## Why
When `Feature::TokenBudget` is enabled, compaction should behave like
`new_context`: start a fresh context window with the standard injected
context, without asking the server to summarize old history and without
carrying prior user or assistant messages into the next model request.
This is still a compaction operation from the client lifecycle
perspective. Manual `/compact` and auto-compaction should keep the same
observable side effects that clients and hooks expect, including compact
hooks and `TurnItem::ContextCompaction`.
## What changed
- Added `compact_token_budget` to run token-budget manual and inline
auto-compaction through a shared compaction lifecycle.
- Split pending `new_context` requests from forced context-window
startup: `take_new_context_window_request()` consumes pending requests,
and `start_new_context_window()` installs a fresh context window.
- Routed token-budget manual `/compact` and inline auto-compaction to
install a fresh context window locally instead of calling server/local
summarization.
- Preserved compact lifecycle side effects for token-budget compaction
by running pre/post compact hooks and emitting `ContextCompaction` item
start/completion events.
- Updated token-budget tests to assert fresh window IDs, absence of
server-side compaction calls, dropped prior transcript messages/tool
output after reset, and compact hook/item lifecycle behavior.
## Testing
- `just test -p codex-core
token_budget_context_uses_new_window_after_compaction`
- `just test -p codex-core token_budget_compaction_runs_compact_hooks`
- `just test -p codex-core
token_budget_mid_turn_auto_compaction_resets_before_active_follow_up`
---------
Co-authored-by: pakrym-oai <pakrym@openai.com>
## Summary
- rename the rollout-budget exhaustion error from
`RolloutBudgetExceeded` to `SessionBudgetExceeded`
- expose the matching app-server v2 wire value as
`sessionBudgetExceeded`
- regenerate JSON/TypeScript schema fixtures and update the app-server
docs and focused tests
This is a naming-only follow-up to #29715 based on [Pavel's review
suggestion](https://github.com/openai/codex/pull/29715#discussion_r3463183480).
Runtime behavior is unchanged.
## Tests
- `just test -p codex-core rollout_budget`
- `just test -p codex-app-server-protocol`
- `just fmt`
- `just write-app-server-schema`
## Why
With `model_auto_compact_token_limit_scope = "body_after_prefix"`, the
persistent prefix should not count against the active body window.
`get_context_remaining` and the token-budget reminder should report the
same usable body-after-prefix window that auto-compaction uses, rather
than the total token count since the session began.
This is stacked on #29664 so the mechanical move from `turn.rs` is
isolated from the behavior fix.
## What
- Extends `ContextWindowTokenStatus` with `context_remaining_tokens`.
- Updates `get_context_remaining` to use the shared context-window
accounting.
- Adds integration coverage for body-after-prefix reminder timing and
`get_context_remaining` output.
## Testing
- `just test -p codex-core body_after_prefix_window`
- `just test -p codex-core auto_compact_body_after_prefix`
- `just fix -p codex-core`
## Why
This PR keeps the mechanical helper extraction separate from the
behavior change in #29665. The follow-up needs the token-window
accounting from `turn.rs` in another call path, but reviewing that is
much easier when the helper extraction is separate from the semantic
change.
## What
- Adds `session/context_window.rs` with `ContextWindowTokenStatus`.
- Moves the existing auto-compaction token-status calculation out of
`session/turn.rs`.
- Replaces the duplicated inline remaining-token calculation in
`turn.rs` with `tokens_until_compaction()`.
This PR is intended to be behavior-preserving. The
`get_context_remaining` behavior change is stacked separately in #29665.
## Testing
- `just test -p codex-core auto_compact_body_after_prefix`
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/29664).
* #29665
* __->__ #29664
## Why
The app-server and exec-server expose separate JSON-RPC APIs, but
exec-server currently sources its serialized protocol and envelope types
through app-server-oriented code. Giving each API an explicit owner
makes the crate boundary legible without introducing shared generic
envelopes.
## What changed
- Added `codex-exec-server-protocol` to own exec DTOs, process IDs, and
JSON-RPC envelopes.
- Updated exec-server clients, transports, handlers, and tests to use
the new crate.
