## Why
The rendered `<token_budget>` fragment identifies the thread and current
context window, but it does not expose enough lineage to identify the
first window in the thread or the immediately preceding window. Those
IDs also need to remain stable across compaction, resume, and rollback.
## What changed
- Track first, previous, and current UUIDv7 context-window IDs in
auto-compaction state.
- Render `thread_id`, `first_window_id`, `previous_window_id`, and the
current window ID in the full `<token_budget>` fragment.
- Persist the first and previous window IDs in compacted rollout
checkpoints and restore them during rollout reconstruction.
- Preserve compatibility with older compacted records that do not
contain the new optional fields.
- Update focused state, rendering, reconstruction, rollback, and
serialization coverage.
## Validation
- `just test -p codex-core token_budget`
- `just test -p codex-protocol compacted_item::tests`
- `just test -p codex-core tracks_prefill_and_window_boundaries`
- `just test -p codex-core
reconstruct_history_uses_replacement_history_verbatim`
- `just test -p codex-core
thread_rollback_restores_cleared_reference_context_item_after_compaction`
## Stack
Depends on #28494.
## Description
This PR propagates shared rollout-budget exhaustion through the existing
`CodexErr::TurnAborted` task result.
Each thread records its model usage against the same ledger. Once the
ledger is exhausted, that usage update and all later usage updates
return `TurnAborted`. The task wrapper emits the normal aborted-turn
event and lifecycle instead of completing the turn.
This is intentionally a soft boundary: there is no cross-thread
`Op::Interrupt` fanout. An in-flight thread can finish its current
response before it observes the exhausted ledger, but every thread
aborts at its next usage-accounting boundary.
## Tests
The integration coverage verifies that:
- the response that exhausts the budget aborts its turn;
- a later response also aborts because the shared ledger remains
exhausted; and
- sub-agent usage draws from the same shared ledger; and
- local and remote-v2 compaction abort without retrying or emitting a
generic error.
Local checks:
- `just test -p codex-core
exhausted_budget_aborts_current_and_later_turns`
- `just test -p codex-core subagent_usage_draws_from_the_shared_budget`
- `just test -p codex-core
abort_regular_task_emits_marker_before_turn_aborted`
- `just test -p codex-core
compaction_budget_exhaustion_aborts_without_error_or_retry`
- `just fix -p codex-core`
- `just fmt`
- `git diff --check`
The full workspace test suite was not run locally.
## Why
Once multi-agent mode can be selected per turn, clients also need to
choose the initial selection when creating a thread and observe that
selection through lifecycle and settings APIs.
The selected value is intentionally distinct from the effective
model-visible value: no client selection is represented as `null`, even
though an eligible multi-agent v2 turn derives `explicitRequestOnly` as
its effective default.
## What changed
- Add the optional experimental `thread/start.multiAgentMode` parameter
and pass it through thread creation.
- Preserve an omitted initial value as an unset selection rather than
eagerly storing `explicitRequestOnly`.
- Apply an explicit `thread/start` selection to the first turn through
the session configuration established at thread creation.
- Restore the latest persisted effective mode as the selected baseline
on cold resume when rollout history contains one.
- Inherit the optional selected mode from a loaded parent when creating
related runtime threads.
- Return the current selected `multiAgentMode` from `thread/start`,
`thread/resume`, `thread/fork`, and thread settings, using `null` when
no mode is selected.
- Keep lifecycle reporting independent from model capability and feature
eligibility; core turn construction remains responsible for calculating
and persisting the effective mode.
## Not covered
- Clearing an existing loaded-session selection back to unset through
`turn/start`; omitted or `null` currently retains the session's
selection.
- A TUI control, slash command, or `config.toml` preference.
## Verification
- `CARGO_INCREMENTAL=0 just test -p codex-app-server-protocol`
- `CARGO_INCREMENTAL=0 just test -p codex-app-server multi_agent_mode`
The focused app-server coverage verifies explicit `thread/start`
initialization, first-turn prompting, nullable reporting for an omitted
selection, and retention of selections that are not currently
runtime-eligible.
## Stack
Stacked on #28685. This PR contains only the thread initialization and
lifecycle/settings API layer.
## Why
Multi-agent v2 currently carries an explicit-request-only delegation
rule in its static usage hint. That provides a safe default, but it
prevents clients from selecting proactive delegation per turn without
changing static guidance or rewriting prior model context.
This change makes delegation mode a session selection that can be
updated through `turn/start`, while deriving the effective model-visible
mode separately for each turn. Eligible multi-agent v2 turns remain
explicit-request-only unless proactive mode is both selected and
enabled.
## What changed
- Add the experimental `turn/start.multiAgentMode` parameter with
`explicitRequestOnly` and `proactive` values. Omission retains the
loaded session's current optional selection.
- Add the default-off `features.multi_agent_mode` feature gate. Eligible
multi-agent v2 turns use the selected mode when enabled; an unset
selection or disabled gate resolves to `explicitRequestOnly`.
- Treat mode prompting as inapplicable for multi-agent v1 and other
unsupported session configurations, producing no multi-agent mode
developer message rather than rejecting the turn.
- Move the explicit-request-only rule out of the static v2 usage hint
and into a bounded, tagged developer context fragment.
- Emit the effective mode in initial context and only when that
effective mode changes on later turns.
- Persist the effective mode in `TurnContextItem` as the durable
baseline for resume and context-update comparisons.
Historical rollout items are not rewritten. Later mode developer
messages establish the current rule incrementally.
## Not covered
- Initial selection through `thread/start` and selected-mode reporting
from thread lifecycle/settings APIs; those are isolated in the stacked
#28792.
- A TUI control or slash command for selecting the mode.
- Persisting a preferred mode to `config.toml`; selection remains
session/turn scoped.
- Changes to multi-agent concurrency limits, tool availability, or model
catalog capability declarations.
- Rewriting historical rollout prompt items. Cold resume restores the
latest persisted effective mode when available while leaving historical
developer messages intact.
## Verification
- `CARGO_INCREMENTAL=0 just test -p codex-core multi_agent_mode`
- Focused app-server coverage verifies that `turn/start.multiAgentMode`
produces proactive developer instructions for an eligible v2 turn.
## Stack
Followed by #28792, which adds `thread/start` initialization and
lifecycle/settings observability.
## Why
Remote v2 compaction can return replacement-history items without IDs.
Because replacement history is installed directly, those items bypass
normal history preparation and remain ID-less in later Responses
requests even when the `item_ids` feature is enabled.
## What changed
- Pass the active `TurnContext` into `replace_compacted_history`.
- When `item_ids` is enabled, assign missing IDs before installing and
persisting replacement history.
- Rebuild `CompactedItem` from the prepared history so live and
persisted replacement histories match.
- Add integration coverage requiring IDs on every ID-capable input item
in the initial, remote v2 compaction, and post-compaction requests.
