## Why
A process host should be discarded and rebuilt after critical actor or
V8 failure, while the existing in-process production path must keep its
current cell-error semantics. This change establishes that failure
boundary without adding the host process or remote client.
## What changed
- add optional task-failure supervision to the transport-neutral
code-mode session runtime
- report Tokio cell-actor failures and V8 runtime-thread panics to a
host-provided fail-stop handler
- preserve the existing handler-less in-process behavior
- make host-owned cell ID allocation fail before numeric wraparound
## Follow-up
The V8 panic signal surfaced here should also be consumed by the
`InProcessCodeModeSession` manager in a future change so it can fail the
affected cell. This PR intentionally leaves the handler-less in-process
behavior unchanged while putting the required panic tracking in place.
## Stack
This is **2 of 4** in the process-owned code-mode session stack.
- #30108 is merged into `main`
- The next PR targets this branch
## Validation
- `just test -p codex-code-mode` — 53 passed
- `just argument-comment-lint -p codex-code-mode`
- `just fix -p codex-code-mode`
## Summary
- recognize `codex_work_web` and `codex_work_mobile` as supported
`thread/start.serviceName` values
- use the recognized value as the thread-scoped originator, with the
same persistence and request propagation added for `codex_work_desktop`
- cover precedence over persisted and inherited originators
This is the Codex consumer for the service names introduced by
[openai/openai#1073178](https://github.com/openai/openai/pull/1073178).
## Rollout / Compatibility
The producer is ChatGPT's app-server integration in
openai/openai#1073178. This PR is the Codex app-server consumer that
converts those service names into the outgoing per-thread `originator`.
Until this change is deployed, the new service names are ignored and
Codex continues using its fallback originator. Deploy this mapper and
the matching codex-backend compatibility change in
[openai/openai#1073594](https://github.com/openai/openai/pull/1073594)
while the existing Flora egress overwrite remains in place. Remove that
overwrite in
[openai/openai#1073197](https://github.com/openai/openai/pull/1073197)
only after both consumers are deployed.
## Validation
- `just test -p codex-core
effective_originator_prefers_thread_scoped_sources_before_env_originator`
- `just fix -p codex-core`
- `just fmt`
## Summary
- distinguish expired, non-refreshable stored MCP OAuth credentials from
first-time missing credentials
- carry a typed `failureReason: "reauthenticationRequired"` on the
existing `mcpServer/startupStatus/updated` notification only when user
action is required
- keep the public MCP auth-status API unchanged and regenerate the
app-server protocol schemas and documentation
## Why
An MCP server with an expired access token and no usable refresh token
currently fails startup without giving clients a reliable, typed
recovery signal.
The existing startup-status notification is the natural place to carry
this state. Its nullable `failureReason` keeps the recovery reason
attached to the failed startup transition without adding a one-off
notification. Internally, Codex distinguishes first-time login from
reauthentication and emits the reason only when the startup error itself
requires authentication.
## User impact
App clients can prompt an existing user to reconnect an MCP server when
automatic recovery is impossible by handling a failed
`mcpServer/startupStatus/updated` notification whose `failureReason` is
`reauthenticationRequired`. Starting, ready, cancelled, unrelated
failures, and first-time setup carry no reauthentication reason.
## Companion app PR
- openai/openai#1069582
## Validation
- `just test -p codex-app-server-protocol` — 248 passed; schema fixture
tests passed
- `cargo check -p codex-app-server -p codex-tui`
- `just test -p codex-rmcp-client -p codex-mcp` — 184 passed, 2 skipped
- `just test -p codex-protocol -p codex-app-server-protocol -p
codex-mcp` — 579 passed
- `just write-app-server-schema`
- `just fmt`
## Why
The TUI uses `thread/rollback` internally for user-facing flows such as
prompt cancellation/backtracking. After `thread/rollback` was marked
deprecated, those internal calls started surfacing `deprecationNotice`
messages in the TUI, even though the user did not explicitly call the
deprecated app-server API.
The endpoint should remain deprecated for external app-server clients,
but the built-in `codex-tui` client should not show this
implementation-detail warning during normal interaction.
