Commit Graph
268 Commits
Author SHA1 Message Date
iceweasel-oai 307e427a9b don't include redundant write roots in apply_patch (#16030)
apply_patch sometimes provides additional parent dir as a writable root
when it is already writable. This is mostly a no-op on Mac/Linux but
causes actual ACL churn on Windows that is best avoided. We are also
seeing some actual failures with these ACLs in the wild, which I haven't
fully tracked down, but it's safe/best to avoid doing it altogether.
2026-03-27 15:41:51 -07:00
Michael Bolin 16d4ea9ca8 codex-tools: extract responses API tool models (#16031)
## Why

The previous extraction steps moved shared tool-schema parsing into
`codex-tools`, but `codex-core` still owned the generic Responses API
tool models and the last adapter layer that turned parsed tool
definitions into `ResponsesApiTool` values.

That left `core/src/tools/spec.rs` and `core/src/client_common.rs`
holding a chunk of tool-shaping code that does not need session state,
runtime plumbing, or any other `codex-core`-specific dependency. As a
result, `codex-tools` owned the parsed tool definition, but `codex-core`
still owned the generic wire model that those definitions are converted
into.

This change moves that boundary one step further. `codex-tools` now owns
the reusable Responses/tool wire structs and the shared conversion
helpers for dynamic tools, MCP tools, and deferred MCP aliases.
`codex-core` continues to own `ToolSpec` orchestration and the remaining
web-search-specific request shapes.

## What changed

- added `tools/src/responses_api.rs` to own `ResponsesApiTool`,
`FreeformTool`, `ToolSearchOutputTool`, namespace output types, and the
shared `ToolDefinition -> ResponsesApiTool` adapter helpers
- added `tools/src/responses_api_tests.rs` for deferred-loading
behavior, adapter coverage, and namespace serialization coverage
- rewired `core/src/tools/spec.rs` to use the extracted dynamic/MCP
adapter helpers instead of defining those conversions locally
- rewired `core/src/tools/handlers/tool_search.rs` to use the extracted
deferred MCP adapter and namespace output types directly
- slimmed `core/src/client_common.rs` so it now keeps `ToolSpec` and the
web-search-specific wire types, while reusing the extracted tool models
from `codex-tools`
- moved the extracted seam tests out of `core` and updated
`codex-rs/tools/README.md` plus `tools/src/lib.rs` to reflect the
expanded `codex-tools` boundary

## Test plan

- `cargo test -p codex-tools`
- `cargo test -p codex-core --lib tools::spec::`
- `cargo test -p codex-core --lib tools::handlers::tool_search::`
- `just fix -p codex-tools -p codex-core`
- `just argument-comment-lint`

## References

- [#15923](https://github.com/openai/codex/pull/15923) `codex-tools:
extract shared tool schema parsing`
- [#15928](https://github.com/openai/codex/pull/15928) `codex-tools:
extract MCP schema adapters`
- [#15944](https://github.com/openai/codex/pull/15944) `codex-tools:
extract dynamic tool adapters`
- [#15953](https://github.com/openai/codex/pull/15953) `codex-tools:
introduce named tool definitions`
2026-03-27 14:26:54 -07:00
jif-oaiandCodex 426f28ca99 feat: spawn v2 as inter agent communication (#15985)
Co-authored-by: Codex <noreply@openai.com>
2026-03-27 15:45:19 +01:00
jif-oai 6a0c4709ca feat: spawn v2 make task name as mandatory (#15986) 2026-03-27 11:30:22 +01:00
Michael Bolin e6e2999209 permissions: remove macOS seatbelt extension profiles (#15918)
## Why

`PermissionProfile` should only describe the per-command permissions we
still want to grant dynamically. Keeping
`MacOsSeatbeltProfileExtensions` in that surface forced extra macOS-only
approval, protocol, schema, and TUI branches for a capability we no
longer want to expose.

