rm `remote_models` feature flag.
We see issues like #11527 when a user has `remote_models` disabled, as
we always use the default fallback `ModelInfo`. This causes issues with
model performance.
Builds on #11690, which helps by warning the user when they are using
the default fallback. This PR will make that happen much less frequently
as an accidental consequence of disabling `remote_models`.
## Summary
This PR centralizes model-visible state diffing for turn context updates
into one module, while keeping existing behavior and call sites stable.
### What changed
- Added `core/src/context_updates.rs` with the consolidated diffing
logic for:
- environment context updates
- permissions/policy updates
- collaboration mode updates
- model-instruction switch updates
- personality updates
- Added `BuildSettingsUpdateItemsParams` so required dependencies are
passed explicitly.
- Updated `Session::build_settings_update_items` in `core/src/codex.rs`
to delegate to the centralized module.
- Reused the same centralized `personality_message_for` helper from
initial-context assembly to avoid duplicated logic.
- Registered the new module in `core/src/lib.rs`.
## Why
This is a minimal, shippable step toward the model-visible-state design:
all state diff decisions for turn-context update items now live in one
place, improving reviewability and reducing drift risk without expanding
scope.
## Behavior
- Intended to be behavior-preserving.
- No protocol/schema changes.
- No call-site behavior changes beyond routing through the new
centralized logic.
## Testing
Ran targeted tests in this worktree:
- `cargo test -p codex-core
build_settings_update_items_emits_environment_item_for_network_changes`
- `cargo test -p codex-core collaboration_instructions --test all`
Both passed.
## Codex author
`codex resume 019c540f-3951-7352-a3fa-6f07b834d4ce`
The `model_supports_reasoning_summaries` config option was originally
added so users could enable reasoning for custom models (models that
codex doesn't know about). This is how it was documented in the source,
but its implementation didn't match. It was implemented such that it can
also be used to disable reasoning for models that otherwise support
reasoning. This leads to bad behavior for some reasoning models like
`gpt-5.3-codex`. Diagnosing this is difficult, and it has led to many
support issues.
This PR changes the handling of `model_supports_reasoning_summaries` so
it matches its original documented behavior. If it is set to false, it
is a no-op. That is, it never disables reasoning for models that are
known to support reasoning. It can still be used for its intended
purpose -- to enable reasoning for unknown models.
js_repl_reset previously raced with in-flight/new js_repl executions
because reset() could clear exec_tool_calls without synchronizing with
execute(). In that window, a running exec could lose its per-exec
tool-call context, and subsequent kernel RunTool messages would fail
with js_repl exec context not found. The fix serializes reset and
execute on the same exec_lock, so reset cannot run concurrently with
exec setup/teardown. We also keep the timeout path safe by performing
reset steps inline while execute() already holds the lock, avoiding
re-entrant lock acquisition. A regression test now verifies that reset
waits for the exec lock and does not clear tool-call state early.
Remove the waiting loop in `reset` so it no longer blocks on potentially
hanging exec tool calls + add `clear_all_exec_tool_calls_map` to drain
the map and notify waiters so `reset` completes immediately
## Summary
Fixes a few things in our exec_policy handling of prefix_rules:
1. Correctly match redirects specifically for exec_policy parsing. i.e.
if you have `prefix_rule(["echo"], decision="allow")` then `echo hello >
output.txt` should match - this should fix#10321
2. If there already exists any rule that would match our prefix rule
(not just a prompt), then drop it, since it won't do anything.
## Testing
- [x] Updated unit tests, added approvals ScenarioSpecs
Add per-turn notice when a request is downgraded to a fallback model due
to cyber safety checks.
**Changes**
- codex-api: Emit a ServerModel event based on the openai-model response
header and/or response payload (SSE + WebSocket), including when the
model changes mid-stream.
- core: When the server-reported model differs from the requested model,
emit a single per-turn warning explaining the reroute to gpt-5.2 and
directing users to Trusted
Access verification and the cyber safety explainer.
- app-server (v2): Surface these cyber model-routing warnings as
synthetic userMessage items with text prefixed by Warning: (and document
this behavior).
Charles Cunningham