Files
codex/codex-rs/core
jgershen-oai 8f705b0702 [codex] Defer steering until after sampling the model post-compaction (#17163)
## Summary
- keep pending steered input buffered until the active user prompt has
received a model response
- keep steering pending across auto-compact when there is real
model/tool continuation to resume
- allow queued steering to follow compaction immediately when the prior
model response was already final
- keep pending-input follow-up owned by `run_turn` instead of folding it
into `SamplingRequestResult`
- add regression coverage for mid-turn compaction, final-response
compaction, and compaction triggered before the next request after tool
output

## Root Cause
Steered input was drained at the top of every `run_turn` loop. After
auto-compaction, the loop continued and immediately appended any pending
steer after the compact summary, making a queued prompt look like the
newest task instead of letting the model first resume interrupted
model/tool work.

## Implementation Notes
This patch keeps the follow-up signals separated:

- `SamplingRequestResult.needs_follow_up` means model/tool continuation
is needed
- `sess.has_pending_input().await` means queued user steering exists
- `run_turn` computes the combined loop condition from those two signals

In `run_turn`:

```rust
let has_pending_input = sess.has_pending_input().await;
let needs_follow_up = model_needs_follow_up || has_pending_input;
```

After auto-compact we choose whether the next request may drain
steering:

```rust
can_drain_pending_input = !model_needs_follow_up;
```

That means:

- model/tool continuation + pending steer: compact -> resume once
without draining steer
- completed model answer + pending steer: compact -> drain/send the
steer immediately
- fresh user prompt: do not drain steering before the model has answered
the prompt once

The drain is still only `sess.get_pending_input().await`; when
`can_drain_pending_input` is false, core uses an empty local vec and
leaves the steer pending in session state.

## Validation
- PASS `cargo test -p codex-core --test all steered_user_input --
--nocapture`
- PASS `just fmt`
- PASS `git diff --check`
- NOT PASSING HERE `just fix -p codex-core` currently stops before
linting this change on an unrelated mainline test-build error:
`core/src/tools/spec_tests.rs` initializes `ToolsConfigParams` without
`image_generation_tool_auth_allowed`; this PR does not touch that file.
2026-04-09 02:08:41 -07:00
..

codex-core

This crate implements the business logic for Codex. It is designed to be used by the various Codex UIs written in Rust.

Dependencies

Note that codex-core makes some assumptions about certain helper utilities being available in the environment. Currently, this support matrix is:

macOS

Expects /usr/bin/sandbox-exec to be present.

When using the workspace-write sandbox policy, the Seatbelt profile allows writes under the configured writable roots while keeping .git (directory or pointer file), the resolved gitdir: target, and .codex read-only.

Network access and filesystem read/write roots are controlled by SandboxPolicy. Seatbelt consumes the resolved policy and enforces it.

Seatbelt also keeps the legacy default preferences read access (user-preference-read) needed for cfprefs-backed macOS behavior.

Linux

Expects the binary containing codex-core to run the equivalent of codex sandbox linux (legacy alias: codex debug landlock) when arg0 is codex-linux-sandbox. See the codex-arg0 crate for details.

Legacy SandboxPolicy / sandbox_mode configs are still supported on Linux. They can continue to use the legacy Landlock path when the split filesystem policy is sandbox-equivalent to the legacy model after cwd resolution. Split filesystem policies that need direct FileSystemSandboxPolicy enforcement, such as read-only or denied carveouts under a broader writable root, automatically route through bubblewrap. The legacy Landlock path is used only when the split filesystem policy round-trips through the legacy SandboxPolicy model without changing semantics. That includes overlapping cases like /repo = write, /repo/a = none, /repo/a/b = write, where the more specific writable child must reopen under a denied parent.

The Linux sandbox helper prefers the first bwrap found on PATH outside the current working directory whenever it is available. If bwrap is present but too old to support --argv0, the helper keeps using system bubblewrap and switches to a no---argv0 compatibility path for the inner re-exec. If bwrap is missing, it falls back to the vendored bubblewrap path compiled into the binary and Codex surfaces a startup warning through its normal notification path instead of printing directly from the sandbox helper. Codex also surfaces a startup warning when bubblewrap cannot create user namespaces.

Windows

Legacy SandboxPolicy / sandbox_mode configs are still supported on Windows.

The elevated setup/runner backend supports legacy ReadOnlyAccess::Restricted for read-only and workspace-write policies. Restricted read access honors explicit readable roots plus the command cwd, and keeps writable roots readable when workspace-write is used.

When include_platform_defaults = true, the elevated Windows backend adds backend-managed system read roots required for basic execution, such as C:\Windows, C:\Program Files, C:\Program Files (x86), and C:\ProgramData. When it is false, those extra system roots are omitted.

The unelevated restricted-token backend still supports the legacy full-read Windows model for legacy ReadOnly and WorkspaceWrite behavior. It also supports a narrow split-filesystem subset: full-read split policies whose writable roots still match the legacy WorkspaceWrite root set, but add extra read-only carveouts under those writable roots.

New [permissions] / split filesystem policies remain supported on Windows only when they round-trip through the legacy SandboxPolicy model without changing semantics. Policies that would require direct read restriction, explicit unreadable carveouts, reopened writable descendants under read-only carveouts, different writable root sets, or split carveout support in the elevated setup/runner backend still fail closed instead of running with weaker enforcement.

All Platforms

Expects the binary containing codex-core to simulate the virtual apply_patch CLI when arg1 is --codex-run-as-apply-patch. See the codex-arg0 crate for details.