- Exposed app-server's existing JSON-RPC types through a public `rpc`
module while retaining root re-exports.
- Preserved existing wire shapes, including exec `PathUri` behavior.
## Stack
This is PR 1 of 6. Next: [PR
#29721](https://github.com/openai/codex/pull/29721), which moves auth
mode below the app wire boundary.
## Validation
- Exec-server protocol and server coverage passed in the focused
protocol test runs.
- App-server protocol schema fixtures passed.
## Why
After #28918, selected skill roots are `PathUri`, but the executor skill
provider still converts them to the app-server host's `AbsolutePathBuf`.
A foreign Windows root therefore cannot be discovered by a Unix host,
and the inverse has the same problem.
This PR keeps executor skill discovery and reads on the filesystem that
owns the selected root while reusing the existing skill rules.
## What changed
- Generalize the existing skill traversal to operate on `PathUri`
through `ExecutorFileSystem`, preserving its depth, directory, symlink,
and sibling-metadata concurrency behavior.
- Add a small environment skill loader that reuses the shared discovery,
frontmatter validation, dependency parsing, product policy, and
prompt-visibility rules.
- Keep the environment id and entrypoint `PathUri` in the skill catalog,
then route `skills.read` back through the same environment filesystem.
- Preserve the executor's path convention when deriving catalog handles,
including literal backslashes in POSIX filenames.
- Resolve plugin namespaces from nearby manifests through URI-native
filesystem reads.
- Cover foreign Windows roots, executor-owned reads, namespaces,
metadata, policy, and path identity.
```text
selected root (PathUri)
|
v
shared discovery over ExecutorFileSystem
|
v
environment-bound catalog entry --skills.read--> same ExecutorFileSystem
```
No second filesystem abstraction or duplicate traversal implementation
is introduced.
## Stack
1. #29614 — add lexical `PathUri` containment.
2. #29620 — share URI-native manifest path resolution.
3. #28918 — keep selected plugin roots and resources URI-native.
4. **This PR** — load executor skills without host path conversion.
5. #29628 — resolve executor MCP working directories without host path
conversion.
Remove this unused API. This API is insidious in that it implies that
alive state should be determinable from the caller, and implies that a
preflight should indicate routing. Lets drop this, and handle errors
correctly from a failed session in the future.
## Summary
- surface shared rollout-budget exhaustion as
`CodexErr::RolloutBudgetExceeded` instead of a generic interrupted turn
- map it through the existing `CodexErrorInfo` and app-server v2
`codexErrorInfo` path
- keep local compaction from retrying after the shared rollout budget is
exhausted
This gives app-server clients a stable `rolloutBudgetExceeded` error
they can classify without guessing from `status="interrupted"`.
## Tests
- `just test -p codex-core rollout_budget`
## Summary
- add validated protocol-version, capability, and session identifier
types
- define explicit `ClientToHost` and `HostToClient` JSON envelopes for
connection negotiation and session open/close acknowledgements
- reject invalid states and unknown fields during decoding, with
explicit wire-format and round-trip coverage
## Why
This establishes the transport-neutral encoding shape needed to build
and test the new code-mode host incrementally. Cell, tool callback, and
failure-domain messages are intentionally deferred until their actors
and behavior tests establish the required semantics.
This is additive protocol scaffolding and does not change the current
production code-mode implementation.
## Validation
## Why
Selected capability roots belong to the executor filesystem, not the
app-server host. Converting their path strings into the host's native
`Path` breaks whenever the two machines use different path conventions,
such as a Windows executor behind a Unix app-server.
This PR establishes `PathUri` as the selected-plugin boundary so the
executor remains authoritative for its paths.
## What changed
- Require `selectedCapabilityRoots[].location.path` to be a canonical
`file:` URI and deserialize it directly as `PathUri`; native path
strings are rejected.
- Update the app-server schema, generated TypeScript, examples, and
request coverage for the URI contract.
- Keep selected roots, resolved plugin locations, manifest paths, and
manifest resources as `PathUri`.
- Inspect and read plugin roots and manifests only through the selected
environment's `ExecutorFileSystem`.
