The same request with the model omitted from collaborationMode, or with settings.model set to a real model id, is accepted. reasoning_effort: null and developer_instructions: null are fine once model is a string.

UI

No layout changes. A Codex turn that previously failed with no reply now starts.

Validation

• npm test — 4261 passed, 13 skipped
• npx tsc --noEmit
• npm run test:host and npm run host:package on Node 24.21.0 (the host job's Node version). Node 20 cannot load node:sqlite, which the host job does not use.
• cargo fmt --check
• cargo clippy --workspace --all-targets -- -D warnings
• cargo check
• cargo test — 539 passed, 1 ignored

Checklist

• I ran npm run check (web and Rust steps, matching CI)
• This PR is small and focused
• I did not mix unrelated changes

Made with Cursor

Summary by CodeRabbit

• Bug Fixes
  • Codex requests now omit model settings when no model is specified, preventing blank model values from being sent.
  • Plan turns continue to use read-only sandbox settings and never request approval when the model is blank.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: Repository UI
• Review profile: CHILL
• Plan: Advanced
• Run ID: 654e1ad9-8169-4c56-8cb1-e66ca047462e

📥 Commits

Reviewing files that changed from the base of the PR and between 98da85a and 4d289eb.

📒 Files selected for processing (2)

• src/integrations/harness/providers/codex/codexProtocol.test.ts
• src/integrations/harness/providers/codex/codexProtocol.ts

Included review availability: This review used your included allowance. Your plan provides up to 8 included reviews per hour; 7 remain after this review.

---

📝 Walkthrough

Walkthrough

The Codex turn parameter builder now trims the model value and omits model and collaborationMode when it is empty. Tests cover empty-model behavior for standard and plan turns.

Changes

Codex turn parameters

Layer / File(s)	Summary
Conditional model fields src/integrations/harness/providers/codex/codexProtocol.ts, src/integrations/harness/providers/codex/codexProtocol.test.ts	The builder trims the model and includes model and collaborationMode only when the trimmed value is nonempty. Tests check empty-model parameters and verify that plan turns retain a read-only sandbox and approvalPolicy: "never".

Priority: ➖ Normal

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Suggested reviewers: sambhavthakkar

Merge Risk: 🔵 Low · up to 4d289

A model-less planning side answer may lack the Plan instruction preset, though edits remain blocked. This is a bounded behavior issue that can be accepted or addressed separately.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 2 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main change: omitting collaboration mode until a model is known.
Description check	✅ Passed	The description covers what changed, why, UI impact, validation, and all checklist items required by the template.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

• Fix all pre-merge checks with AI

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create a new PR

• Autopilot · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}