feat: Codex host support

[aanishs]

Summary

• Add --host flag to setup script supporting both claude and codex targets
• Codex gets its own skill directory (~/.codex/skills) with host-appropriate skill files
• Three new test files: generation, setup, and smoke tests for the Codex path

Test plan

• bun test test/codex-generation.test.ts
• bun test test/codex-setup.test.ts
• bun test test/codex-smoke.test.ts
• ./setup --host codex installs to ~/.codex/skills/em-dash
• ./setup --host claude still works as before

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

This PR adds Codex as a supported host target alongside the existing Claude Code path. The setup script gains a --host flag; --host codex migrates any direct Codex install, generates Codex-flavoured skill docs via gen-skill-docs.ts --host codex, builds a ~/.codex/skills/em-dash runtime root with symlinked assets, and links per-skill directories into ~/.codex/skills/. Three test files exercise the generator, the setup script integration, and an optional end-to-end smoke test.

All four issues flagged in the previous review round have been addressed:

• gen-skill-docs.ts now parses --host codex, strips version: / allowed-tools: frontmatter fields, replaces .claude/ paths with .agents/ equivalents, and emits agents/openai.yaml per skill
• CODEX_GENERATED_SKILLS_DIR is recomputed after migrate_direct_codex_install may have moved SOURCE_EMDASH_DIR
• The unused emdash_dir parameter has been removed from link_codex_skill_dirs
• The smoke test now forwards an isolated EMDASH_CODEX_OUTPUT_ROOT to prevent writes into the source tree

One minor issue remains: the dry-run stale-files error message in gen-skill-docs.ts always prints bun run gen:skill-docs regardless of the active host, leaving Codex users with the wrong regeneration command.

Confidence Score: 5/5

PR is safe to merge; all four previously-identified blocking issues are resolved and only a minor UX inaccuracy in the dry-run error message remains

All P1 findings from the prior review round are fully addressed. The sole remaining finding is a P2 UX issue where the dry-run stale-files error message omits --host codex, which does not affect correctness, data integrity, or the actual generation/linking logic.

scripts/gen-skill-docs.ts has the minor dry-run message inaccuracy noted above; no other files require special attention

Important Files Changed

Filename	Overview
setup	Adds --host codex path with migration, runtime root creation, skill linking, and CODEX_GENERATED_SKILLS_DIR recomputation after migration — all previous thread issues are addressed
scripts/gen-skill-docs.ts	Implements --host codex: frontmatter stripping, path replacement, agents/openai.yaml emission, and Codex dry-run support; dry-run stale-files message omits --host codex
test/codex-generation.test.ts	Four generation tests covering output files, frontmatter stripping, dry-run freshness, and empty-root dry-run, all with properly isolated temp dirs
test/codex-setup.test.ts	Two setup integration tests (global and repo-local) with isolated HOME and EMDASH_CODEX_OUTPUT_ROOT env vars
test/codex-smoke.test.ts	Optional end-to-end smoke test gated on CODEX_SMOKE=1; now correctly passes EMDASH_CODEX_OUTPUT_ROOT to avoid writing into the source tree
package.json	Adds the three new Codex test files to the bun test suite so they run in CI

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[setup --host codex] --> B{migrate_direct_codex_install}
    B -->|moved SOURCE_EMDASH_DIR| C[Recompute CODEX_GENERATED_SKILLS_DIR]
    B -->|no migration needed| D[generate_codex_skill_docs]
    C --> D
    D --> E[bun run gen:skill-docs -- --host codex]
    E --> F[Write SKILL.md + agents/openai.yaml\ninto CODEX_OUTPUT_ROOT per skill]
    F --> G{CODEX_REPO_LOCAL?}
    G -->|yes: inside .agents/skills/| H[CODEX_SKILLS = .agents/skills]
    G -->|no: global install| I[create_codex_runtime_root\n~/.codex/skills/em-dash]
    H --> J[link_codex_skill_dirs]
    I --> J
    J --> K[Symlink each skill dir from CODEX_SKILLS]
    K --> L[em-dash ready - codex]

Loading

_{Reviews (4): Last reviewed commit: "fix: implement --host codex in gen-skill..." | Re-trigger Greptile}