## What changed

- Removed the macOS-specific permission-profile types from
`codex-protocol`, the app-server v2 API, and the generated
schema/TypeScript artifacts.
- Deleted the core and sandboxing plumbing that threaded
`MacOsSeatbeltProfileExtensions` through execution requests and seatbelt
construction.
- Simplified macOS seatbelt generation so it always includes the fixed
read-only preferences allowlist instead of carrying a configurable
profile extension.
- Removed the macOS additional-permissions UI/docs/test coverage and
deleted the obsolete macOS permission modules.
- Tightened `request_permissions` intersection handling so explicitly
empty requested read lists are preserved only when that field was
actually granted, avoiding zero-grant responses being stored as active
permissions.
2026-03-26 17:12:45 -07:00
jif-oai 970386e8b2 fix: root as std agent (#15881) 2026-03-26 18:57:34 +01:00
jif-oai 352f37db03 fix: max depth agent still has v2 tools (#15880) 2026-03-26 17:36:12 +01:00
jif-oai 4a5635b5a0 feat: clean spawn v1 (#15861)
Avoid the usage of path in the v1 spawn
2026-03-26 15:01:00 +01:00
jif-oai b00a05c785 feat: drop artifact tool and feature (#15851) 2026-03-26 13:21:24 +01:00
viyatb-oaiandMichael Bolin 937cb5081d fix: fix old system bubblewrap compatibility without falling back to vendored bwrap (#15693)
Fixes #15283.

## Summary
Older system bubblewrap builds reject `--argv0`, which makes our Linux
sandbox fail before the helper can re-exec. This PR keeps using system
`/usr/bin/bwrap` whenever it exists and only falls back to vendored
bwrap when the system binary is missing. That matters on stricter
AppArmor hosts, where the distro bwrap package also provides the policy
setup needed for user namespaces.

For old system bwrap, we avoid `--argv0` instead of switching binaries:
- pass the sandbox helper a full-path `argv0`,
- keep the existing `current_exe() + --argv0` path when the selected
launcher supports it,
- otherwise omit `--argv0` and re-exec through the helper's own
`argv[0]` path, whose basename still dispatches as
`codex-linux-sandbox`.

Also updates the launcher/warning tests and docs so they match the new
behavior: present-but-old system bwrap uses the compatibility path, and
only absent system bwrap falls back to vendored.

### Validation

1. Install Ubuntu 20.04 in a VM
2. Compile codex and run without bubblewrap installed - see a warning
about falling back to the vendored bwrap
3. Install bwrap and verify version is 0.4.0 without `argv0` support
4. run codex and use apply_patch tool without errors

<img width="802" height="631" alt="Screenshot 2026-03-25 at 11 48 36 PM"
src="https://github.com/user-attachments/assets/77248a29-aa38-4d7c-9833-496ec6a458b8"
/>
<img width="807" height="634" alt="Screenshot 2026-03-25 at 11 47 32 PM"
src="https://github.com/user-attachments/assets/5af8b850-a466-489b-95a6-455b76b5050f"
/>
<img width="812" height="635" alt="Screenshot 2026-03-25 at 11 45 45 PM"
src="https://github.com/user-attachments/assets/438074f0-8435-4274-a667-332efdd5cb57"
/>
<img width="801" height="623" alt="Screenshot 2026-03-25 at 11 43 56 PM"
src="https://github.com/user-attachments/assets/0dc8d3f5-e8cf-4218-b4b4-a4f7d9bf02e3"
/>

---------

Co-authored-by: Michael Bolin <mbolin@openai.com>
2026-03-25 23:51:39 -07:00
Andrei Eternal c4d9887f9a [hooks] add non-streaming (non-stdin style) shell-only PostToolUse support (#15531)
CHAINED PR - note that base is eternal/hooks-pretooluse-bash, not main
-- so the following PR should be first

Matching post-tool hook to the pre-tool functionality here:
https://github.com/openai/codex/pull/15211

