Files
codex/codex-rs/tools
Shijie Rao 370b13afc9 Honor client-resolved service tier defaults (#23537)
## Why

Model catalog responses can now advertise a nullable
`default_service_tier` for each model. Codex needs to preserve three
distinct states all the way from config/app-server inputs to inference:

- no explicit service tier, so the client may apply the current model
catalog default when FastMode is enabled
- explicit `default`, meaning the user intentionally wants standard
routing
- explicit catalog tier ids such as `priority`, `flex`, or future tiers

Keeping those states distinct prevents the UI from showing one tier
while core sends another, especially after model switches or app-server
`thread/start` / `turn/start` updates.

## What Changed

- Plumbed `default_service_tier` through model catalog protocol types,
app-server model responses, generated schemas, model cache fixtures, and
provider/model-manager conversions.
- Added the request-only `default` service tier sentinel and normalized
legacy config spelling so `fast` in `config.toml` still materializes as
the runtime/request id `priority`.
- Moved catalog default resolution to the TUI/client side, including
recomputing the effective service tier when model/FastMode-dependent
surfaces change.
- Updated app-server thread lifecycle config construction so
`serviceTier: null` preserves explicit standard-routing intent by
mapping to `default` instead of internal `None`.
- Kept core responsible for validating explicit tiers against the
current model and stripping `default` before `/v1/responses`, without
applying catalog defaults itself.

## Validation

- `CARGO_INCREMENTAL=0 cargo build -p codex-cli`
- `CARGO_INCREMENTAL=0 cargo test -p codex-app-server model_list`
- `cargo test -p codex-tui service_tier`
- `cargo test -p codex-protocol service_tier_for_request`
- `cargo test -p codex-core get_service_tier`
- `RUST_MIN_STACK=8388608 CARGO_INCREMENTAL=0 cargo test -p codex-core
service_tier`
2026-05-20 15:57:50 -07:00
..

codex-tools

codex-tools is the shared support crate for building, adapting, and executing model-visible tools outside codex-core.

Today this crate owns the host-facing tool models and helpers that no longer need to live in core/src/tools/spec.rs or core/src/client_common.rs:

  • aggregate host models such as ToolSpec, ConfiguredToolSpec, LoadableToolSpec, ResponsesApiNamespace, and ResponsesApiNamespaceTool
  • host discovery models used while assembling tool sets, including discoverable-tool models and request-plugin-install helpers
  • host adapters such as schema sanitization, MCP/dynamic conversion, code-mode augmentation, and image-detail normalization
  • shared executable-tool contracts such as ToolExecutor, ToolCall, and ToolOutput

That extraction is the first step in a longer migration. The goal is not to move all of core/src/tools into this crate in one shot. Instead, the plan is to peel off reusable pieces in reviewable increments while keeping compatibility-sensitive orchestration in codex-core until the surrounding boundaries are ready.

Vision

Over time, this crate should hold host-side tool machinery that is shared by multiple consumers, for example:

  • host-visible aggregate tool models
  • tool-set planning and discovery helpers
  • MCP and dynamic-tool adaptation into Responses API shapes
  • code-mode compatibility shims that do not depend on codex-core
  • other narrowly scoped host utilities that multiple crates need

The corresponding non-goals are just as important:

  • do not move codex-core orchestration here prematurely
  • do not pull Session / TurnContext / approval flow / runtime execution logic into this crate unless those dependencies have first been split into stable shared interfaces
  • do not turn this crate into a grab-bag for unrelated helper code

Migration approach

The expected migration shape is:

  1. Keep extension-owned executable-tool authoring in codex-extension-api.
  2. Move host-side planning/adaptation helpers here when they no longer need to stay coupled to codex-core.
  3. Leave compatibility-sensitive adapters in codex-core while downstream call sites are updated.
  4. Only extract higher-level host infrastructure after the crate boundaries are clear and independently testable.

Crate conventions

This crate should start with stricter structure than core/src/tools so it stays easy to grow:

  • src/lib.rs should remain exports-only.
  • Business logic should live in named module files such as foo.rs.
  • Unit tests for foo.rs should live in a sibling foo_tests.rs.
  • The implementation file should wire tests with:
#[cfg(test)]
#[path = "foo_tests.rs"]
mod tests;

If this crate starts accumulating code that needs runtime state from codex-core, that is a sign to revisit the extraction boundary before adding more here.