## Why
`codex-core` currently owns the generic contextual-fragment trait and
several reusable fragment implementations. That makes it harder for
other crates to share the same host-owned model-input abstraction
without depending on all of `codex-core`.
This change extracts the reusable fragment machinery into a small
`codex-context-fragments` crate so future extension and skills work can
depend on the fragment abstraction directly.
## What Changed
- Added the `codex-context-fragments` crate with:
- `ContextualUserFragment`
- `FragmentRegistration` / `FragmentRegistrationProxy`
- additional-context fragment types
- Moved `SkillInstructions` into `codex-core-skills`, since
skill-specific rendering belongs with skills rather than generic core
context machinery.
- Kept `codex-core` re-exporting the fragment types it still uses
internally, so existing call sites keep the same shape.
- Updated Cargo and Bazel workspace metadata for the new crate.
## Verification
- `cargo metadata --locked --format-version 1 --no-deps`
- `just bazel-lock-update`
- `just bazel-lock-check`
## Why
`codex_core` is consistently a bottleneck for incremental builds during
iteration. The simplest fix is to make the crate smaller.
## Summary
`codex-core` owns several reusable prompt renderers and static prompt
assets, which makes the crate harder to split apart.
Rename `codex-review-prompts` to `codex-prompts` and move shared review,
goal, permissions, compaction, realtime, hierarchical AGENTS.md, and
`apply_patch` prompts into it. Move prompt-only tests and update
consumers and `CODEOWNERS`.
## Validation
- `just test -p codex-prompts -p codex-apply-patch`
- `just test -p codex-core prompt_caching`
- Bazel builds for the affected crates
jif ·
Adam Perry @ OpenAI ·