So, PreToolUse calls for plain shell calls, allows blocking. This
PostToolUse call runs after the command executed

example run:

```
› as a test, run in parallel the following commands:
  - echo 'one'
  - echo '[block-pre-tool-use]'
  - echo '[block-post-tool-use]'


⚠ MCP startup incomplete (failed: notion, linear)

• Cruising through those three commands in parallel now, and I’ll share the exact outputs right after
  they land.

• Running PreToolUse hook: checking the observatory runes

• Running PreToolUse hook: checking the observatory runes

• Running PreToolUse hook: checking the observatory runes

PreToolUse hook (blocked)
  warning: wizard-tower PreToolUse demo blocked a Bash command on purpose.
  feedback: PreToolUse demo blocked the command. Remove [block-pre-tool-use] to continue.

PreToolUse hook (completed)
  warning: wizard-tower PreToolUse demo inspected Bash: echo 'one'

PreToolUse hook (completed)
  warning: wizard-tower PreToolUse demo inspected Bash: echo '[block-post-tool-use]'

• Ran echo '[block-post-tool-use]'
  └ [block-post-tool-use]

• Ran echo 'one'
  └ one

• Running PostToolUse hook: reading the observatory aftermath

• Running PostToolUse hook: reading the observatory aftermath

PostToolUse hook (blocked)
  warning: wizard-tower PostToolUse demo blocked the Bash follow-through on purpose.
  feedback: PostToolUse demo blocked the result after execution. Remove [block-post-tool-use] to
continue.

PostToolUse hook (completed)
  warning: wizard-tower PostToolUse demo inspected Bash: echo 'one'
  hook context: PostToolUse demo saw the Bash result. Response preview: one

──────────────────────────────────────────────────────────────────────────────────────────────────────

• Ran them in parallel. Little wave report:

  - echo 'one' completed and returned one.
  - echo '[block-pre-tool-use]' was blocked before execution by the PreToolUse hook.
  - echo '[block-post-tool-use]' ran, but its result was blocked afterward by the PostToolUse hook.

  The hook messages were:

  - PreToolUse demo blocked the command. Remove [block-pre-tool-use] to continue.
  - PostToolUse demo blocked the result after execution. Remove [block-post-tool-use] to continue.


› for the blocked messages (correctly blocked in this test) did the tool output land back into
  context?


• Yeah, from this run:

  - PreToolUse block: the command itself did not execute, so no command output landed in context. Only
    the block message did.
  - PostToolUse block: the command did execute, but the actual stdout did not come back into context.
    Only the post-tool block message did.

  So the blocked notifications landed in context, but the blocked command payloads themselves did not.
  Nice clean guardrail, aloha.
```
2026-03-25 19:18:03 -07:00
Ahmed IbrahimandCodex 9dbe098349 Extract codex-core-skills crate (#15749)
## Summary
- move skill loading and management into codex-core-skills
- leave codex-core with the thin integration layer and shared wiring

## Testing
- CI

---------

Co-authored-by: Codex <noreply@openai.com>
2026-03-25 12:57:42 -07:00
Matthew Zeng 91337399fe [apps][tool_suggest] Remove tool_suggest's dependency on tool search. (#14856)
- [x] Remove tool_suggest's dependency on tool search.
2026-03-25 12:26:02 -07:00
jif-oaiandCodex 14c35a16a8 chore: remove read_file handler (#15773)
Co-authored-by: Codex <noreply@openai.com>
2026-03-25 16:27:32 +00:00
pakrym-oai 504aeb0e09 Use AbsolutePathBuf for cwd state (#15710)
Migrate `cwd` and related session/config state to `AbsolutePathBuf` so
downstream consumers consistently see absolute working directories.

Add test-only `.abs()` helpers for `Path`, `PathBuf`, and `TempDir`, and
update branch-local tests to use them instead of
`AbsolutePathBuf::try_from(...)`.