- Parse executor manifests with the shared URI-native parser from #29620
instead of projecting them onto the host filesystem.
- Enforce resource containment lexically and preserve the root URI's
POSIX or Windows path convention.
- Cover foreign Windows plugin roots and URI-native manifest resources.
```text
thread/start
selectedCapabilityRoots[].location.path = "file:///C:/plugins/demo"
| PathUri
v
ExecutorFileSystem
|
+--> plugin.json
+--> manifest resources
```
This PR stops at the shared selected-plugin representation. The next two
PRs remove the remaining host-path projections in the skill and MCP
consumers.
## Stack
1. #29614 — add lexical `PathUri` containment.
2. #29620 — share URI-native manifest path resolution.
3. **This PR** — keep selected plugin roots and resources URI-native.
4. #29626 — load executor skills without host path conversion.
5. #29628 — resolve executor MCP working directories without host path
conversion.
## Why
PR #29494 made context-window IDs visible to the model by wrapping the
token-budget window payload in `<context_window>`, but rollout JSONL
consumers still could not see the initial window identity by tailing the
session file. Compacted rollout items carry window IDs only after
compaction has happened, so a session with no compaction had no durable
JSONL record for window 0.
This change gives tailing consumers a stable initial-window record at
session creation time.
## What Changed
- Added `session_meta.context_window.window_id` for the initial
context-window identity.
- `CreateThreadParams` now requires `initial_window_id: String`, so
thread-store callers cannot accidentally create new threads without
window-0 metadata.
- Live thread creation derives the persisted initial window ID from the
same `AutoCompactWindowIds` used to initialize `SessionState`, keeping
runtime state and JSONL metadata aligned.
- Rollout reconstruction uses `session_meta.context_window.window_id` as
the initial-window fallback and derives `window_number = 0`,
`first_window_id = window_id`, and `previous_window_id = None`
internally.
- Fork reconstruction intentionally uses the same rollout reconstruction
path; consumers that need to distinguish copied initial-window metadata
can use the rollout `thread_id`.
- Legacy compactions without `window_number` still use compaction-count
fallback accounting instead of being reset to window 0 by the
initial-window fallback.
- Compacted rollout metadata still takes precedence once compaction
records exist, preserving the richer chain fields there.
## JSONL Shape
Real rollout JSONL is one object per line. This example is expanded for
readability, but shows the new initial `session_meta.context_window`
record followed by the existing compacted rollout item shape that also
carries window IDs:
```jsonl
{
"timestamp": "2026-06-22T12:00:00.000Z",
"type": "session_meta",
"payload": {
"session_id": "<THREAD_ID>",
"id": "<THREAD_ID>",
"timestamp": "2026-06-22T12:00:00.000Z",
"cwd": "/repo",
"originator": "codex",
"cli_version": "0.0.0",
"source": "cli",
"model_provider": "<MODEL_PROVIDER>",
"context_window": {
"window_id": "<INITIAL_WINDOW_ID>"
}
}
}
...
{
"timestamp": "2026-06-22T12:34:56.000Z",
"type": "compacted",
"payload": {
"message": "<COMPACTION_SUMMARY>",
"replacement_history": [
"..."
],
"window_number": 1,
"first_window_id": "<INITIAL_WINDOW_ID>",
"previous_window_id": "<INITIAL_WINDOW_ID>",
"window_id": "<NEXT_WINDOW_ID>"
}
}
```
The nested `context_window` object is intentional: it gives rollout
consumers a stable namespace for context-window metadata while only
writing the non-derivable initial `window_id`. For the initial window,
`window_number`, `first_window_id`, and `previous_window_id` are derived
internally instead of being written to the rollout.
## Verification
- `just test -p codex-protocol`
- `just test -p codex-rollout
recorder_materializes_on_flush_with_pending_items`
- `just test -p codex-core reconstruct_history`
- `just test -p codex-core
record_initial_history_reconstructs_forked_transcript`
- `just test -p codex-thread-store`
- `just test -p codex-state`
- `just test -p codex-app-server
thread_read_returns_summary_without_turns`
- `just test -p codex-rollout persistence_metrics`
## Why
I'd originally added `PathUri` legacy path deserialization thinking we'd
want it for having `PathUri` in public app-server APIs. Since then we've
added `LegacyAppPathString` to handle the messy conversions that we need
for backcompat. It's confusing for `PathUri` to support deserializing
legacy paths when we don't yet want to actually expose app-server
callers or rollout storage to the new URI format.