## What changed
- Pass the initialized app-server client name into the `thread/rollback`
request processor.
- Suppress the `thread/rollback` deprecation notice only for
`codex-tui`.
- Preserve the existing `deprecationNotice` behavior for non-TUI
clients.
- Add regression coverage for the `codex-tui` suppression path.
## How to Test
1. Start Codex TUI from this branch.
2. Type text into the composer and press `Esc` to cancel/backtrack.
3. Confirm the TUI restores/cancels the prompt without showing
`thread/rollback is deprecated and will be removed soon`.
4. Also verify an external app-server client that calls
`thread/rollback` still receives `deprecationNotice`.
Targeted tests:
- `just test -p codex-app-server thread_rollback`
- `just argument-comment-lint`
## Why
#29856 already owns the durable thread intent and exact environment
binding. This PR adds only the small missing extension boundary: an
extension can contribute one named World State section, while core still
owns persistence, diffing, and model-visible fragment types.
This lets skills stay in the skills extension instead of moving their
runtime into core.
## Shape
```text
extension-owned state
|
| contribute section id + JSON snapshot + renderer
v
core World State
|
| compare with the previous snapshot
v
no message, or one incremental model-visible update
```
The extension API is deliberately small:
```rust
fn contribute_world_state(...) -> Vec<WorldStateSectionContribution>
```
Core adapts the rendered result to `ContextualUserFragment`, records the
snapshot, and keeps the existing compaction/resume behavior.
## What changes
- Adds extension-owned World State section contributions.
- Calls those contributors from the existing per-step World State
builder.
- Restores durable selected capability roots into extension thread state
on resume.
- Keeps the actual model-context fragment and rollout machinery in core.
## What does not change
- No skill or MCP implementation moves out of its extension.
- No new file watcher, generation, or RPC.
- No generic migration of existing World State sections.
- No change to the stable environment-ID assumption from #29856.
## Example
```text
step 1 snapshot: skills = []
step 2 snapshot: skills = [executor-demo:deploy]
core asks the skills extension to render only that change.
```
## Stack
1. **This PR:** let extensions contribute World State sections.
2. Project executor skills through the skills extension.
3. Pin one MCP runtime to each model step.
4. Project selected MCP/app/connector metadata by environment
availability.
5. One end-to-end integration scenario.
## Summary
This PR extends the existing managed `mcp_servers` identity requirement
so that one name-qualified rule can use either:
- the released exact command or URL identity;
- an exact stdio executable with an exact-length, ordered argument
matcher list; or
- a direct MCP URL matcher.
Matcher-based rules stay under the released `identity` key and use the
same `McpServerRequirement` abstraction and `mcp_servers.<server_name>`
namespace.
## Behavior
Policy activation and name qualification are unchanged:
- If `mcp_servers` is absent, ordinary configured MCP servers remain
unrestricted.
- If `mcp_servers` is present, a server needs a matching same-name
requirement.
- `mcp_servers = {}` continues to deny every configured MCP server.
- Existing exact identity requirements keep their released semantics.
Plugin-bundled MCP servers use the same requirement shapes under
`plugins.<plugin_name>.mcp_servers.<server_name>`. Top-level non-empty
rules continue to govern only ordinary configured servers; plugin rules
remain explicitly plugin-scoped. The existing globally empty
`mcp_servers = {}` plugin kill switch is preserved.
Requirements layers continue to use the existing regular TOML merge
behavior. Atomic replacement of named MCP requirements is intentionally
out of scope here and is tracked independently in #30118.
## Requirement contract
The released exact identity contract remains valid:
```toml
[mcp_servers.docs.identity]
command = "codex-mcp"
[mcp_servers.remote.identity]
url = "https://example.com/mcp"
```
Command identities continue to check only `command`; they do not inspect
arguments, `cwd`, `env`, or `env_vars`.
