[echarrod]

Description

Refs #2654. Follow-up to #4919 (Claude) and #5116 (Droid).

Adds a Codex CLI-only integration option:

specify init my-project --integration codex --integration-options="--no-model-invocation"

• It writes agents/openai.yaml with policy.allow_implicit_invocation: false next to each core speckit-* command skill. OpenAI's skills docs say Codex then does not invoke the skill implicitly, while explicit $skill invocation still works. The default is unchanged.
• Extension skills stay model-invocable, because mandatory hooks such as git's speckit.git.feature need the model to invoke them.
• The option persists through integration.json, so specify integration upgrade codex reapplies it, and clearing the options removes the generated files (they are tracked in the integration manifest).

Differences from Droid:

• Codex has no SKILL.md frontmatter flag, so the policy is a separate file. The integration overrides setup() to write it after the skills, and an existing agents/openai.yaml keeps its other keys.
• Because it is a sibling file, preset overrides of core skills leave it in place; skills registered by commands that bypass setup() get no file until specify integration upgrade codex --force.
• The docs do not say whether a skill with this policy keeps its name and description in Codex's context, so the new docs section only claims implicit invocation is disabled.

Only the Codex package, its tests and docs/integrations/codex.md change; no shared base.py change.

AI Disclosure

• I did not use AI assistance for this contribution
• I did use AI assistance (fill in the disclosure below)

AI disclosure: Written for @echarrod by Claude Code (claude-sonnet-5-5) running autonomously. It wrote the code, tests and docs, ran the test suite and an automated /code-review medium. @echarrod reviewed it before marking it ready.

[Copilot]

🟡 Changes recommended

Policy-file handling can destroy user configuration and leave implicit invocation disabled after the option is cleared.

4 open issues

• Reject unreadable or invalid openai.yaml before overwriting · New
• Preserve user settings during openai.yaml cleanup · New
• Prevent symlink writes outside the project · New
• Reconcile managed policies when disabling implicit invocation · New

What changed in this PR

Adds a Codex-specific opt-out for implicit invocation of core Spec Kit skills, following the Claude and Droid integration options.

Changes:

• Adds --no-model-invocation and generates per-skill agents/openai.yaml policies.
• Keeps extension skills unchanged and uses existing option persistence and manifest tracking.
• Adds tests and documents usage, upgrades, and lifecycle limitations.

Validation used targeted, dependency-free checks; the project test suite was not run.

AI-generated review by GitHub Copilot for the requesting reviewer (identity not provided; model unknown; automated mode; settings not exposed).

File	Description
tests/​integrations/​test_integration_codex.py	Tests option parsing, policy generation, upgrades, extension exclusion, and metadata merging.
src/​specify_cli/​integrations/​codex/​__init__.py	Declares the option and writes tracked policy files for core skills.
docs/​integrations/​codex.md	Documents invocation behavior, persistence, and lifecycle caveats.

_{Review effort: Max}

[mnriem]

Please address Copilot feedback

[echarrod]

@mnriem I've addressed the Copilot feedback in c409bf2, 06cafd3 and 4788fbd (Codex package, its tests and docs/integrations/codex.md only):

• An existing agents/openai.yaml that cannot be read or parsed, or that has a non-mapping root or a non-mapping policy, now stops setup with an error naming the file. This happens before any skill is written, and the file's bytes are left unchanged.
• Policy files are written with manifest.record_file() on the lexical project-relative path. A symlinked file or agents/ directory is now refused before anything is written outside the project.
• Pre-existing or user-edited files are recorded as partial and keep that ownership across upgrades. Uninstall, option-clearing upgrades and re-running init without the option remove only the managed policy from them, and delete only generated files whose content is unchanged.
• setup() reconciles against the prior on-disk manifest, so re-init without the option no longer leaves implicit invocation disabled or the files untracked.

Each case has a regression test that fails on 8c4c5bb and passes now: 20 new tests, 68 in tests/integrations/test_integration_codex.py. Full suite: 12830 passed, 434 skipped, 0 failed.

AI disclosure: posted on behalf of @echarrod by Claude Code (model: claude-opus-5-5, autonomous mode). The agent wrote the changes and tests, ran the test suite and two automated code-review passes, and wrote this comment. The earlier commit 8c4c5bb carries an Assisted-by: trailer without the autonomous/supervised mode; it was autonomous and is covered by this disclosure.