For the remaining TUI/app-server snapshot coverage that renders absolute
cwd values, keep the snapshots unchanged and skip the Windows-only cases
where the platform-specific absolute path layout differs.
2026-03-25 16:02:22 +00:00
jif-oaiandCodex 178c3b15b4 chore: remove grep_files handler (#15775)
# External (non-OpenAI) Pull Request Requirements

Before opening this Pull Request, please read the dedicated
"Contributing" markdown file or your PR may be closed:
https://github.com/openai/codex/blob/main/docs/contributing.md

If your PR conforms to our contribution guidelines, replace this text
with a detailed and high quality description of your changes.

Include a link to a bug report or enhancement request.

---------

Co-authored-by: Codex <noreply@openai.com>
2026-03-25 16:01:45 +00:00
jif-oai 047ea642d2 chore: tty metric (#15766) 2026-03-25 13:34:43 +00:00
pakrym-oai 0b619afc87 Drop sandbox_permissions from sandbox exec requests (#15665)
## Summary
- drop `sandbox_permissions` from the sandboxing `ExecOptions` and
`ExecRequest` adapter types
- remove the now-unused plumbing from shell, unified exec, JS REPL, and
apply-patch runtime call sites
- default reconstructed `ExecParams` to `SandboxPermissions::UseDefault`
where the lower-level API still requires the field

## Testing
- `just fmt`
- `just argument-comment-lint`
- `cargo test -p codex-core` (still running locally; first failures
observed in `suite::cli_stream::responses_mode_stream_cli`,
`suite::cli_stream::responses_mode_stream_cli_supports_openai_base_url_config_override`,
and
`suite::cli_stream::responses_mode_stream_cli_supports_openai_base_url_env_fallback`)
2026-03-24 15:42:45 -07:00
xl-openai 621862a7d1 feat: include marketplace loading error in plugin/list (#15438)
Include error.
2026-03-24 11:47:23 -07:00
jif-oai 773fbf56a4 feat: communication pattern v2 (#15647)
See internal communication
2026-03-24 18:45:49 +00:00
jif-oai 38c088ba8d feat: list agents for sub-agent v2 (#15621)
Add a `list_agents` for multi-agent v2, optionally path based

This return the task and status of each agent in the matched path
2026-03-24 11:24:08 +00:00
pakrym-oai 9deb8ce3fc Move sandbox policy transforms into codex-sandboxing (#15599)
## Summary
- move the pure sandbox policy transform helpers from `codex-core` into
`codex-sandboxing`
- move the corresponding unit tests with the extracted implementation
- update `core` and `app-server` callers to import the moved APIs
directly, without re-exports or proxy methods

## Testing
- cargo test -p codex-sandboxing
- cargo test -p codex-core sandboxing
- cargo test -p codex-app-server --lib
- just fix -p codex-sandboxing
- just fix -p codex-core
- just fix -p codex-app-server
- just fmt
- just argument-comment-lint
2026-03-23 22:22:44 -07:00
dhruvgupta-oai c2410060ea [codex-cli][app-server] Update self-serve business usage limit copy in error returned (#15478)
## Summary
- update the self-serve business usage-based limit message to direct
users to their admin for additional credits
- add a focused unit test for the self_serve_business_usage_based plan
branch

Added also: 

If you are at a rate limit but you still have credits, codex cli would
tell you to switch the model. We shouldnt do this if you have credits so
fixed this.

## Test
- launched the source-built CLI and verified the updated message is
shown for the self-serve business usage-based plan

![Test
screenshot](https://raw.githubusercontent.com/openai/codex/5cc3c013ef17ac5c66dfd9395c0d3c4837602231/docs/images/self-serve-business-usage-limit.png)
2026-03-24 04:41:38 +00:00
jif-oai 527244910f feat: custom watcher for multi-agent v2 (#15576)
The new wait tool just returns `Wait timed out.` or `Wait completed.`.
The actual content is done through the notification watcher
2026-03-23 23:27:55 +00:00
jif-oai 4605c65308 feat: custom watcher for multi-agent v2 (#15570)
Custom watcher that sends an InterAgentCommunication on end of turn
2026-03-23 22:56:17 +00:00
jif-oai 191fd9fd16 feat: use serde to differenciate inter agent communication (#15560)
Use `serde` to encode the inter agent communication to an assistant
message and use the decode to see if this is such a message