## Test plan
- `just test -p codex-core response_item_ids`
- `just test -p codex-core websocket_v2_test_codex_shell_chain`
- `just test -p codex-core remote_compaction_parity_pre_turn_auto`
- `just test -p codex-app-server
thread_inject_items_adds_raw_response_items_to_thread_history`
## Why
Client-created response items enter history without IDs, so their
identity is lost across rollout persistence and resume. IDs should be
assigned once at the history-recording boundary, while IDs returned by
the server must remain unchanged.
The Responses API validates item IDs using type-specific prefixes.
Locally generated IDs therefore use the matching prefix plus a
hyphenated UUIDv7, keeping them valid while distinguishable from
server-generated IDs. Because this changes persisted history and
provider request shapes, the behavior is opt-in behind the
under-development `item_ids` feature. Compaction triggers remain request
controls whose API shape does not accept an ID.
## What changed
- Register the disabled-by-default `item_ids` feature and expose it in
`config.schema.json`.
- Make supported optional `ResponseItem` IDs serializable and expose
them in the generated app-server schemas.
- When `item_ids` is enabled, assign an ID during conversation-history
preparation if an item has no ID.
- Generate type-prefixed, hyphenated UUIDv7 IDs using the Responses API
item conventions.
- Preserve existing server IDs without rewriting them.
- Persist assigned IDs in rollouts and include them in subsequent
Responses requests.
- Remove the unsupported ID field from `CompactionTrigger` and document
why it has no ID.
- Add integration coverage for enabled ID persistence, preservation of
server IDs, and omission of generated IDs while the feature is disabled.
`prepare_conversation_items_for_history` is the single response-item ID
allocation boundary.
## Test plan
- `just test -p codex-features`
- `just test -p codex-core
response_item_ids_persist_across_resume_and_preserve_server_ids`
- `just test -p codex-core
non_openai_responses_requests_omit_item_turn_metadata`
- `just test -p codex-core
resize_all_images_prepares_failures_before_history_insertion`
- `just test -p codex-protocol`
- `just test -p codex-app-server-protocol`
- `just test -p codex-api azure_default_store_attaches_ids_and_headers`
## Why
The token-budget context currently identifies a context window by its
thread-local sequence number. A UUIDv7 gives the model a stable opaque
identity that remains fixed for a window and rotates when compaction or
`new_context` starts the next one.
## What changed
- Preserve the existing monotonic value as `window_number` and add a
UUIDv7 `window_id` to `CompactedItem`.
- Generate and rotate the UUID with auto-compaction window state,
persist it alongside the number, and reconstruct it on resume and
rollback.
- Accept legacy compacted rollout records where the numeric `window_id`
represented the window number.
- Use the UUID only in token-budget context; existing request headers
and metadata continue using `thread_id:window_number`.
## Testing
- `just test -p codex-protocol compacted_item::tests`
- `just test -p codex-core token_budget`
## Why
Make it possible to load AGENTS.md from remote exec-servers whose OS is
different than app-server.
## What
- keep `AGENTS.md` discovery and provenance as `PathUri`, with
root-aware parent and ancestor traversal
- expose lifecycle instruction sources as legacy app-server path strings
in events while retaining `PathUri` internally
- preserve and test mixed POSIX and Windows paths in model context and
TUI status output
- cover remote Windows loading end to end by seeding the Wine prefix
through host filesystem APIs
- fix bug in `PathUri`'s parent() implementation that would erase
Windows drive letters
Stacked on #28822.
## Summary
- add a host-injectable current-time provider with a built-in system
implementation
- record UTC developer reminders in history immediately before due model
requests
- keep cadence state per session and force a refresh after compaction
This does NOT include the app server client <-> server clock logic. This
PR is only for the reminder message & system clock that will be used in
prod.
## Testing
- `just test -p codex-core varlatency_`
- `just clippy -p codex-core -p codex-app-server -p codex-mcp-server -p
codex-thread-manager-sample`
- `just fmt`
## Stack
Depends on #28746. This PR implements shared rollout-budget accounting
and model-visible reminders using the configuration defined in #28746.
# Description / Main changes to Core:
`AgentControl` will now be the area where "rollout level" features &
accounting will have to live. It is incorrectly named for this
responsibility, but I think it can hold all the necessary shared state &
features (rollout token budget, mutliple thread interruption
responsibilitym etc)
In this PR, we have one "token ledger" that each thread will subtract
from when sampling. The "charge" will occur when response.completed() is
done and the calculation will be done on the responses api usage
carrier. The calculation will weigh sampling and pre-fill tokens as
specified.
Every time the budget crosses the configured reminder threshold, a
developer message is appended before the thread's next request
This remaining budget will _always_ be restated/reminded after a
compaction event.
Expiration and fan-out interruption will be in the stacked follow-up
(and also live in Agent Control).
## Reminders
"You have weighted {session_tokens_left} tokens left in the shared
session token budget."
The first request in each thread context receives the current remainder.
Later reminders are emitted after aggregate weighted usage crosses a
configured interval. If several intervals are crossed before a thread
sends another request, Core inserts one reminder with the latest
remainder.
Compaction response usage is charged before the next context starts. The
next reminder is appended after the compaction summary, leaving the
initial context content stable.
## Tests
Integration coverage verifies:
- weighted output and non-cached input accounting
- initial and periodic reminders
- shared accounting between a root and sub-agent
- post-compaction remainder and message placement
Local checks:
- `just fmt`
- `just test -p codex-core rollout_budget`
- `git diff --check`
The full workspace test suite was not run locally.
## Summary
- keep context injection on a single ContextContributor trait
- split context injection into thread-scoped and turn-scoped
contribution methods
- wire turn-scoped fragments into initial context assembly so extensions
can contribute context from turn-local state
## What
Built on the realtime speech-control plumbing merged in #27917.
- Add optional `codexResponseHandoffPrefix` to `thread/realtime/start`.
- Apply that prefix only to automatic V1 commentary sent through
`conversation.handoff.append`; final answers remain unprefixed.
- Add opt-in `clientManagedHandoffs`. When true, core suppresses
automatic response handoffs and completion output so delivery is
controlled by explicit client append APIs.
- Preserve existing automatic behavior by default.
`codexResponsesAsItems: true` continues to select item routing when
client-managed mode is disabled.
## Why
Voice clients need two delivery policies: automatic background context
with silent commentary instructions and fully client-owned handoffs.
Phase-aware prefixing keeps routine commentary silent without
suppressing the final answer, while client-managed mode lets an app
decide exactly which updates to append.
## Validation
- `just fmt`
- `cargo test -p codex-app-server-protocol
serialize_thread_realtime_start`
- `RUST_MIN_STACK=16777216 cargo test -p codex-core --test all
conversation_handoff_persists_across_item_done_until_turn_complete`
- `RUST_MIN_STACK=16777216 cargo test -p codex-app-server --test all
webrtc_v1_client_managed_handoffs_disable_automatic_output`
- `RUST_MIN_STACK=16777216 cargo test -p codex-app-server --test all
webrtc_v1_final_automatic_handoff_omits_silent_prefix`
- `cargo build -p codex-cli --bin codex`
- Local Codex Apps compatibility check: 43 focused webview tests passed,
and a live voice session routed through the source-built app-server.
