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. ```
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 supports macOS permission-profile extensions layered on top of
SandboxPolicy:
- no extension profile provided:
keeps legacy default preferences read access (
user-preference-read). - extension profile provided with no
macos_preferencesgrant: does not add preferences access clauses. macos_preferences = "readonly": enables cfprefs read clauses anduser-preference-read.macos_preferences = "readwrite": includes readonly clauses plususer-preference-writeand cfprefs shm write clauses.macos_automation = true: enables broad Apple Events send permissions.macos_automation = ["com.apple.Notes", ...]: enables Apple Events send only to listed bundle IDs.macos_launch_services = true: enables LaunchServices lookups and open/launch operations.macos_accessibility = true: enablescom.apple.axservermach lookup.macos_calendar = true: enablescom.apple.CalendarAgentmach lookup.macos_contacts = "read_only": enables Address Book read access and Contacts read services.macos_contacts = "read_write": includes the readonly Contacts clauses plus Address Book writes and keychain/temp helpers required for writes.
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 /usr/bin/bwrap whenever it is available and
supports the required argv-rewrite flags, and falls back to the vendored
bubblewrap path compiled into the binary otherwise. When /usr/bin/bwrap is
missing or too old to support the required flags, Codex also surfaces a startup
warning through its normal notification path instead of printing directly from
the sandbox helper.
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.