Stacked on top of #29472 to avoid breaking compatibility in case those
types ended up stored somewhere for someone.
## What changed
- Parse deserialized `PathUri` values exclusively as valid `file:` URIs.
- Replace legacy acceptance coverage with rejection coverage for
top-level filesystem paths and sandbox working directories.
- Serialize CWDs in hand-built exec-server process requests as `PathUri`
values.
## Why
Use a clearer name for what happens when this helper sets up a test
environment.
## What
- Rename the builder and its harness wrapper to use `auto_env` instead
of `remote_env` because the helper will set up a local environment if
configured by the build system.
Record the initial AutoCompactWindowIds window_id in session_meta.context_window so JSONL tailers can observe the first context window before any compaction item exists. Thread creation now requires an initial_window_id string, while rollout JSONL keeps that value under the context_window namespace without writing derived chain fields for the initial window.
Rollout reconstruction derives window 0 state from that initial_window_id when no compaction window metadata exists. Forks intentionally use the same reconstruction path; consumers that need to distinguish copied initial-window metadata can use thread_id. Legacy compactions without window_number continue to use compaction-count fallback accounting.
Verification:
- just test -p codex-protocol
- just test -p codex-rollout recorder_materializes_on_flush_with_pending_items
- just test -p codex-core reconstruct_history_restores_initial_window_from_session_meta
- just test -p codex-core reconstruct_history_prefers_compacted_window_over_session_meta
- just test -p codex-core reconstruct_history_preserves_legacy_compaction_count_with_session_meta_window
- just test -p codex-core reconstruct_history
- just test -p codex-core record_initial_history_reconstructs_forked_transcript
- just test -p codex-thread-store
- just test -p codex-state
- just test -p codex-app-server thread_read_returns_summary_without_turns
- just test -p codex-rollout persistence_metrics
- just fix -p codex-protocol -p codex-rollout -p codex-thread-store -p codex-core -p codex-app-server
- just fix -p codex-core -p codex-rollout
- just fix -p codex-core
## Why
Core tests should branch on the executor's operating system, not on
runner details such as Docker or Wine. This keeps platform behavior
stable as new test backends are added and reserves Wine-specific skips
for actual runner debt.
## What
- Add `TestTargetOs` and target/host-aware skip helpers while keeping
`TestEnvironment` internal.
- Replace topology enum access with remote predicates and a narrow
Docker accessor.
- Migrate OS-semantic Wine skips, preserve runner-specific gaps, and
document the skip taxonomy.
## Validation
- `just test -p core_test_support`
- `just test -p codex-core
remote_test_env_can_connect_and_use_filesystem`
- `bazel test //codex-rs/core:core-all-wine-exec-test
--test_output=errors` reached test execution; unrelated existing
view-image, path, and timing failures remain.
- `just test -p codex-core` and `just test` reached broad test
execution; this checkout has unrelated helper, sandbox, and timing
failures.
Record the initial AutoCompactWindowIds window_id in session_meta.context_window so JSONL tailers can observe the first context window before any compaction item exists. Thread creation now requires an initial_window_id string, while rollout JSONL keeps that value under the context_window namespace without writing derived chain fields for the initial window.
Rollout reconstruction derives window 0 state from that initial_window_id when no compaction window metadata exists. Forks intentionally use the same reconstruction path; consumers that need to distinguish copied initial-window metadata can use thread_id. Legacy compactions without window_number continue to use compaction-count fallback accounting.