The explicit `RUST_MIN_STACK` avoids a macOS Tokio test-worker stack
overflow seen with the default test environment.
## Why
A durable realtime voice orchestrator can reconnect and resume through
multiple fresh `Session` instances. Realtime handoffs were using the
Session-local `auto-compact-N` counter as their turn identity, but that
counter restarts at zero for every resumed Session. The durable thread
could therefore accumulate duplicate turn IDs, violating the uniqueness
assumptions made by app-server and web clients. In Codex Apps, a new
delegated response stream could be attached to an older turn with the
same ID, placing live output higher in history and putting turn-scoped
actions at risk.
Persisted rollout and reconstructed model-context order were already
correct because raw response items remain append-only and chronological.
This change restores unique identity for reconstructed and live turn
surfaces.
## What changed
- Generate a UUIDv7 specifically for each realtime-routed delegation.
- Leave the existing `auto-compact-N` identity path unchanged for actual
internal auto-compaction turns.
- Extend the inbound realtime handoff integration test to require a UUID
turn ID from `turn/started`.
## Verification
- `just test -p codex-core inbound_handoff_request_starts_turn`
- `just fix -p codex-core`
- `just fmt`
## Why
Command approval cache keys included the command and working directory,
but not the execution environment. An approval for `/workspace` locally
could therefore be reused for the same command and path on an executor.
## What changed
- Include the selected environment ID in shell and unified-exec approval
cache keys.
- Carry that ID through the normal command approval request so clients
can show which environment is being approved.
- Expose the environment through app-server as a required nullable
`environmentId` and show it in the inline TUI approval prompt.
- Keep older recorded approval events compatible when the environment is
absent.
For example, `echo ok` in local `/workspace` and `echo ok` in executor
`/workspace` now produce different approval keys and separate prompts.
## Scope
This PR does not change network approvals, Guardian review actions, MCP
elicitation, full-screen TUI rendering, or environment-ID validation.
Remote `shell_command` execution itself remains in #28722; this PR only
makes its approval key environment-aware.
## Why
Host skill discovery was still exposed as a manager even though it is a
process-owned service shared by sessions, the app-server catalog, and
file-watcher invalidation. The skills extension also consumed an ad hoc
loaded-skills wrapper instead of a named immutable snapshot.
## What changed
- replace `SkillsManager` with concrete `SkillsService`
- make the service cache and return immutable `HostSkillsSnapshot`
values
- migrate the skills extension host provider to the snapshot boundary
- migrate app-server catalog, watcher, and invalidation paths to the
service
This keeps the service limited to host discovery, caching, roots, and
invalidation. Catalog rendering and invocation remain extension
responsibilities for the next stacked change.
## Why
`TurnContext` had accumulated dead fields and cached projections of
values already owned by its per-turn `Config` or `ModelInfo`. Keeping
both copies made ownership unclear and allowed artificial split-brain
states, such as a compatibility hash differing from the model metadata
it came from.
`Prompt` similarly carried a write-only personality after personality
selection had already been materialized into its base instructions.
This makes the canonical owner explicit: configuration-backed values
come from `config`, model-derived values come from `model_info`, and
prompts contain only data consumed by request construction.
## What changed
- Remove the unused `ghost_snapshot`, `codex_self_exe`, and
`thread_source` fields.
- Remove duplicate `comp_hash`, `truncation_policy`, `features`,
`shell_environment_policy`, `codex_linux_sandbox_exe`, `compact_prompt`,
and `tool_mode` fields.
- Read those values directly from `TurnContext::config` or
`TurnContext::model_info` at their consumers.
- Remove the write-only `Prompt::personality` field and its constructor
assignments.
- Preserve review-turn inheritance of the parent turn's shell policy,
Linux sandbox executable, and compact prompt through the review config.
## Testing
- `cargo check -p codex-core --tests`
## Why
#28152 jumped the gun on moving the rollout format to store URIs, and
would likely break compat with some features that don't go through the
same types as the core logic.
## What
Make `TurnContextItem.cwd` an `AbsolutePathBuf` again, remove test added
for `PathUri` serialization in rollouts. Also drops a bunch of error
paths that are no longer needed.
## Why
Model-visible `<environment_context>` should match the environment of
the executor, not of the app server.
Stacked on #28146.
## What
- Keep selected environment cwd values as `PathUri` while building
environment context.
- Render cwd text using the path convention represented by the URI, with
the canonical URI as a fallback.
- Preserve compatibility with legacy `TurnContextItem.cwd` values when
reconstructing and diffing context.
- Extend the Wine-backed remote Windows test to assert that the model
sees `powershell` and `C:\windows`.
Summary\n- Await endpoint recommendation selection while constructing
each authenticated turn, removing the first-turn cache race.\n- Snapshot
and filter endpoint candidates once per turn, then use that same set for
the bounded contextual user fragment, tool exposure, and exact install
validation.\n- Keep recommendation selection ephemeral: do not persist
recommendation state in or gate resumed threads on prior context.\n-
Hide the legacy list tool in endpoint mode and preserve legacy discovery
unchanged when the endpoint is disabled or unavailable.\n- Keep remote
plugin and connector app identities out of model-visible context and
attach them only to Codex-owned elicitation metadata.\n\nStack\n- 3/4,
based on #28400.\n- Endpoint client and cache: #28399.\n- Generalized
suggestion presentation: #28400.\n- Install-schema follow-up:
#28403.\n\nValidation\n- \n- \n- \n- \n- Full : 2,649 passed and 88
environment-dependent tests failed because this sandbox cannot write ,
nest Seatbelt, or locate auxiliary test binaries.
## Why
When a subagent exhausts its retries, it emits an `Error`, but the
generic task lifecycle then emits `TurnComplete(None)`. That completion
used to overwrite the subagent's `Errored` status with
`Completed(None)`, so the parent received an empty completion
notification.
This made a failed child look indistinguishable from a child that
completed without an answer. In unattended or long-running multi-agent
work, the root could silently continue without knowing that delegated
work failed or how to restart it.
## Behavior
Before, a terminal stream failure was reduced to an empty completion:
```text
<subagent_notification>
{"agent_path":"/root/worker","status":{"completed":null}}
</subagent_notification>
```
Now the parent receives the actual terminal error, bounded to 1,000
tokens, together with an actionable recovery hint:
```text
<subagent_notification>
{
"agent_path": "/root/worker",
"status": {
"errored": "stream disconnected before completion: stream closed before response.completed"
},
"next_action": "This agent's turn failed. If you still need this agent, use `followup_task` to give it another task."
}
</subagent_notification>
```
The notification remains queue-only: it does not wake the root or replay
the failed request. The root sees it at the next sampling boundary and
can use `followup_task` to start a new turn for that agent.
