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codex/codex-rs/core
T
Owen Lin 0b9e42f6f7 fix(guardian): don't throw away transcript when over budget (#16956)
## Description

This PR changes guardian transcript compaction so oversized
conversations no longer collapse into a nearly empty placeholder.

Before this change, if the retained user history alone exceeded the
message budget, guardian would replace the entire transcript with
`<transcript omitted to preserve budget for planned action>`!

That meant approvals, especially network approvals, could lose the
recent tool call and tool result that explained what guardian was
actually reviewing. Now we keep a compact but usable transcript instead
of dropping it all.

### Before
```
The following is the Codex agent history whose request action you are assessing...
>>> TRANSCRIPT START
<transcript omitted to preserve budget for planned action>
>>> TRANSCRIPT END

Conversation transcript omitted due to size.

The Codex agent has requested the following action:
>>> APPROVAL REQUEST START
Retry reason:
Sandbox blocked outbound network access.

Assess the exact planned action below. Use read-only tool checks when local state matters.
Planned action JSON:
{
  "tool": "network_access",
  "target": "https://example.com:443",
  "host": "example.com",
  "protocol": "https",
  "port": 443
}
>>> APPROVAL REQUEST END
```

### After
```
The following is the Codex agent history whose request action you are assessing...
>>> TRANSCRIPT START
[1] user: Please investigate why uploads to example.com are failing and retry if needed.
[8] user: If the request looks correct, go ahead and try again with network access.
[9] tool shell call: {"command":["curl","-X","POST","https://example.com/upload"],"cwd":"/repo"}
[10] tool shell result: sandbox blocked outbound network access
>>> TRANSCRIPT END

Some conversation entries were omitted.

The Codex agent has requested the following action:
>>> APPROVAL REQUEST START
Retry reason:
Sandbox blocked outbound network access.

Assess the exact planned action below. Use read-only tool checks when local state matters.
Planned action JSON:
{
  "tool": "network_access",
  "target": "https://example.com:443",
  "host": "example.com",
  "protocol": "https",
  "port": 443
}
>>> APPROVAL REQUEST END
```
0b9e42f6f7 ยท 2026-04-07 10:19:16 -07:00
History
..

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.