**Stack position:** [5 of 7]
## Summary
This PR adds `Op::ThreadSettings`, a queued settings-only update
mechanism for changing stored thread settings without starting a new
turn. It also removes the legacy `Op::OverrideTurnContext` in the same
layer, so reviewers can see the replacement and deletion together.
## Changes
- Add `Op::ThreadSettings` for settings-only queued updates.
- Emit `ThreadSettingsApplied` with the effective thread settings
snapshot after core applies an update.
- Route settings-only updates through the same submission queue as user
input.
- Migrate remaining `OverrideTurnContext` tests and callers to the
queued `Op::ThreadSettings` path.
- Delete `Op::OverrideTurnContext` from the core protocol and submission
loop.
This stack addresses #20656 and #22090.
## Stack
1. [1 of 7] [Add thread settings to
UserInput](https://github.com/openai/codex/pull/23080)
2. [2 of 7] [Remove
UserInputWithTurnContext](https://github.com/openai/codex/pull/23081)
3. [3 of 7] [Remove
UserTurn](https://github.com/openai/codex/pull/23075)
4. [4 of 7] [Placeholder for OverrideTurnContext
cleanup](https://github.com/openai/codex/pull/23087)
5. [5 of 7] [Replace OverrideTurnContext with
ThreadSettings](https://github.com/openai/codex/pull/22508) (this PR)
6. [6 of 7] [Add app-server thread settings
API](https://github.com/openai/codex/pull/22509)
7. [7 of 7] [Sync TUI thread
settings](https://github.com/openai/codex/pull/22510)
## Summary
Related to
https://openai.slack.com/archives/C095U48JNL9/p1777537279707449
TLDR:
We update the meaning of session ids and thread ids:
* thread_id stays as now
* session_id become a shared id between every thread under a /root
thread (i.e. every sub-agent share the same session id)
This PR introduces an explicit `SessionId` and threads it through the
protocol/client boundary so `session_id` and `thread_id` can diverge
when they need to, while preserving compatibility for older serialized
`session_configured` events.
---------
Co-authored-by: Codex <noreply@openai.com>
Keep extracting memories out of core and moving the write trigger in the
app-server
This is temporary and it should move at the client level as a follow-up
This makes core fully independant from `codex-memories-write`
---------
Co-authored-by: Codex <noreply@openai.com>
Eric TrautandGitHub