## What changed
- Added terminal-error precedence to the [agent status
reducer](https://github.com/openai/codex/blob/e95fcfe2bb6a02f1a75650afa20048859f556511/codex-rs/core/src/agent/status.rs#L23-L34),
so a closing `TurnComplete` cannot erase an immediately preceding
`Errored` status.
- Made MultiAgentV2 completion forwarding use the retained session
status instead of re-deriving `Completed(None)` from the final event.
- Extended the [subagent notification
fragment](https://github.com/openai/codex/blob/e95fcfe2bb6a02f1a75650afa20048859f556511/codex-rs/core/src/context/subagent_notification.rs#L6-L60)
with a `next_action` for terminal errors and a hard cap on model-visible
error text.
- Kept successful completions and interrupted turns unchanged.
## Verification
- Added a status-reducer test proving that `Errored` survives the
trailing `TurnComplete`.
- Added an integration test that exhausts a subagent's stream retries
and verifies the exact `agent_message` delivered to the parent,
including the error and `followup_task` guidance.
- Re-ran the existing successful-completion and interrupted-turn
notification tests.
## Why
Multi-agent v2 messages need a consistent, model-visible envelope that
identifies what kind of interaction occurred, who sent it, and which
agent it targets. Previously, encrypted deliveries exposed only
`encrypted_content`, while child completion used the legacy
`<subagent_notification>` shape. That meant the client could not
consistently present `NEW_TASK`, `MESSAGE`, and `FINAL_ANSWER` using the
same format.
This change adds the routing envelope as plaintext while keeping task
and message payloads encrypted. No new Responses API field is required:
an encrypted delivery is represented as an `input_text` header
immediately followed by its existing `encrypted_content` item.
Every envelope now follows this shape:
```text
Message Type: <NEW_TASK | MESSAGE | FINAL_ANSWER>
Task name: <recipient agent path>
Sender: <author agent path>
Payload:
<message payload>
```
## Message types
### `NEW_TASK`
`NEW_TASK` is used when the recipient should begin a new turn, including
an initial `spawn_agent` task and a later `followup_task`.
For a root agent spawning `/root/worker`, the request contains a
plaintext envelope followed by the encrypted task:
```json
{
"type": "agent_message",
"author": "/root",
"recipient": "/root/worker",
"content": [
{
"type": "input_text",
"text": "Message Type: NEW_TASK\nTask name: /root/worker\nSender: /root\nPayload:\n"
},
{
"type": "encrypted_content",
"encrypted_content": "<encrypted task payload>"
}
]
}
```
Conceptually, the model receives:
```text
Message Type: NEW_TASK
Task name: /root/worker
Sender: /root
Payload:
Review the authentication changes and report any regressions.
```
### `MESSAGE`
`MESSAGE` is used for a queued `send_message` delivery. It communicates
with an existing agent without starting a new turn.
For `/root/worker` reporting progress to the root agent, the request
contains:
```json
{
"type": "agent_message",
"author": "/root/worker",
"recipient": "/root",
"content": [
{
"type": "input_text",
"text": "Message Type: MESSAGE\nTask name: /root\nSender: /root/worker\nPayload:\n"
},
{
"type": "encrypted_content",
"encrypted_content": "<encrypted message payload>"
}
]
}
```
Conceptually, the model receives:
```text
Message Type: MESSAGE
Task name: /root
Sender: /root/worker
Payload:
The protocol tests pass; I am checking the resume path now.
```
### `FINAL_ANSWER`
`FINAL_ANSWER` is emitted when a child agent reaches a terminal state
and reports its result to its parent. Completion payloads are already
available locally, so the complete envelope is represented as plaintext
rather than as a plaintext header plus encrypted content.
For `/root/worker` completing work for the root agent, the request
contains:
```json
{
"type": "agent_message",
"author": "/root/worker",
"recipient": "/root",
"content": [
{
"type": "input_text",
"text": "Message Type: FINAL_ANSWER\nTask name: /root\nSender: /root/worker\nPayload:\nNo regressions found."
}
]
}
```
The model-visible form is:
```text
Message Type: FINAL_ANSWER
Task name: /root
Sender: /root/worker
Payload:
No regressions found.
```
Errored, shut down, and missing agents also use `FINAL_ANSWER`, with a
terminal-status description in the payload.
## What changed
- Render `NEW_TASK` or `MESSAGE` in
`InterAgentCommunication::to_model_input_item`, based on whether the
encrypted delivery starts a turn.
- Replace the multi-agent v2 `<subagent_notification>` completion
payload with a model-visible `FINAL_ANSWER` envelope.
- Document `Task name`, `Sender`, and `Payload` consistently in the
multi-agent developer instructions.
- Prevent local-only history projections from treating an encrypted
message's plaintext header as the complete assistant message.
- Preserve rollout-trace interaction edges when an agent message
contains both plaintext and encrypted content.
Legacy multi-agent behavior remains unchanged.
## Verification
- `just test -p codex-protocol`
- `just test -p codex-rollout-trace`
- `just test -p codex-web-search-extension`
- `just test -p codex-core
encrypted_multi_agent_v2_spawn_sends_agent_message_to_child`
- `just test -p codex-core
plaintext_multi_agent_v2_completion_sends_agent_message`
- `just test -p codex-core
multi_agent_v2_followup_task_completion_notifies_parent_on_every_turn`
- `just test -p codex-core
multi_agent_v2_completion_queues_message_for_direct_parent`
## Why
User shell commands still read the legacy turn cwd and session shell
even though execution context is now owned by selected turn
environments. App-server also defines `thread/shellCommand` as a
local-host escape hatch, so it must use an available local environment
even when a remote environment is primary.
## What changed
- Add `ResolvedTurnEnvironments::local()` to find the selected local
environment.
- Resolve the user shell command cwd and shell from that local
`TurnEnvironment`.
- Emit the standard `shell is unavailable in this session` error when no
selected local environment or resolved local shell is available.
- Add an integration test covering `/shell` without a local environment.
## Test plan
- `just test -p codex-core
user_shell_command_without_local_environment_emits_error`
## Why
Shell snapshots are currently session-scoped even though shell and cwd
are properties of a selected turn environment. That makes snapshot
refresh depend on separate session-cwd plumbing, prevents retained
environments from retaining their snapshot work, and can make snapshot
construction use a different shell than command execution.
This follows #27955 by making the retained thread-environment service
own environment snapshot lifecycles. Session configuration remains the
requested selection state, while `ThreadEnvironments` remains the source
of successfully resolved environments.
## What changed
- Configure the shell-snapshot builder before initial environment
resolution.
- Start each local environment snapshot task when its `TurnEnvironment`
is built and retain that shared task while environment ID and cwd still
match.
- Inherit retained environment snapshots into spawned child threads.
- Carry the selected `TurnEnvironment` through shell runtimes so
snapshot construction and command execution use the same
environment-specific shell and cwd.