Note: this assume serde on small pattern is fast enough
2026-03-23 22:09:55 +00:00
jif-oai 18f1a08bc9 feat: new op type for sub-agents communication (#15556)
Add `InterAgentCommunication` for v2 agent communication
2026-03-23 21:09:00 +00:00
jif-oai 450dc289c3 chore: split sub-agent v2 implementation (#15540)
Just to make things cleaner
2026-03-23 19:41:53 +00:00
jif-oai 37ac0c093c feat: structured multi-agent output (#15515)
Send input now sends messages as assistant message and with this format:

```
author: /root/worker_a
recipient: /root/worker_a/tester
other_recipients: []
Content: bla bla bla. Actual content. Only text for now
```
2026-03-23 18:53:54 +00:00
jif-oai 79ad7b247b feat: change multi-agent to use path-like system instead of uuids (#15313)
This PR add an URI-based system to reference agents within a tree. This
comes from a sync between research and engineering.

The main agent (the one manually spawned by a user) is always called
`/root`. Any sub-agent spawned by it will be `/root/agent_1` for example
where `agent_1` is chosen by the model.

Any agent can contact any agents using the path.

Paths can be used either in absolute or relative to the calling agents

Resume is not supported for now on this new path
2026-03-20 18:23:48 +00:00
2e22885e79 Split features into codex-features crate (#15253)
- Split the feature system into a new `codex-features` crate.
- Cut `codex-core` and workspace consumers over to the new config and
warning APIs.

Co-authored-by: Ahmed Ibrahim <219906144+aibrahim-oai@users.noreply.github.com>
Co-authored-by: Codex <noreply@openai.com>
2026-03-19 20:12:07 -07:00
Michael Bolin a3e59e9e85 core: add a full-buffer exec capture policy (#15254) 2026-03-20 02:38:12 +00:00
pakrym-oai 403b397e4e Refactor ExecServer filesystem split between local and remote (#15232)
For each feature we have:
1. Trait exposed on environment
2. **Local Implementation** of the trait
3. Remote implementation that uses the client to proxy via network
4. Handler implementation that handles PRC requests and calls into
**Local Implementation**
2026-03-19 17:08:04 -07:00
pakrym-oai dee03da508 Move environment abstraction into exec server (#15125)
The idea is that codex-exec exposes an Environment struct with services
on it. Each of those is a trait.

Depending on construction parameters passed to Environment they are
either backed by local or remote server but core doesn't see these
differences.
2026-03-19 08:31:14 -07:00
jif-oai 32d2df5c1e fix: case where agent is already closed (#15163) 2026-03-19 12:12:50 +00:00
jif-oai 70cdb17703 feat: add graph representation of agent network (#15056)
Add a representation of the agent graph. This is now used for:
* Cascade close agents (when I close a parent, it close the kids)
* Cascade resume (oposite)

Later, this will also be used for post-compaction stuffing of the
context

Direct fix for: https://github.com/openai/codex/issues/14458
2026-03-19 10:21:25 +00:00
pakrym-oai 56d0c6bf67 Add apply_patch code mode result (#15100)
It's empty !
2026-03-18 16:11:10 -07:00
pakrym-oai 3590e181fa Add update_plan code mode result (#15103)
It's empty!
2026-03-18 16:10:51 -07:00
pakrym-oai 5cada46ddf Return image URL from view_image tool (#15072)
Cleanup image semantics in code mode.

`view_image` now returns `{image_url:string, details?: string}` 

`image()` now allows both string parameter and `{image_url:string,
details?: string}`
2026-03-18 13:58:20 -07:00
jif-oai 0f9484dc8a feat: adapt artifacts to new packaging and 2.5.6 (#14947) 2026-03-18 09:17:44 +00:00
pakrym-oai 83a60fdb94 Add FS abstraction and use in view_image (#14960)
Adds an environment crate and environment + file system abstraction.

