## Why
`PermissionProfile` is becoming the canonical permissions abstraction,
but the old shape only carried optional filesystem and network fields.
It could describe allowed access, but not who is responsible for
enforcing it. That made `DangerFullAccess` and `ExternalSandbox` lossy
when profiles were exported, cached, or round-tripped through app-server
APIs.
The important model change is that active permissions are now a disjoint
union over the enforcement mode. Conceptually:
```rust
pub enum PermissionProfile {
Managed {
file_system: FileSystemSandboxPolicy,
network: NetworkSandboxPolicy,
},
Disabled,
External {
network: NetworkSandboxPolicy,
},
}
```
This distinction matters because `Disabled` means Codex should apply no
outer sandbox at all, while `External` means filesystem isolation is
owned by an outside caller. Those are not equivalent to a broad managed
sandbox. For example, macOS cannot nest Seatbelt inside Seatbelt, so an
inner sandbox may require the outer Codex layer to use no sandbox rather
than a permissive one.
## How Existing Modeling Maps
Legacy `SandboxPolicy` remains a boundary projection, but it now maps
into the higher-fidelity profile model:
- `ReadOnly` and `WorkspaceWrite` map to `PermissionProfile::Managed`
with restricted filesystem entries plus the corresponding network
policy.
- `DangerFullAccess` maps to `PermissionProfile::Disabled`, preserving
the “no outer sandbox” intent instead of treating it as a lax managed
sandbox.
- `ExternalSandbox { network_access }` maps to
`PermissionProfile::External { network }`, preserving external
filesystem enforcement while still carrying the active network policy.
- Split runtime policies that legacy `SandboxPolicy` cannot faithfully
express, such as managed unrestricted filesystem plus restricted
network, stay `Managed` instead of being collapsed into
`ExternalSandbox`.
- Per-command/session/turn grants remain partial overlays via
`AdditionalPermissionProfile`; full `PermissionProfile` is reserved for
complete active runtime permissions.
## What Changed
- Change active `PermissionProfile` into a tagged union: `managed`,
`disabled`, and `external`.
- Keep partial permission grants separate with
`AdditionalPermissionProfile` for command/session/turn overlays.
- Represent managed filesystem permissions as either `restricted`
entries or `unrestricted`; `glob_scan_max_depth` is non-zero when
present.
- Preserve old rollout compatibility by accepting the pre-tagged `{
network, file_system }` profile shape during deserialization.
- Preserve fidelity for important edge cases: `DangerFullAccess`
round-trips as `disabled`, `ExternalSandbox` round-trips as `external`,
and managed unrestricted filesystem + restricted network stays managed
instead of being mistaken for external enforcement.
- Preserve configured deny-read entries and bounded glob scan depth when
full profiles are projected back into runtime policies, including
unrestricted replacements that now become `:root = write` plus deny
entries.
- Regenerate the experimental app-server v2 JSON/TypeScript schema and
update the `command/exec` README example for the tagged
`permissionProfile` shape.
## Compatibility
Legacy `SandboxPolicy` remains available at config/API boundaries as the
compatibility projection. Existing rollout lines with the old
`PermissionProfile` shape continue to load. The app-server
`permissionProfile` field is experimental, so its v2 wire shape is
intentionally updated to match the higher-fidelity model.
## Verification
- `just write-app-server-schema`
- `cargo check --tests`
- `cargo test -p codex-protocol permission_profile`
- `cargo test -p codex-protocol
preserving_deny_entries_keeps_unrestricted_policy_enforceable`
- `cargo test -p codex-app-server-protocol
permission_profile_file_system_permissions`
- `cargo test -p codex-app-server-protocol serialize_client_response`
- `cargo test -p codex-core
session_configured_reports_permission_profile_for_external_sandbox`
- `just fix`
- `just fix -p codex-protocol`
- `just fix -p codex-app-server-protocol`
- `just fix -p codex-core`
- `just fix -p codex-app-server`
## Summary
Adds the debug CLI entry point for reducing recorded rollout traces.
This gives developers a direct way to inspect whether the emitted trace
stream reduces into the expected conversation/runtime model.
## Stack
This is PR 5/5 in the rollout trace stack.