- Load project instructions and warm plugins/skills after initial
environment resolution.
- Continue decoding invalid UTF-8 instruction files lossily without
emitting a startup warning.
- Keep requested selections in `SessionConfiguration`; failed or
duplicate resolutions only affect the resolved environment snapshot.
## Validation
- `cargo check -p codex-core --tests`
- `just test -p codex-home instructions` (6 passed)
- Focused environment, instruction, shell-snapshot, and user-shell tests
(84 passed)
- Focused shell-snapshot, user-shell, and unified-exec tests (126
passed; two event-timing tests passed on retry)
## Why
Progress towards letting app-server and exec-server run on different
platforms, specifically for sandbox configuration.
## What
- Make the filesystem path containment hierarchy generic, defaulting to
`AbsolutePathBuf` for now.
- Have clients specify `AbsolutePathBuf` or `PathUri` directly where
needed.
- Use `PathUri` throughout exec-server filesystem protocol and trait
boundaries.
- Implement `From` for conversion to path URIs and `TryFrom` for
fallible conversion to absolute paths through the generic type
hierarchy.
## Why
Selected execution environments are thread-scoped resources, but startup
and turn construction repeatedly resolved their IDs and working
directories. That discarded existing environment handles and shell
metadata even when a selection had not changed.
Session configuration updates also need to affect future turns without
changing the resolved environment set already captured by a running
turn.
## What changed
- Create a `ThreadEnvironments` service inside `Codex` from the spawned
`EnvironmentManager` and raw environment selections, then store it on
`SessionServices`.
- Split service construction from `update_selections`, allowing session
configuration updates to mutate the resolved set in place.
- Retain an existing `TurnEnvironment` when its environment ID and
working directory match; resolve only added or changed selections and
remove selections that are no longer present.
- Normalize duplicate IDs by keeping the first selection and skip
individual selections that fail to resolve instead of rejecting the
entire update.
- Give each `TurnContext` a cloned `TurnEnvironmentSnapshot`, so later
session configuration updates affect future turns without rewriting an
active turn.
- Reuse the service-owned environment manager and resolved snapshot for
startup work, MCP initialization, and child-thread spawning instead of
flowing resolved environments through spawn arguments.
## Test plan
- `cargo check -p codex-core --tests`
- `just test -p codex-core environment_selection`
- `just test -p codex-core turn_environments`
- `just test -p codex-core
session_update_settings_does_not_rewrite_sticky_environment_cwds`
- `just test -p codex-core
default_turn_does_not_overlay_legacy_fallback_cwd_onto_stored_thread_environments`
## Description
This PR adds an optional `metadata` field to `ResponseItem` for
Responses API calls. Only mechanical plumbing, no actual values
populated and sent yet. Turns out just adding a new field to
`ResponseItem` has quite a large blast radius already.
This change is backwards compatible because `metadata` is optional and
omitted when absent, so existing response items and rollout history
without it still deserialize and requests that do not set it keep the
same wire shape. For provider compatibility, we strip out `metadata`
before non-OpenAI Responses requests so Azure and AWS Bedrock never see
this field.
My followup PR here will actually make use of it to start storing and
passing along `turn_id`: https://github.com/openai/codex/pull/28360
## What changed
- Added `ResponseItemMetadata` with optional `turn_id`, plus optional
`metadata` on Responses API item variants and inter-agent communication.
- Preserved item metadata through response-item rewrites such as
truncation, missing tool-output synthesis, compaction history
rebuilding, visible-history conversion, rollout/resume, and generated
app-server schemas/types.
- Strip item metadata from non-OpenAI Responses requests while
preserving it for OpenAI-shaped requests.
- Updated the mechanical fixture/test construction churn required by the
new optional field.
## Why
`wait_agent` can block for a long timeout while waiting for sub-agent
mailbox activity. Although same-turn user steer is accepted during that
tool call, the input remains pending until the wait returns, so an
explicit request to change direction can appear unresponsive.
## What changed
- Notify active `wait_agent` calls when user input is steered into the
current turn.
- Check for already-pending steer input when subscribing so input that
races with tool startup is not missed.
- Distinguish mailbox activity, steered input, and timeout outcomes,
returning `Wait interrupted by new input.` for the steer path.
- Update the `wait_agent` tool description to document the early-return
behavior.
## Testing
- `just test -p codex-core input_queue_`
- `just test -p codex-core wait_agent`
The coverage includes steer notification before and after subscription,
plus an end-to-end test that verifies the interrupted wait result and
steered user input are both included exactly once in the follow-up model
request.
## Why
Shell snapshot lifecycle state was split between `Shell` and
`SessionServices`: `Shell` carried the receiver while session code
exposed and forwarded the raw sender. That coupled shell identity to
mutable snapshot state and made refresh, inheritance, and file lifetime
harder to reason about.
## What changed
- make each `Arc<ShellSnapshot>` represent one cwd-specific snapshot
generation
- store the active generation in `SessionServices` with `ArcSwapOption`
- have construction start the background build and expose only a
cwd-validated snapshot path
- use `ShellSnapshotFile` ownership to delete snapshot files
automatically
- pass snapshot paths explicitly to shell runtimes instead of storing
snapshot state on `Shell`
- preserve inherited and in-flight generations by pinning their `Arc`
while they are in use
## Test plan
- `cargo check -p codex-core --lib`
- `just test -p codex-core 'shell_snapshot::tests'`
- `just test -p codex-core
shell_command_snapshot_still_intercepts_apply_patch`
- `just test -p codex-core
shell_snapshot_deleted_after_shutdown_with_skills`
## Why
Next slice needed to make progress on the `remote_env_windows` test is
to support passing a Windows cwd for the remote environment and using
that environment's native shell. This lets the test run a real Windows
process instead of only recording an early path or shell mismatch.
## What
- change `TurnEnvironmentSelection.cwd` from `AbsolutePathBuf` to
`PathUri`
- convert local cwd values to URIs when constructing selections
- preserve a remote primary cwd instead of replacing it with the local
legacy fallback
- prefer the selected environment's discovered shell for unified exec,
falling back to the session shell when unavailable
- convert back to a host-native absolute path at current native-only
consumer boundaries
- reject or deny unsupported foreign cwd values at the existing
request-permissions boundary, with TODOs for its future migration
- extend the hermetic Wine test to execute Windows PowerShell in
`C:\windows` and verify successful process completion
- record the current app-server rejection against the same Wine-backed
remote Windows fixture when its cwd is supplied as a native Windows path
## Why
We have some large gaps in our thread start, resume, and pre-sampling
traces that make it hard to tell where latency is coming from.
## What Changed
- Added coarse spans around thread start/resume, turn context
construction, rollout reconstruction, skill/plugin loading, and tool
preparation.
- Added a breakdown of discoverable-tool preparation across connector
loading, plugin discovery, and local plugin details.
## Testing
- `cargo check -p codex-app-server -p codex-core -p codex-core-skills -p
codex-core-plugins`
- Built the app-server locally and exercised thread start, first turn,
follow-up turn, server restart, thread resume, and a resumed turn.
