## What changed
- Replace individual JSON payload files with numbered Zstandard shards in trace schema v3. Add `PayloadReader` to resolve payload references, cache decoded shards, and validate payloads during replay.
- Capture exact outgoing HTTP bodies and WebSocket messages alongside prepared prompts. Preserve full formatted context for continuations from unrecorded WebSocket warmups while retaining the actual incremental request.
- Flush payload records before publishing references and seal the final shard before recording completion. Replace `recording_complete` with `recording_status` to distinguish unclosed recordings, closed recordings with partial payloads, and complete recordings.
Reduce trace bundles with the binary that recorded them.
## Testing
Add coverage for shard rotation, oversized records, live reads, cache eviction, and malformed or corrupt payloads. Extend HTTP and WebSocket integration assertions to verify captured requests and prepared prompts, including warmup continuations.
GitOrigin-RevId: 40ce3c11383f48e08f52e7120b706c61a449df9c
## Why
Raw trace events and payloads are implementation details of the recording executable. Matching release or schema versions do not establish compatibility with another binary.
## What changed
- Document that bundles must be reduced by the exact executable that recorded them, with `state.json` as the consumer API and `manifest.json` for discovery and identity.
- Require explicit thread IDs on code-cell runtime events and use structured agent-message metadata instead of parsing legacy assistant-message JSON.
- Include expected schema versions and guidance to use the recording executable in schema mismatch errors.
- Update agent-delivery test fixtures to use structured `agent_message` inputs and check manifest schema rejection directly.
GitOrigin-RevId: 67206fa554f1ba9c1bf9bfdad54840b5d86c5a77
## Why
Enabled rollout tracing could silently fail to initialize, and a terminal task status did not establish whether all recording had finished. Trace consumers need to distinguish a complete recording from a partial bundle, including when a task is interrupted.
## What changed
- Fail thread startup or resume if an enabled recorder cannot initialize, while cleaning up session resources.
- Stop recording after the first write or serialization failure and preserve that failure across shared producers.
- Append a closing record when the last writer handle is released without recording errors. Expose `recording_complete` in `state.json` independently of task success, and mark submission-channel closure as an aborted rollout.
- Reject replay logs with missing or reordered events, mismatched rollout IDs, events after completion, or missing or invalid JSON payloads. Valid prefixes remain replayable with `recording_complete` set to `false`.
## Testing
Add coverage for startup failure and recovery, shared-writer failures, finalization after child handles close, incomplete logs, and missing or malformed payloads. Extend session and CLI tests to check recording completion after shutdown, interruption, stream failure, and submission-channel closure.
GitOrigin-RevId: 30d62fa95912fb0442ad1199776d110884066c30
## Summary
Renames the MultiAgentV2 turn-triggering tool from `assign_task` to
`followup_task` so the exposed tool name better describes sending an
additional task to an existing agent.
This updates the tool spec, handler/module names, registry wiring,
default multi-agent v2 usage hints, and tests. Rollout trace
classification keeps accepting legacy `assign_task` events so older
traces still reduce correctly, while docs show the new tool name.
## Test plan
- `just test -p codex-core followup_task`
- `just test -p codex-core -E
'test(multi_agent_feature_selects_one_agent_tool_family) |
test(multi_agent_v2_can_use_configured_tool_namespace) |
test(code_mode_only_can_expose_namespaced_multi_agent_v2_as_normal_tools)'`
- `just test -p codex-rollout-trace`
- `just fix -p codex-core`
- `just fix -p codex-rollout-trace`
Notes: `just fmt` ran `cargo fmt` but failed in the Python ruff phase
because the local environment could not resolve `hatchling>=1.27.0` from
the configured internal registry. A full `just test -p codex-core` also
hit unrelated environment-sensitive integration failures involving
missing spawned test binaries/sandbox behavior; the changed multi-agent
spec/handler tests passed in the filtered runs above.
## Summary
- rename the multi-agent v2 follow-up task tool surface to assign_task
- update core tests and spec-plan expectations
- keep rollout-trace classification backward-compatible with legacy
followup_task
## Tests
- just fmt
- just test -p codex-core
multi_agents_spec::tests::assign_task_tool_requires_message_and_has_no_output_schema
- just test -p codex-rollout-trace
- just fix -p codex-core
- just fix -p codex-rollout-trace
Note: a broad just test -p codex-core run was attempted locally, but
this sandbox produced unrelated environment failures around
sandbox-exec, missing test_stdio_server, and realtime timeouts.
## 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
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.
cassirer-openai