feat: Add support for Codex

[glemaitre]

Add support for the codex harness

requires https://github.com/probabl-ai/skore-hub/pull/1754

[rouk1]

Now that response api is merge this is ready !

[rouk1]

I updated this PR to ensure existing codex configuration is not override by the command.

@thomass-dev may I ask for a review ?

[thomass-dev]

Cursor review

Blocker: merge still hijacks the global default

The latest commit says existing Codex config is not fully overwritten. Other providers are kept, but every configure/launch still sets user-level:

• model = "skore-agent"
• model_provider = "skore"
  The CLI even prints that plain codex now defaults to Skore in every project. That is a global default change, not a merge of a provider. Anyone who uses Codex with OpenAI/OpenRouter elsewhere will get Skore until they edit
  ~/.codex/config.toml again — and the next skore agent will put it back.
  If the product intent is “add Skore, leave my default alone”, stop writing those two root keys (or restore them after the session). If the intent is “this command makes Codex use Skore”, keep the write but make the warning much
  louder; the commit message currently oversells what merge does.

Other issues

TOML is string-patched, not parsed. _CODEX_PROVIDER_SECTION and _set_toml_root_string work for the files this code writes. They will mis-handle nested tables under [model_providers.skore], quoted keys, or an API key
containing ". Copilot went the parse-and-rewrite route; Codex should too if you keep mutating user config.
_launch_codex is less defensive than Copilot. Missing project file is handled; corrupt project TOML raises tomllib.TOMLDecodeError instead of a RuntimeError with a “run skore agent first” hint.
Launch ignores project model. It re-syncs with the model_id argument, not .codex/skore-provider.toml. Fine today (skore-agent everywhere), brittle if those ever diverge.
Secrets live in ~/.codex/config.toml. Justified by Codex’s env_key behavior, and the project copy is gitignored. Still a durable hub key in a user file that is not removed on exit.
History. Two _ commits plus a Copilot upsert in the same Codex PR. Squash (or split Copilot) before merge.
Repo .gitignore. Adds .skore, opencode.json, Copilot/Pi/Codex byproducts. Useful for dogfooding this repo, not required for the feature.

Verdict

Feature direction matches Copilot’s constraints. I would not merge until you decide whether model / model_provider should be rewritten globally — that is the real behavior change, and it contradicts the “do not override” commit. After that, parse TOML instead of regex, and squash the _ commits.

[thomass-dev]

Check my previous comment

[rouk1]

New design: fully project-local
The ~/.codex/skore.config.toml profile is gone (it was still one user-level file shared across worktrees). Now:

• Configure writes only .codex/skore-provider.toml in the workspace (gitignored) — nothing outside the project is ever read or written, so every worktree carries its own model/URL/key.
• Launch passes the provider to Codex as runtime --config overrides (src/skore_cli/agent/_harnesses.py:275):

codex --model <project-model> \
  --config model_provider="skore" \
  --config model_providers.skore.name="Skore Agent" \
  --config model_providers.skore.base_url="…" \
  --config model_providers.skore.wire_api="responses" \
  --config 'model_providers.skore.env_http_headers={ "X-API-Key" = "SKORE_AGENT_API_KEY" }'

with SKORE_AGENT_API_KEY set only in the exec'd process env.
Why this works (verified in the Codex Rust source):

• Project files can't declare model_providers (PROJECT_LOCAL_CONFIG_DENYLIST), but runtime --config layers sit above user config and can (ArgAction::Append, dotted paths, TOML values — utils/cli/src/config_override.rs).
• env_http_headers maps header → env var read at request time (model-provider-info/src/lib.rs:274) — the key never lands on the command line (ps-safe).
• Overrides insert leaf keys, so a user's own providers in config.toml survive untouched (config/src/overrides.rs).
  Named SKORE_AGENT_API_KEY to avoid colliding with the CLI's existing SKORE_HUB_API_KEY (src/skore_cli/_hub_auth.py:12). Tests assert the overrides parse as valid TOML, the raw key is absent from argv, and no ~/.codex path is ever created.

[thomass-dev]

Could you please fix the merge-conflict?

[rouk1]

Could you please fix the merge-conflict?

Done!