Environment is a combination of attributes and services specific to
environment the agent is connected to:
File system, process management, OS, default shell.

The goal is to move most of agent logic that assumes environment to work
through the environment abstraction.
2026-03-17 17:36:23 -07:00
Matthew Zeng 683c37ce75 [plugins] Support plugin installation elicitation. (#14896)
It now supports:

- Connectors that are from installed and enabled plugins that are not
installed yet
- Plugins that are on the allowlist that are not installed yet.
2026-03-17 13:19:28 -07:00
jif-oai e8add54e5d feat: show effective model in spawn agent event (#14944)
Show effective model after the full config layering for the sub agent
2026-03-17 16:58:58 +00:00
daveaitel-openai ef36d39199 Fix agent jobs finalization race and reduce status polling churn (#14843)
## Summary
- make `report_agent_job_result` atomically transition an item from
running to completed while storing `result_json`
- remove brittle finalization grace-sleep logic and make finished-item
cleanup idempotent
- replace blind fixed-interval waiting with status-subscription-based
waiting for active worker threads
- add state runtime tests for atomic completion and late-report
rejection

## Why
This addresses the race and polling concerns in #13948 by removing
timing-based correctness assumptions and reducing unnecessary status
polling churn.

## Validation
- `cd codex-rs && just fmt`
- `cd codex-rs && cargo test -p codex-state`
- `cd codex-rs && cargo test -p codex-core --test all suite::agent_jobs`
- `cd codex-rs && cargo test`
- fails in an unrelated app-server tracing test:
`message_processor::tracing_tests::thread_start_jsonrpc_span_exports_server_span_and_parents_children`
timed out waiting for response

## Notes
- This PR supersedes #14129 with the same agent-jobs fix on a clean
branch from `main`.
- The earlier PR branch was stacked on unrelated history, which made the
review diff include unrelated commits.

Fixes #13948
2026-03-17 10:40:14 -04:00
jif-oai 4ed19b0766 feat: rename to get more explicit close agent (#14935)
https://github.com/openai/codex/issues/14907
2026-03-17 14:37:20 +00:00
jif-oai 31648563c8 feat: centralize package manager version (#14920) 2026-03-17 12:03:07 +00:00
Michael Bolin b77fe8fefe Apply argument comment lint across codex-rs (#14652)
## Why

Once the repo-local lint exists, `codex-rs` needs to follow the
checked-in convention and CI needs to keep it from drifting. This commit
applies the fallback `/*param*/` style consistently across existing
positional literal call sites without changing those APIs.

The longer-term preference is still to avoid APIs that require comments
by choosing clearer parameter types and call shapes. This PR is
intentionally the mechanical follow-through for the places where the
existing signatures stay in place.

After rebasing onto newer `main`, the rollout also had to cover newly
introduced `tui_app_server` call sites. That made it clear the first cut
of the CI job was too expensive for the common path: it was spending
almost as much time installing `cargo-dylint` and re-testing the lint
crate as a representative test job spends running product tests. The CI
update keeps the full workspace enforcement but trims that extra
overhead from ordinary `codex-rs` PRs.

## What changed

- keep a dedicated `argument_comment_lint` job in `rust-ci`
- mechanically annotate remaining opaque positional literals across
`codex-rs` with exact `/*param*/` comments, including the rebased
`tui_app_server` call sites that now fall under the lint
- keep the checked-in style aligned with the lint policy by using
`/*param*/` and leaving string and char literals uncommented
- cache `cargo-dylint`, `dylint-link`, and the relevant Cargo
registry/git metadata in the lint job
- split changed-path detection so the lint crate's own `cargo test` step
runs only when `tools/argument-comment-lint/*` or `rust-ci.yml` changes
- continue to run the repo wrapper over the `codex-rs` workspace, so
product-code enforcement is unchanged

Most of the code changes in this commit are intentionally mechanical
comment rewrites or insertions driven by the lint itself.