A command matcher uses an exact executable plus an exact-length, ordered
argument list. Each argument position supports `exact`, `prefix`, or
full-value `regex` matching:
```toml
[mcp_servers.internal_mcp_proxy.identity]
command = { executable = "company-cli", args = [
{ match = "exact", value = "mcp" },
{ match = "exact", value = "proxy" },
{ match = "exact", value = "--server" },
{ match = "regex", expression = '^https://[A-Za-z0-9-]+\.mcp\.internal\.example\.com(?::443)?(?:/.*)?$' },
] }
```
Direct streamable HTTP MCP definitions can use the same value matcher
types through `identity.url`:
```toml
[mcp_servers.internal_http.identity]
url = {
match = "regex",
expression = '^https://[A-Za-z0-9-]+\.mcp\.internal\.example\.com(?:/.*)?$',
}
```
Plugin-bundled MCP matchers use the same contract inside the
plugin-qualified allowlist:
```toml
[plugins."sample@test".mcp_servers.internal_mcp_proxy.identity]
command = { executable = "company-cli", args = [
{ match = "exact", value = "mcp" },
{ match = "exact", value = "proxy" },
] }
```
Regexes are validated while managed requirements are loaded, and regex
matching must cover the complete value. Command matchers constrain only
the executable and arguments.
## Why
Enterprise administrators need to allow MCP servers by executable and
positional-argument shape, including fixed arguments plus constrained
values such as internal MCP URLs passed to a proxy.
## Validation
- `just fmt`
- `git diff --check`
- `just test -p codex-config` (198 passed)
- `just test -p codex-core mcp_servers_by_matchers --lib` (2 passed)
## Why
Once #30114 publishes zsh independently, regular Rust releases should
reuse that protected, versioned artifact set instead of rebuilding
identical zsh binaries for every Codex version. Keeping the zsh release
tag explicit in the workflow also makes future artifact upgrades
deliberate and easy to review.
This PR assumes the first standalone artifact release will be published
as `codex-zsh-v0.1.0` before this change lands.
## What changed
- Added `CODEX_ZSH_RELEASE_TAG` near the top of
`.github/workflows/rust-release.yml`, initially pinned to
`codex-zsh-v0.1.0`.
- Download the standalone release’s generated `codex-zsh` DotSlash
manifest before assembling Linux and macOS Codex packages.
- Added a `--zsh-manifest` package-builder override so release packaging
fetches the matching target archive and verifies the size and SHA-256
digest recorded in that manifest.
- Removed the reusable zsh build job from regular Rust releases.
- Stopped copying zsh archives into each Rust release and stopped
regenerating a zsh DotSlash manifest there.
Windows packaging remains unchanged because the patched zsh resource is
only shipped for supported Unix targets.
## Testing
- Added package-helper coverage that supplies a standalone manifest
override and verifies the extracted zsh bytes.
- Ran the `scripts/codex_package` unit test suite.
- Validated `.github/scripts/build-codex-package-archive.sh` with `bash
-n`.
## Why
The patched zsh artifacts rarely change, but
`.github/workflows/rust-release-zsh.yml` currently runs as part of every
Rust release. Rebuilding the same four binaries for each Codex version
wastes release capacity and ties an independently versioned runtime
dependency to the main release cadence.
This establishes the producer side of a build-once flow. The existing
Rust release workflow remains unchanged until the first standalone
artifact release has been published and the checked-in DotSlash
manifests can be updated with its URLs and checksums.
## What changed
- Run the zsh release workflow for protected `codex-zsh-vX.Y.Z` tags
instead of as a reusable workflow.
- Validate the semantic release tag before starting the platform builds.
- Publish the four zsh archives to a GitHub prerelease so the release
never becomes the repository latest release.
- Publish the generated `codex-zsh` DotSlash manifest alongside the
archives.
- Document how to publish the next artifact version after changing the
pinned zsh commit or patch.
## Tag protection
An active repository tag ruleset named `codex-zsh-v*.*.*` targets
`refs/tags/codex-zsh-v*.*.*`. It restricts tag creation, updates,
deletion, and non-fast-forward changes; requires linear history; and
limits bypass to the configured repository role.
This was verified with:
```shell
gh api repos/openai/codex/rulesets/18140982
```
The response reported `"enforcement":"active"`, the expected tag
condition, and the `creation`, `update`, `deletion`, `non_fast_forward`,
and `required_linear_history` rules.