- [#18876](https://github.com/openai/codex/pull/18876): Add rollout
trace crate
- [#18877](https://github.com/openai/codex/pull/18877): Record core
session rollout traces
- [#18878](https://github.com/openai/codex/pull/18878): Trace tool and
code-mode boundaries
- [#18879](https://github.com/openai/codex/pull/18879): Trace sessions
and multi-agent edges
- [#18880](https://github.com/openai/codex/pull/18880): Add debug trace
reduction command
## Review Notes
This PR is intentionally last: it depends on the trace crate, core
recorder, runtime/tool events, and session/agent edge data all existing.
The command should remain a debug/developer tool and avoid adding new
runtime behavior.
The useful review question is whether the CLI exposes the reducer in the
smallest practical way for local inspection without turning the debug
command into a supported user-facing workflow.
## Summary
Extends rollout tracing across tool dispatch and code-mode runtime
boundaries. This records canonical tool-call lifecycle events and links
code-mode execution/wait operations back to the model-visible calls that
caused them.
## Stack
This is PR 3/5 in the rollout trace stack.
- [#18876](https://github.com/openai/codex/pull/18876): Add rollout
trace crate
- [#18877](https://github.com/openai/codex/pull/18877): Record core
session rollout traces
- [#18878](https://github.com/openai/codex/pull/18878): Trace tool and
code-mode boundaries
- [#18879](https://github.com/openai/codex/pull/18879): Trace sessions
and multi-agent edges
- [#18880](https://github.com/openai/codex/pull/18880): Add debug trace
reduction command
## Review Notes
This PR is about attribution. Reviewers should focus on whether direct
tool calls, code-mode-originated tool calls, waits, outputs, and
cancellation boundaries are recorded with enough source information for
deterministic reduction without coupling the reducer to live runtime
internals.
The stack remains valid after this layer: tool and code-mode traces
reduce through the existing crate model, while the broader session and
multi-agent relationships are added in the next PR.
## Summary
Wires rollout trace recording into `codex-core` session and turn
execution. This records the core model request/response, compaction, and
session lifecycle boundaries needed for replay without yet tracing every
nested runtime/tool boundary.
## Stack
This is PR 2/5 in the rollout trace stack.
- [#18876](https://github.com/openai/codex/pull/18876): Add rollout
trace crate
- [#18877](https://github.com/openai/codex/pull/18877): Record core
session rollout traces
- [#18878](https://github.com/openai/codex/pull/18878): Trace tool and
code-mode boundaries
- [#18879](https://github.com/openai/codex/pull/18879): Trace sessions
and multi-agent edges
- [#18880](https://github.com/openai/codex/pull/18880): Add debug trace
reduction command
## Review Notes
This layer is the first live integration point. The important review
question is whether trace recording is isolated from normal session
behavior: trace failures should not become user-visible execution
failures, and recording should preserve the existing turn/session
lifecycle semantics.
The PR depends on the reducer/data model from the first stack entry and
only introduces the core recorder surface that later PRs use for richer
runtime and relationship events.
## Summary
Adds the standalone `codex-rollout-trace` crate, which defines the raw
trace event format, replay/reduction model, writer, and reducer logic
for reconstructing model-visible conversation/runtime state from
recorded rollout data.
The crate-level design is documented in
[`codex-rs/rollout-trace/README.md`](https://github.com/openai/codex/blob/codex/rollout-trace-crate/codex-rs/rollout-trace/README.md).
## Stack
This is PR 1/5 in the rollout trace stack.
- [#18876](https://github.com/openai/codex/pull/18876): Add rollout
trace crate
- [#18877](https://github.com/openai/codex/pull/18877): Record core
session rollout traces
- [#18878](https://github.com/openai/codex/pull/18878): Trace tool and
code-mode boundaries
- [#18879](https://github.com/openai/codex/pull/18879): Trace sessions
and multi-agent edges
- [#18880](https://github.com/openai/codex/pull/18880): Add debug trace
reduction command
## Review Notes
This PR intentionally does not wire tracing into live Codex execution.
It establishes the data model and reducer contract first, with
crate-local tests covering conversation reconstruction, compaction
boundaries, tool/session edges, and code-cell lifecycle reduction. Later
PRs emit into this model.
The README is the best entry point for reviewing the intended trace
format and reduction semantics before diving into the reducer modules.
Michael Bolin ·
cassirer-openai ·