## Summary
- store MCP OAuth credentials in the configured auth credential backend
- support encrypted-local OAuth storage, including legacy keyring
migration
- propagate the credential backend through MCP refresh, session, CLI,
and app-server paths
## Stack
1. #27504 — config and feature flag
2. #27535 — auth-specific secret namespaces
3. #27539 — encrypted CLI auth storage
4. this PR — encrypted MCP OAuth storage
This is a parallel review stack; the original #17931 remains unchanged.
## Tests
- `just test -p codex-rmcp-client` (the transport round-trip test passed
after building the required `codex` binary and retrying)
- `just test -p codex-mcp`
- `just test -p codex-app-server
refresh_config_uses_latest_auth_keyring_backend`
- `just test -p codex-core
refresh_mcp_servers_is_deferred_until_next_turn`
- `just test -p codex-cli mcp`
- `just fix -p codex-rmcp-client -p codex-mcp -p codex-core -p codex-cli
-p codex-app-server -p codex-protocol`
- `just bazel-lock-check`
## Why
Multi-agent v2 `send_message` deliveries already reach the receiving
model as typed `agent_message` items with encrypted content.
Child-completion notifications are generated by Codex itself, so their
content is plaintext and previously fell back to a serialized JSON
envelope inside an assistant message.
With plaintext `input_text` supported for `agent_message`, both delivery
paths can use the same model-visible type while preserving explicit
author and recipient metadata.
## What changed
- add plaintext `input_text` support to `AgentMessageInputContent` and
regenerate the affected app-server schemas
- preserve `InterAgentCommunication` as structured mailbox input instead
of converting it to assistant text
- record delivered communications as typed `agent_message` history items
- persist a dedicated rollout item so local delivery metadata such as
`trigger_turn` remains available without leaking into the Responses
request
- reconstruct typed agent messages on resume and preserve fork-turn
truncation behavior
- remove request-time assistant-content parsing
- preserve plaintext and encrypted inter-agent deliveries in stage-one
memory inputs
- normalize and link plaintext and encrypted agent messages in rollout
traces without treating inbound messages as child results
- cover the real MultiAgent V2 child-completion path end to end with
deterministic mailbox synchronization
## Verification
- `just test -p codex-core
plaintext_multi_agent_v2_completion_sends_agent_message`
- `just test -p codex-core input_queue_drains_mailbox_in_delivery_order
record_initial_history_reconstructs_typed_inter_agent_message
fork_turn_positions_use_inter_agent_delivery_metadata`
- `just test -p codex-memories-write
serializes_inter_agent_communications_for_memory`
- `just test -p codex-rollout-trace
agent_messages_preserve_routing_and_content
sub_agent_started_activity_creates_spawn_edge`
- `just test -p codex-rollout-trace
agent_result_edge_falls_back_to_child_thread_without_result_message`
- `just test -p codex-protocol -p codex-rollout -p
codex-app-server-protocol`
## Why
`selectedCapabilityRoots` belongs to one thread, but MCP contributors
previously received only the global Codex config. That left no clean way
for a selected executor capability to contribute MCP servers to its own
thread.
## What this PR does
- Gives MCP contributors a small context containing the config and, for
a running thread, its frozen host-seeded inputs.
- Uses the same thread inputs during startup, status queries, refreshes,
and skill dependency checks.
- Keeps threadless MCP operations and the existing hosted Apps behavior
unchanged.
- Adds coverage showing that two threads resolve independent
registrations and that later lifecycle mutations do not change the
frozen MCP inputs.
This PR does not discover plugin manifests, add MCP servers, or launch
anything new. It only establishes the thread-scoped registration
boundary.
## Follow-ups
- Resolve selected executor plugin roots through their owning
environment filesystem.
- Convert their stdio MCP declarations into environment-bound
registrations and add an executor MCP end-to-end test.
## Verification
- `just fmt`
- `cargo check --tests -p codex-protocol -p codex-extension-api -p
codex-mcp-extension -p codex-core -p codex-app-server`
Tests and Clippy were not run.
## Why
We already have the machinery to support multiple environments on a
single thread, but we only show the model the contents of `AGENTS.md`
files in the primary environment.
We should show the model all of the relevant project instructions when
we know there's more than one environment.
## Known Gaps
As discussed in the RFC, this implementation:
1. doesn't handle environments being added/removed to/from the thread
after its creation
2. it doesn't enforce an aggregate context budget across environments,
and instead applies the configured project maximum independently to each
environment
## Implementation
- Discover project instructions in environment order with an independent
byte budget per environment and preserve source provenance/order.
- Keep the legacy fragment byte-for-byte when exactly one environment
contributes project instructions; use environment-labeled sections when
two or more environments contribute.
- Freeze the complete rendered fragment in `LoadedAgentsMd`, insert it
directly into requests, and recognize both layouts in contextual and
memory filtering.
- Add exact rendering, independent-budget, source-order,
creation-snapshot, and consumer coverage without changing app-server
schemas.
## Why
`request_user_input` is moving beyond its original plan-mode-only
workflow, and future default/goal-mode usage needs a way for the model
to ask helpful but non-blocking questions without forcing the turn to
wait forever. This PR adds an explicit `autoResolutionMs` contract so a
later client/runtime change can auto-resolve unanswered prompts after a
bounded window while leaving truly blocking questions unchanged.
This is contract plumbing only; it does not implement the client-side
timer or auto-selection behavior, and the model-facing description
treats the field as reserved unless the current runtime explicitly
supports auto-resolution.
## What Changed
- Added optional `autoResolutionMs` to the model-facing
`request_user_input` args and core `RequestUserInputEvent`.
- Added model-facing schema text for `autoResolutionMs` while marking it
reserved for runtimes that explicitly support auto-resolution.
- Bounds `autoResolutionMs` to `60_000..=240_000` ms during argument
normalization by clamping out-of-range model-provided values.
- Propagated the field through app-server v2
`ToolRequestUserInputParams`, app-server request forwarding, generated
TypeScript, and JSON schema fixtures.
- Updated app-server, core, protocol, and TUI call sites/tests so
omitted values preserve existing `None`/`null` behavior and coverage
verifies a `Some(60_000)` round trip.
## Verification
- `just test -p codex-app-server-protocol`
- `just test -p codex-core request_user_input`
- `just test -p codex-app-server request_user_input_round_trip`
- `just test -p codex-tui request_user_input`
- `just test -p codex-protocol`
## Why
Codex app-server latency traces do not granularly cover turn task
startup and inter-request handoffs. These spans help attribute time
across task execution, startup prewarm, in-flight tool completion, and
rollout persistence.