## Rollout
After this lands, publish the first `codex-zsh-vX.Y.Z` release. A
follow-up can then update the checked-in DotSlash manifests and remove
the zsh rebuild from `.github/workflows/rust-release.yml`.
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/30114).
* #30116
* __->__ #30114
## Description
This makes Codex Apps tool reads use a shared in-memory snapshot instead
of rereading the disk cache every time `list_all_tools()` runs. Disk
still seeds the cache on startup and gets updated after successful
fetches, but it is no longer the live read path.
The core change is that `McpManager` now owns a process-scoped
`CodexAppsToolsCache`. Codex threads in the same app-server process now
share this Codex Apps in-memory tools snapshot. The snapshot is keyed by
the Codex home plus the Codex Apps identity: the active Codex auth
user/workspace and the effective Codex Apps MCP source config.
There's already code to hard-refresh the cache, so we respect it in this
PR.
## Local benchmark
I ran a local steady-state microbenchmark of the exact repeated Codex
Apps cached-tools read this PR removes, using the same real local cache
payload in both trees: `3,678,138` bytes and `381` tools. The cache file
was already warm in the OS page cache, so this measures same-process
reread/deserialization work rather than cold-disk latency or full turn
latency. Each run is 25 iterations (mimicking a turn that makes 25
inference calls).
| Version | Run 1 | Run 2 | Avg |
|---|---:|---:|---:|
| `origin/main` disk read + JSON deserialize + `filter_tools` | `50.755
ms` | `52.894 ms` | `51.825 ms` |
| This branch in-memory `current_tools` + `filter_tools` | `0.740 ms` |
`0.778 ms` | `0.759 ms` |
That removes about `51 ms` from each repeated Codex Apps cached-tools
read on this machine, roughly `68x` faster for that subpath. It is
useful evidence for the hot path this PR changes, but not a claim that
every production turn gets `51 ms` faster; end-to-end impact also
depends on the rest of `list_all_tools()` and tool-payload construction.
This is on my M2 Max macbook, so with a slower disk this would be much
worse (and indeed we did see this really blew up turn runtime with a
slow disk).
## Summary
- make the external app-server time provider establish sleep deadlines
using `currentTime/read`
- poll the external clock once per second and complete `clock.sleep`
when the deadline is reached
- keep the system-clock timer and existing steer/agent-message
interruption behavior unchanged
## Why
This lets training control `clock.sleep` through its existing external
simulated clock without adding separate sleep/wake protocol methods.
## Testing
- `just fmt`
- `just test -p codex-app-server
external_sleep_polls_current_time_and_emits_items`
## Summary
- Record bounded duration and outcome metrics for remote environment
registration and Noise rendezvous connection attempts.
- Count reconnects by bounded reason: disconnect, connection failure, or
rejected registration.
- Trace registration at the owning client boundary without exporting raw
environment or registration identifiers.
- Replace the stale pre-Noise WebSocket observability design with the
current remote transport model.
## Stack
Review and land this stack in order:
1. #27466 — trace exec-server JSON-RPC requests
2. #27467 — record bounded connection, request, and process lifecycle
metrics
3. #27470 — observe remote registration and Noise rendezvous lifecycle
**(this PR)**
## Validation
- `just test -p codex-exec-server --lib` (149 passed)
- `just test -p codex-cli --test exec_server` (4 passed)
- `just argument-comment-lint`
- `just bazel-lock-check`
- `just fix -p codex-exec-server -p codex-cli`
- `just fmt`
## Summary
- add an `EncodedFrame` type so IPC payloads are serialized and
size-checked before entering bounded queues
- add the V1 `operation/cancel` client-to-host message
- pin the new wire shape with protocol tests
## Why
The process-owned code-mode host needs bounded, pre-encoded outbound
messages and a best-effort cancellation signal. Keeping these wire
primitives in a protocol-only change lets their compatibility contract
be reviewed independently from either endpoint.
## Stack
This is **1 of 4** in the process-owned code-mode session stack. The
next PR targets this branch.
