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codex/codex-rs/core/src/config_loader
T
Michael Bolin 577a416f9a Extract codex-config from codex-core (#11389)
`codex-core` had accumulated config loading, requirements parsing,
constraint logic, and config-layer state handling in a single crate.
This change extracts that subsystem into `codex-config` to reduce
`codex-core` rebuild/test surface area and isolate future config work.

## What Changed

### Added `codex-config`

- Added new workspace crate `codex-rs/config` (`codex-config`).
- Added workspace/build wiring in:
  - `codex-rs/Cargo.toml`
  - `codex-rs/config/Cargo.toml`
  - `codex-rs/config/BUILD.bazel`
- Updated lockfiles (`codex-rs/Cargo.lock`, `MODULE.bazel.lock`).
- Added `codex-core` -> `codex-config` dependency in
`codex-rs/core/Cargo.toml`.

### Moved config internals from `core` into `config`

Moved modules to `codex-rs/config/src/`:

- `core/src/config/constraint.rs` -> `config/src/constraint.rs`
- `core/src/config_loader/cloud_requirements.rs` ->
`config/src/cloud_requirements.rs`
- `core/src/config_loader/config_requirements.rs` ->
`config/src/config_requirements.rs`
- `core/src/config_loader/fingerprint.rs` -> `config/src/fingerprint.rs`
- `core/src/config_loader/merge.rs` -> `config/src/merge.rs`
- `core/src/config_loader/overrides.rs` -> `config/src/overrides.rs`
- `core/src/config_loader/requirements_exec_policy.rs` ->
`config/src/requirements_exec_policy.rs`
- `core/src/config_loader/state.rs` -> `config/src/state.rs`

`codex-config` now re-exports this surface from `config/src/lib.rs` at
the crate top level.

### Updated `core` to consume/re-export `codex-config`

- `core/src/config_loader/mod.rs` now imports/re-exports config-loader
types/functions from top-level `codex_config::*`.
- Local moved modules were removed from `core/src/config_loader/`.
- `core/src/config/mod.rs` now re-exports constraint types from
`codex_config`.
577a416f9a · 2026-02-11 10:02:49 -08:00
History
..

codex-core config loader

This module is the canonical place to load and describe Codex configuration layers (user config, CLI/session overrides, managed config, and MDM-managed preferences) and to produce:

  • An effective merged TOML config.
  • Per-key origins metadata (which layer “wins” for a given key).
  • Per-layer versions (stable fingerprints) used for optimistic concurrency / conflict detection.

Public surface

Exported from codex_core::config_loader:

  • load_config_layers_state(codex_home, cwd_opt, cli_overrides, overrides, cloud_requirements) -> ConfigLayerStack
  • ConfigLayerStack
    • effective_config() -> toml::Value
    • origins() -> HashMap<String, ConfigLayerMetadata>
    • layers_high_to_low() -> Vec<ConfigLayer>
    • with_user_config(user_config) -> ConfigLayerStack
  • ConfigLayerEntry (one layers {name, config, version, disabled_reason}; name carries source metadata)
  • LoaderOverrides (test/override hooks for managed config sources)
  • merge_toml_values(base, overlay) (public helper used elsewhere)

Layering model

Precedence is top overrides bottom:

  1. MDM managed preferences (macOS only)
  2. System managed config (e.g. managed_config.toml)
  3. Session flags (CLI overrides, applied as dotted-path TOML writes)
  4. User config (config.toml)

Layers with a disabled_reason are still surfaced for UI, but are ignored when computing the effective config and origins metadata. This is what ConfigLayerStack::effective_config() implements.

Typical usage

Most callers want the effective config plus metadata:

use codex_core::config_loader::{load_config_layers_state, LoaderOverrides};
use codex_utils_absolute_path::AbsolutePathBuf;
use toml::Value as TomlValue;

let cli_overrides: Vec<(String, TomlValue)> = Vec::new();
let cwd = AbsolutePathBuf::current_dir()?;
let layers = load_config_layers_state(
    &codex_home,
    Some(cwd),
    &cli_overrides,
    LoaderOverrides::default(),
    None,
).await?;

let effective = layers.effective_config();
let origins = layers.origins();
let layers_for_ui = layers.layers_high_to_low();

Internal layout

Implementation is split by concern:

  • state.rs: public types (ConfigLayerEntry, ConfigLayerStack) + merge/origins convenience methods.
  • layer_io.rs: reading config.toml, managed config, and managed preferences inputs.
  • overrides.rs: CLI dotted-path overrides → TOML “session flags” layer.
  • merge.rs: recursive TOML merge.
  • fingerprint.rs: stable per-layer hashing and per-key origins traversal.
  • macos.rs: managed preferences integration (macOS only).