## What changed
- Add `session_task.run` spans around task execution and
`session_task.flush_rollout` around flushing pending conversation
transcript writes to durable storage
- Add `regular_task.prepare_run_turn` around regular-turn startup (Send
the `TurnStarted` event, reset turn-specific reasoning state, and
resolve any startup prewarm)
- Add `startup_prewarm.resolve` around waiting for background session
prewarming to finish, fail, time out, or be cancelled
- Add a function-level trace span around draining in-flight tool calls
(Wait for tool calls to complete, record tool result in conversation
history, and other bookkeeping)
## Verification
Trigger Codex rollout and observe new spans are included
## Why
The token budget full-context fragment identifies the current context
window, but not the thread that owns that window. Including the thread
id makes the initial context-window metadata self-contained, and
`get_context_remaining` also needs to be usable from Code Mode without
forcing callers to parse the model-facing fragment string.
## What changed
- Include the session thread id in the initial `<token_budget>` context
fragment.
- Expose `get_context_remaining` as a Code Mode nested tool while
keeping `new_context` direct-model-only.
- Keep direct model-facing `get_context_remaining` output as the
existing `<token_budget>` text fragment.
- Return only `tokens_left` from the Code Mode structured result for
`get_context_remaining`.
- Update token-budget integration tests and add Code Mode coverage for
the structured result.
## Verification
- `just test -p codex-core token_budget`
- `just test -p codex-core
code_mode_get_context_remaining_returns_structured_result`
- `just test -p core_test_support redacted_text_mode_normalizes_uuids`
## Why
We want to remove implicit use of `$CODEX_HOME` from `codex-core` and
make embedders responsible for supplying user-level instructions. This
also ensures user instructions load when no primary environment is
selected.
## What changed
Stacked on #27415, which makes `codex exec` surface thread-scoped
runtime warnings.
- Added `UserInstructionsProvider` to `codex-extension-api`, with
absolute source attribution and recoverable loading warnings.
- Added `codex-home` with the filesystem-backed provider for
`AGENTS.override.md` and `AGENTS.md`, preserving precedence, fallback,
trimming, lossy UTF-8 handling, and the existing uncapped global
instruction size.
- Removed global instruction loading from `Config` and require
`ThreadManager` callers to inject a provider.
- Load provider instructions once for each fresh root runtime, including
runtimes without a primary environment. Running sessions retain their
snapshot, while child agents inherit the parent snapshot without
invoking the provider.
- Keep provider instructions separate while loading project `AGENTS.md`,
then assemble the model-visible instructions with the existing ordering,
source attribution, warning, and turn-context behavior.
- Wired the Codex home provider through the CLI, app server, MCP server,
core facade, and thread-manager sample.
## Validation
- `just test -p codex-home -p codex-extension-api`
- `just test -p codex-core agents_md`
- `just test -p codex-core guardian`
- `just test -p codex-app-server
thread_start_without_selected_environment_includes_only_global_instruction_source`
- `just test -p codex-exec warning`
- `just bazel-lock-check`
## Why
#27198 made the extension-owned `codex_apps` MCP connection the hosted
plugin runtime, but its `mcp/skill` resources still bypassed the skills
extension. App-server could list and read those resources through
generic MCP APIs, but a thread with no selected environment did not
expose them in the model's skills catalog or load their `SKILL.md`
through `$skill`.
Hosted skills should stay remote while using the same typed catalog,
source authority, deduplication, bounded contextual catalog, and
selected-skill prompt injection as host and executor skills. They should
not be downloaded or exposed as ambient filesystem paths.
## What changed
- Add a session-scoped `McpResourceClient` over the replaceable MCP
connection manager so resource list/read calls follow startup and
refresh replacements.
- Add a `BackendSkillProvider` that pages `codex_apps` resources,
accepts bounded and validated `mcp/skill` entries, and reads a selected
skill's `SKILL.md` through the same MCP connection.
- Register the remote provider in app-server and include it in the
skills catalog even when a thread has no selected capability roots or
executor.
- Contribute hosted skill metadata through the bounded
`AvailableSkillsInstructions` developer-context path, exclude remote
entries from per-turn catalog injection, and classify `<skills>`
messages as contextual developer content so rollback can trim and
rebuild them correctly.
## Testing
- Extend the app-server MCP resource integration test with
`environments: []` to exercise two-page discovery, filter a
non-`mcp/skill` resource, verify the escaped developer catalog entry and
user-role `<skill>` fragment containing the fetched `SKILL.md`, and
preserve generic MCP resource reads.
- Add core event-mapping coverage that classifies `<skills>` developer
messages as contextual history.
## Summary
- snapshot `comp_hash` into `TurnContext` when the turn is created and
use that snapshot as the downstream source of truth
- persist the turn hash in rollout context and recover it into
previous-turn settings during resume and fork replay
- compact existing history with the previous model only when both
adjacent turns provide hashes and the values differ
- record `comp_hash_changed` as the compaction reason
- cover ordinary transitions, resume, and missing-hash compatibility
with end-to-end tests
## Why
History produced under one compaction-compatible model configuration may
not be safe to carry directly into another. Compacting at the turn
boundary converts that history before context updates and the new user
message are added. Persisting the turn snapshot in `TurnContextItem`
makes the same protection work after resuming a rollout.
A missing hash is not treated as evidence of incompatibility. `None →
Some`, `Some → None`, and `None → None` do not trigger compaction; only
`Some(previous) → Some(current)` with unequal values does.
## Stack
- depends on #27532
- #27532 is based directly on `main`
## Testing
- `just test -p codex-core pre_sampling_compact_` — 6 passed
- `just test -p codex-core
turn_context_item_uses_turn_context_comp_hash_snapshot` — passed
- `just fix -p codex-core -p codex-protocol -p codex-analytics -p
codex-models-manager`
## Why
The token budget feature tells the model how much room remains in the
current context window. When the model decides the current window is no
longer useful, it needs a way to ask Codex to start over with a fresh
context window without spending tokens on a compaction summary.
This PR adds that model-requestable escape hatch on top of #27438.
## What changed
- Added a direct-model-only `new_context` tool behind
`Feature::TokenBudget`.
- Stores the tool request on `AutoCompactWindow` and consumes it after
sampling so the next follow-up request in the same turn starts in the
new window.
- Starts the new window as a no-summary compaction checkpoint that
contains only fresh initial context, not preserved conversation history.
- Keeps the new window aligned with token-budget startup context,
including the `Current context window Z` message.
- Added integration coverage and a snapshot showing the same-turn
`new_context` flow into a fresh full-context follow-up request.
## Validation
- `just test -p codex-core token_budget`
## Why
The model should be able to see bounded context-window budget metadata
when the `token_budget` feature is enabled. The full-window message is
only injected with full context, while normal turns get a smaller
follow-up only when reported usage first crosses a budget threshold.
## What changed
- Added the `TokenBudget` feature flag.
- Added `<token_budget>` developer fragments for full context-window
metadata and current-window remaining tokens.
- Inserted the threshold message during normal turn handling by
comparing token usage before and after sampling, avoiding persistent
threshold bookkeeping.
- Added core integration coverage for full-context-only metadata and
25/50/75 percent threshold messages.