## Validation
- `just test -p codex-code-mode-protocol` — 22 passed
- `just fix -p codex-code-mode-protocol`
- `just fmt`
## Summary
- track user-like input and tool-output boundaries in current-time
reminder state
- gate reminder injection when delivery_mode is
after_user_or_tool_output
- preserve interval debounce and forced reminders after context-window
changes
## Why
Training can request reminders only after user or tool-output items
while keeping the existing canonical pre-inference history-injection
path.
## Validation
- just test -p codex-core
current_time_reminders_can_follow_only_user_or_tool_outputs
- just test -p codex-core
current_time_reminders_follow_time_interval_and_persist_in_history
- just test -p codex-core
current_time_reminder_is_refreshed_after_compaction
- just fix -p codex-core
## Summary
- retry ERS `409 environment_offline` responses inside the existing
exec-server recovery loop
- keep all other registry conflicts terminal
- add focused coverage for both cases
## Root cause
When an exec server disconnects and reconnects, the client already
starts recovery and calls ERS `/connect`. During the transient executor
presence gap, ERS can return `409 environment_offline`. The retry
classifier treated every 409 as terminal, so the first response aborted
the existing 25-second recovery window before the executor came back
online. That then caused active processes to be marked lost.
This change classifies only the structured `environment_offline`
conflict as retryable. Recovery continues with the existing bounded
deadline, exponential backoff, and jitter.
## Validation
- `just test -p codex-exec-server client::recovery::tests` — 4 passed
- `just fix -p codex-exec-server` — passed
- `just fmt` — passed
- Full `just test -p codex-exec-server` reached unrelated macOS
filesystem-sandbox integration failures because nested
`/usr/bin/sandbox-exec` is denied in this environment (`sandbox_apply:
Operation not permitted`).
## tl;dr
Inject a `CODEX_PERMISSION_PROFILE` environment variable with the name
of the current permission profile when invoking a shell tool.
## Why
Shell tool owners may need to launch nested commands under the same
named permission profile, including through `codex sandbox -P PROFILE
--include-managed-config`. Until now, child processes could observe
sandbox and network metadata but could not identify the active named
permission profile.
The `--include-managed-config` flag is essential when a helper
reconstructs the sandbox from a profile name: it ensures the nested
sandbox also loads managed enterprise requirements. Without it, using
the inherited profile could unintentionally create a sandbox that does
not enforce the organization's managed restrictions.
The new environment value is intentionally informational and **must not
be treated as trusted input**. Any process in the ancestry can overwrite
an environment variable, so a consumer that passes this value to `codex
sandbox -P` must first validate it against the profiles that helper is
authorized to use.
## Example Use Case
Suppose an organization provides a trusted `remote-bash` wrapper that
lets Codex run a command on an approved build host. The local shell
command uses the named `:workspace` permission profile:
```toml
default_permissions = ":workspace"
```
The command exposed to the model is a small zsh wrapper. It deliberately
delegates with `exec`, preserving the original arguments and process
environment:
```zsh
#!/usr/bin/env zsh
exec /opt/codex-tools/remote_bash.py "$@"
```
The model invokes the public wrapper, not its Python implementation:
```sh
/opt/codex-tools/remote-bash \
--host builder.example.com \
-- printf '%s' 'hello world'
```
Only the inner implementation is authorized to escape the local sandbox:
```starlark
prefix_rule(
pattern=["/opt/codex-tools/remote_bash.py"],
decision="allow",
)
```
With zsh-fork, execution begins with `remote-bash` inside the
`:workspace` sandbox. When the wrapper calls `exec`, the exact prefix
rule matches `remote_bash.py`, so that inner script is restarted
unsandboxed. The escalated process inherits:
```text
CODEX_PERMISSION_PROFILE=:workspace
```
Inheritance does not make the value trustworthy. `remote_bash.py`
independently allowlists both the remote host and the permission profile
before using either value. In particular, a forged value such as