Verification:
- just test -p codex-protocol
- just test -p codex-rollout recorder_materializes_on_flush_with_pending_items
- just test -p codex-core reconstruct_history_restores_initial_window_from_session_meta
- just test -p codex-core reconstruct_history_prefers_compacted_window_over_session_meta
- just test -p codex-core reconstruct_history_preserves_legacy_compaction_count_with_session_meta_window
- just test -p codex-core reconstruct_history
- just test -p codex-core record_initial_history_reconstructs_forked_transcript
- just test -p codex-thread-store
- just test -p codex-state
- just test -p codex-app-server thread_read_returns_summary_without_turns
- just test -p codex-rollout persistence_metrics
- just fix -p codex-protocol -p codex-rollout -p codex-thread-store -p codex-core -p codex-app-server
- just fix -p codex-core -p codex-rollout
- just fix -p codex-core
Record the initial AutoCompactWindowIds window_id in session_meta.context_window so JSONL tailers can observe the first context window before any compaction item exists. Thread creation now requires an initial_window_id string, while rollout JSONL keeps that value under the context_window namespace without writing derived chain fields for the initial window.
Rollout reconstruction derives window 0 state from that initial_window_id when no compaction window metadata exists. Forks intentionally use the same reconstruction path; consumers that need to distinguish copied initial-window metadata can use thread_id. Legacy compactions without window_number continue to use compaction-count fallback accounting.
Verification:
- just test -p codex-protocol
- just test -p codex-rollout recorder_materializes_on_flush_with_pending_items
- just test -p codex-core reconstruct_history_restores_initial_window_from_session_meta
- just test -p codex-core reconstruct_history_prefers_compacted_window_over_session_meta
- just test -p codex-core reconstruct_history_preserves_legacy_compaction_count_with_session_meta_window
- just test -p codex-core reconstruct_history
- just test -p codex-core record_initial_history_reconstructs_forked_transcript
- just test -p codex-thread-store
- just test -p codex-state
- just test -p codex-app-server thread_read_returns_summary_without_turns
- just test -p codex-rollout persistence_metrics
- just fix -p codex-protocol -p codex-rollout -p codex-thread-store -p codex-core -p codex-app-server
- just fix -p codex-core -p codex-rollout
- just fix -p codex-core
Mechanical rename of CodeModeService => InProcessCodeModeSession
This already implements a CodeModeSession as its prime interface to
Core. The name was vestigial _and_ confusing af when embedded inside
core::tools::code_mode::CodeModeService
Record the initial AutoCompactWindowIds window_id in session_meta.context_window so JSONL tailers can observe the first context window before any compaction item exists. Thread creation now requires an initial_window_id string, while rollout JSONL keeps that value under the context_window namespace without writing derived chain fields for the initial window.
Rollout reconstruction derives window 0 state from that initial_window_id when no compaction window metadata exists. Forks intentionally use the same reconstruction path; consumers that need to distinguish copied initial-window metadata can use thread_id. Legacy compactions without window_number continue to use compaction-count fallback accounting.
Verification:
- just test -p codex-protocol
- just test -p codex-rollout recorder_materializes_on_flush_with_pending_items
- just test -p codex-core reconstruct_history_restores_initial_window_from_session_meta
- just test -p codex-core reconstruct_history_prefers_compacted_window_over_session_meta
- just test -p codex-core reconstruct_history_preserves_legacy_compaction_count_with_session_meta_window
- just test -p codex-core reconstruct_history
- just test -p codex-core record_initial_history_reconstructs_forked_transcript
- just test -p codex-thread-store
- just test -p codex-state
- just test -p codex-app-server thread_read_returns_summary_without_turns
- just test -p codex-rollout persistence_metrics
- just fix -p codex-protocol -p codex-rollout -p codex-thread-store -p codex-core -p codex-app-server
- just fix -p codex-core -p codex-rollout
- just fix -p codex-core
## Description
Rename the experimental app-server item pagination API from
`thread/turns/items/list` to `thread/items/list` and make `turnId`
optional. Clients can now page persisted items across a thread, or still
filter to one turn when needed.
## What changed
- Rename the request/response protocol types and JSON-RPC method to
`ThreadItemsList*` / `thread/items/list`.
- Pass optional `turnId` through to `ThreadStore::list_items`.
- Update app-server docs and focused protocol/app-server tests.
## Validation
- `just test -p codex-app-server-protocol thread_items_list_round_trips`
- `just test -p codex-app-server thread_items_list_returns_unsupported`
Michael Bolin