## Verification
- `just test -p codex-core token_budget`
- `git diff --check`
## Summary
Adds complete client-side image preparation behind the default-off
`resize_all_images` feature flag.
When enabled, local image producers defer decoding and resizing. Images
are prepared centrally before insertion into conversation history,
covering user input, `view_image`, and structured tool-output images.
## Behavior
- Processes base64 `data:` images in messages and function/custom tool
outputs.
- Leaves non-data URLs, including HTTP(S) URLs, unchanged.
- Applies image-detail budgets:
- `high` and omitted: 2048px maximum dimension and 2.5K 32px patches.
- `original`: 6000px maximum dimension and 10K 32px patches.
- `auto`: uses the same 2048px / 2.5K-patch budget as high.
- `low`: unsupported and replaced with an actionable placeholder.
- Preserves original image bytes when no resize or format conversion is
needed.
- Enforces the shared 1 GiB encoded and decoded data-URL sanity limits.
- Replaces only an image that fails preparation, preserving sibling
content and tool-output metadata.
- Uses bounded placeholders distinguishing generic processing failures,
oversized images, and unsupported `low` detail.
- Prepares resumed and forked history before installing it as live
history without modifying persisted rollouts.
## Flag-Off Behavior
When `resize_all_images` is disabled:
- Existing local user-input and `view_image` processing remains
unchanged.
- Existing decoding and error behavior remains unchanged.
- Arbitrary tool-output images are not processed.
- HTTP(S) image URLs continue to be forwarded unchanged.
#### [git stack](https://github.com/magus/git-stack-cli)
- ✅ `1` https://github.com/openai/codex/pull/27245
- 👉 `2` https://github.com/openai/codex/pull/27247
- ⏳ `3` https://github.com/openai/codex/pull/27246
- ⏳ `4` https://github.com/openai/codex/pull/27266
## Why
When a realtime session is open without an active frontend-model
handoff, completed Codex assistant messages are currently dropped. That
prevents the frontend model from hearing orchestrator preambles and
final responses produced by typed turns or other non-handoff work, which
makes the two models present as disconnected personas.
Active handoffs already forward each completed assistant message,
including preambles. This change leaves those V1 and V2 paths intact and
fills only the no-active-handoff gap.
## What changed
- Send standalone V1 assistant messages through
`conversation.handoff.append` with a stable synthetic handoff ID
- Send standalone V2 assistant messages as normal `[BACKEND]`
`conversation.item.create` message items, then enqueue `response.create`
so the frontend model responds
- Preserve the existing active V1 and V2 transport and completion
behavior
- Continue excluding user messages from realtime mirroring
- Skip empty output and cap each complete context injection, including
its V2 prefix, at 1,000 tokens
- Add end-to-end coverage for both wire formats, V2 response creation,
preambles, final responses, and truncation
## Test plan
- CI
## Why
Compaction window identity is part of session history, not model-client
transport state. Persisting it with the compacted rollout item lets
resumed threads continue from the reconstructed window without keeping
mutable window state on `ModelClient`.
## What changed
- Added `window_id` to `CompactedItem` and stamp it when
`replace_compacted_history` installs compacted history.
- Moved auto-compact window id ownership into `AutoCompactWindow` /
`SessionState`; `ModelClient` now receives the request window id from
callers instead of storing it.
- Returned `window_id` from rollout reconstruction for resume.
Reconstruction uses the newest surviving compacted item's stored
`window_id` when present, and falls back to the legacy compacted-item
count when it is absent.
- Kept fork startup at the fresh default window id and updated direct
model-client tests to pass explicit test window ids.
## Validation
- `cargo check -p codex-core --tests`
## Summary
We originally addressed startup prewarming holding the read side of
`RwLock<McpConnectionManager>` by snapshotting tool-list state. Review
feedback identified the broader ownership problem: the outer
synchronization should only publish or retrieve the current manager,
while MCP operations rely on the manager's internal synchronization. A
follow-up preserved operation retirement with a separate gate, but
further review questioned whether that synchronization was actually
required and whether we could support latest-wins replacement instead.
This PR now stores the current MCP manager in `ArcSwap`. Each operation
uses `load_full()` to obtain an owned `Arc<McpConnectionManager>`, then
performs MCP I/O without retaining the publication mechanism. Refresh
cancels obsolete startup work, constructs a replacement, and atomically
publishes it. New operations see the latest manager, while operations
that already loaded the previous manager retain a valid handle. Refresh
happens at a turn boundary, so there should be no active user tool calls
to drain.
Git history supports dropping the outer `RwLock`. It was introduced in
`03ffe4d595` on November 17, 2025 for non-blocking MCP startup: the
session published an empty manager, startup initialized that same object
while holding the write lock, and readers waited for initialization.
`7cd2e84026` on February 19, 2026 removed that two-phase initialization
in favor of constructing a fresh manager and swapping it in, explicitly
noting that `Option` or `OnceCell` could replace the placeholder design.
Hot reload later reused the existing lock to publish a replacement, but
I found no indication that the lock was introduced to guarantee
in-flight tool calls finish before refresh or shutdown.
Terminal shutdown remains separate from refresh: it aborts startup
prewarming and active tasks before shutting down the current manager, so
tool calls may be interrupted and no model WebSocket work continues
after shutdown. Focused regression coverage exercises pending tool-list
cancellation, deferred refresh, and startup-prewarm shutdown.
## Why
Codex app-server latency traces do not granularly cover turn
orchestration, sampling-request preparation, and tool-loading work.
These spans help separate local coordination/setup costs from model
streaming and tool execution.
## What changed
- Add `run_turn.*` spans around sampling-request input preparation and
post-sampling state collection
- Add function-level trace spans around turn setup, hook execution,
compaction, prompt construction, and MCP tool exposure
- Add `built_tools.*` spans around plugin loading and discoverable-tool
loading
## Verification
Trigger Codex rollout and observe new spans are included
## Why
The realtime frontend model and the backing Codex thread should present
one coherent assistant. Raw typed messages, steers, and worker reports
belong to the orchestrator; the frontend model should receive the
orchestrator's user-facing result rather than a second copy of those
inputs.
Today normal `turn/start` input is automatically inserted into the
realtime conversation, while `turn/steer` is not. Besides creating
inconsistent context, this can make the frontend model react
independently before Codex has produced the response it should speak.
## What changed
- Remove automatic accepted-user-input mirroring into realtime
- Remove the mirror-only echo-suppression flag and dead V2 prefix helper
- Preserve explicit app-to-realtime text injection and FEM-to-Codex
delegation
- Replace the positive mirror tests and obsolete snapshots with a
negative routing regression test
## Test plan
- `cargo test -p codex-core
conversation_user_text_turn_is_not_sent_to_realtime`
- `cargo test -p codex-core
conversation_startup_context_is_truncated_and_sent_once_per_start`
- `cargo test -p codex-core inbound_handoff_request_starts_turn`
pakrym-oai