`:danger-full-access` is rejected before it can reach `codex sandbox
-P`:
```python
import argparse
import os
import shlex
import sys
ALLOWED_HOSTS = {"builder.example.com"}
ALLOWED_PROFILES = {":workspace"}
parser = argparse.ArgumentParser()
parser.add_argument("--host", required=True)
separator = sys.argv.index("--")
args = parser.parse_args(sys.argv[1:separator])
command = sys.argv[separator + 1:]
if args.host not in ALLOWED_HOSTS:
parser.error("host is not allowlisted")
if not command:
parser.error("the remote command must not be empty")
profile = os.environ.get("CODEX_PERMISSION_PROFILE")
if not profile:
raise SystemExit("CODEX_PERMISSION_PROFILE must not be empty")
if profile not in ALLOWED_PROFILES:
raise SystemExit("CODEX_PERMISSION_PROFILE is not allowlisted")
remote_command = shlex.join(command)
sandbox_command = shlex.join([
"codex", "sandbox", "-P", profile,
"--include-managed-config", "--",
"bash", "-lc", remote_command,
])
print(shlex.join(["ssh", args.host, sandbox_command]))
```
This builds each command layer as an argument vector and uses
`shlex.join()` at the boundary, rather than interpolating untrusted
shell text. After validation and parsing, the nested command has this
structure:
```text
ssh argv:
["ssh", "builder.example.com", SANDBOX_COMMAND]
SANDBOX_COMMAND argv:
["codex", "sandbox", "-P", ":workspace",
"--include-managed-config", "--",
"bash", "-lc", "printf %s 'hello world'"]
bash -lc payload argv:
["printf", "%s", "hello world"]
```
A production implementation could execute that SSH command. The
integration fixture prints it and parses the result back into arguments,
verifying the complete flow:
```text
model invokes outer wrapper
-> zsh-fork starts wrapper under :workspace
-> wrapper execs allowlisted Python script
-> prefix rule restarts Python script unsandboxed
-> Python script inherits CODEX_PERMISSION_PROFILE=:workspace
-> Python script verifies :workspace is allowlisted
-> remote command runs codex sandbox -P :workspace
with --include-managed-config
-> nested sandbox honors managed enterprise requirements
```
This gives the trusted helper access to resources outside the local
sandbox—such as SSH credentials—while ensuring that it can select only
an explicitly authorized profile and that work on the remote host
remains subject to the organization's managed requirements.
## What changed
- Inject `CODEX_PERMISSION_PROFILE` after shell environment policy
evaluation so the active profile wins over inherited or configured stale
values.
- Apply the variable to both `shell_command` and unified `exec_command`,
including local, zsh-fork, and remote exec-server paths.
- Remove stale values when the session has no active named profile.
- Preserve the current profile value when loading a shell snapshot so a
parent snapshot cannot restore an older profile.
## Testing
- Added classic-shell integration coverage proving an exact prefix rule
can run a `require_escalated` script outside the `:workspace` sandbox
while preserving `CODEX_PERMISSION_PROFILE=:workspace`.
- Added zsh-fork integration coverage in which the model invokes an
outer zsh wrapper, an inner allowlisted `remote_bash.py` runs
unsandboxed, and its printed SSH command reconstructs the inherited
`:workspace` sandbox with `--include-managed-config` while preserving
every argument after `--`.
- The example helper treats `CODEX_PERMISSION_PROFILE` as untrusted and
validates it against `ALLOWED_PROFILES` before constructing the nested
command.
- Assert that the reconstructed sandbox command includes
`--include-managed-config` so nested use of the inherited profile cannot
bypass managed enterprise requirements.
- Added coverage for overriding and removing stale profile values.
- Verified `shell_command` receives the selected active profile.
- Added shell snapshot coverage using `printenv
CODEX_PERMISSION_PROFILE`.
A zero interval lets callers request a reminder at every
otherwise-eligible inference boundary.
## Validation
- just test -p codex-core load_config_resolves_current_time_reminder
## Why
`codex sandbox` accepts a single named permissions profile, so the
existing plural `--permissions-profile` spelling is misleading. The
canonical flag and its help text should use the singular form without
breaking scripts that already use the old spelling.