## Verification

- `./tools/argument-comment-lint/run.sh --workspace`
- `cargo test -p codex-tui-app-server -p codex-tui`
- parsed `.github/workflows/rust-ci.yml` locally with PyYAML

---

* -> #14652
* #14651
2026-03-16 16:48:15 -07:00
viyatb-oai 7f571396c8 fix: sync split sandbox policies for spawned subagents (#14650)
## Summary
- reapply the live split filesystem and network sandbox policies when
building spawned subagent configs
- keep spawned child sessions aligned with the parent turn after
role-layer config reloads
- add regression coverage for both config construction and spawned
child-turn inheritance
2026-03-14 03:03:49 +00:00
Eric Traut 4b9d5c8c1b Add openai_base_url config override for built-in provider (#12031)
We regularly get bug reports from users who mistakenly have the
`OPENAI_BASE_URL` environment variable set. This PR deprecates this
environment variable in favor of a top-level config key
`openai_base_url` that is used for the same purpose. By making it a
config key, it will be more visible to users. It will also participate
in all of the infrastructure we've added for layered and managed
configs.

Summary
- introduce the `openai_base_url` top-level config key, update
schema/tests, and route the built-in openai provider through it while
- fall back to deprecated `OPENAI_BASE_URL` env var but warn user of
deprecation when no `openai_base_url` config key is present
- update CLI, SDK, and TUI code to prefer the new config path (with a
deprecated env-var fallback) and document the SDK behavior change
2026-03-13 20:12:25 -06:00
Michael Bolin b859a98e0f refactor: make unified-exec zsh-fork state explicit (#14633)
## Why

The unified-exec path was carrying zsh-fork state in a partially
flattened way.

First, the decision about whether zsh-fork was active came from feature
selection in `ToolsConfig`, while the real prerequisites lived in
session state. That left the handler and runtime defending against
partially configured cases later.

Second, once zsh-fork was active, its two runtime-only paths were
threaded through the runtime as separate arguments even though they form
one coherent piece of configuration.

This change keeps unified-exec on a single session-derived source of
truth and bundles the zsh-fork-specific paths into a named config type
so the runtime can pass them around as one unit.

In particular, this PR introduces this enum so the `ZshFork` variant can
carry the appropriate state with it:

```rust
#[derive(Debug, Clone, Eq, PartialEq)]
pub enum UnifiedExecShellMode {
    Direct,
    ZshFork(ZshForkConfig),
}

#[derive(Debug, Clone, Eq, PartialEq)]
pub struct ZshForkConfig {
    pub(crate) shell_zsh_path: AbsolutePathBuf,
    pub(crate) main_execve_wrapper_exe: AbsolutePathBuf,
}
```

This cleanup was done in preparation for
https://github.com/openai/codex/pull/13432.

## What Changed

- Replaced the feature-only `UnifiedExecBackendConfig` split with
`UnifiedExecShellMode` in `codex-rs/core/src/tools/spec.rs`.
- Derived the unified-exec mode from session-backed inputs when building
turn `ToolsConfig`, and preserved that mode across model switches and
review turns.
- Introduced `ZshForkConfig`, which stores the resolved zsh-fork
`AbsolutePathBuf` values for the configured `zsh` binary and `execve`
wrapper.
- Threaded `ZshForkConfig` through unified-exec command construction and
the zsh-fork preparation path so zsh-fork-specific runtime code consumes
a single config object instead of separate path arguments.
- Added focused tests for constructing zsh-fork mode only when session
prerequisites are available, and updated the zsh-fork expectations to be
target-platform aware.

## Testing

- `cargo test -p codex-core zsh_fork --lib`


---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/14633).
* #13432
* __->__ #14633
2026-03-13 17:20:01 -07:00