## What changed
- Make `--permission-profile` the canonical flag for all sandbox
backends.
- Keep `--permissions-profile` as a hidden backwards-compatible alias.
- Cover the canonical spelling, legacy alias, and help visibility with
regression tests.
## Testing
Ran `just c sandbox --help` and verified I saw:
```shell
-P, --permission-profile <NAME>
Named permissions profile to apply from the active configuration stack
```
## Why
Helper threads such as task title generation can request a model ID that
is valid for the default OpenAI provider but unavailable from the active
provider. With Amazon Bedrock, `gpt-5.4-mini` is rejected while the
provider static catalog exposes Bedrock model IDs such as
`openai.gpt-5.5` and `openai.gpt-5.4`. This causes repeated background
404s and can surface a misleading turn error even when the main turn
succeeds.
Clients need an explicit way to ask app-server to resolve an unavailable
helper model to the active provider default. That fallback must remain
limited to providers with an authoritative static catalog so custom or
dynamically discovered model IDs are not rewritten based on an
incomplete catalog.
Fixes#28741.
## What changed
- Add the experimental `allowProviderModelFallback` option to
`thread/start`, defaulting to `false` to preserve existing behavior.
- Thread the option through thread creation and model selection.
- When enabled for a static model manager, preserve requested models
present in the catalog and replace unavailable models with the provider
default.
- Continue preserving explicit model IDs for dynamic model managers
without fetching a catalog solely to validate them.
- Document the new `thread/start` behavior in the app-server API
overview.
## Test
Temporary test-client harness:
```
ThreadStartParams {
model: Some("gpt-5.4-mini".to_string()),
allow_provider_model_fallback: true,
..Default::default()
}
```
Command:
```
CODEX_HOME=/tmp/codex-bedrock-thread-start-home \
CODEX_E2E_BEDROCK_THREAD_START_ONLY=1 \
./target/debug/codex-app-server-test-client \
--codex-bin ./target/debug/codex \
-c 'model_provider="amazon-bedrock"' \
send-message-v2 --experimental-api ignored
```
Relevant output:
```
> "method": "thread/start",
> "params": {
> "model": "gpt-5.4-mini",
> "modelProvider": null,
> "allowProviderModelFallback": true,
> ...
> }
< "result": {
< "model": "openai.gpt-5.5",
< "modelProvider": "amazon-bedrock",
< ...
< }
```
## Summary
- Record bounded connection, request, and process lifecycle metrics.
- Report active gauges from callbacks on every collection, including
delta exports.
- Serialize active-count updates so concurrent starts and finishes
cannot publish stale values.
- Serialize process exit, explicit termination, and shutdown through the
process registry so exactly one completion result wins.
- Keep the implementation small with single-owner RAII guards and one
real OTLP/HTTP integration test using the existing `wiremock`
dependency.
## Root cause
Process exit and session shutdown previously used cloned completion
state. That avoided duplicate emission, but it duplicated lifecycle
ownership and made the ordering harder to reason about. The process
registry mutex already defines the lifecycle ordering, so the final
implementation stores the metric guard and termination flag directly on
the process entry. Whichever path claims the entry first owns the
completion result.
Production metric export uses delta temporality. Event-only synchronous
gauge recordings disappear after the next collection when no count
changes, so active counts now use observable callbacks that report
current state on every collection.
The cleanup also removes the constant `result="accepted"` connection
tag, redundant route and response assertions, a custom HTTP collector,
and fallback initialization machinery that did not add behavior.
## Stack
Review and land this stack in order:
1. #27466 — trace exec-server JSON-RPC requests
2. #27467 — record bounded connection, request, and process lifecycle
metrics **(this PR)**
3. #27470 — observe remote registration and Noise rendezvous lifecycle
## Validation
- `just test -p codex-exec-server --lib` (158 passed)
- `just test -p codex-cli --test exec_server` (3 passed)
- `just test -p codex-otel
observable_gauge_is_collected_on_every_delta_snapshot` (1 passed)
- `CARGO_BUILD_JOBS=1 just fix -p codex-otel -p codex-exec-server`
- `just fmt`
- `git diff --check`