codex

feat(core) update Personality on turn (#9644 )

## Summary
Support updating Personality mid-Thread via UserTurn/OverwriteTurn. This
is explicitly unused by the clients so far, to simplify PRs - app-server
and tui implementations will be follow-ups.

## Testing
- [x] added integration tests

Dylan Hurd · 2026-01-22 12:04:23 -08:00

8b3521ee77

Support end_turn flag (#9698 )

Experimental flag that signals the end of the turn.

pakrym-oai · 2026-01-22 17:27:48 +00:00

b511c38ddb

feat(core) ModelInfo.model_instructions_template (#9597 )

## Summary
#9555 is the start of a rename, so I'm starting to standardize here.
Sets up `model_instructions` templating with a strongly-typed object for
injecting a personality block into the model instructions.

## Testing
- [x] Added tests
- [x] Ran locally

Dylan Hurd · 2026-01-21 18:11:18 -08:00

96a72828be

fix: prevent repeating interrupted turns (#9043 )

## What
Record a model-visible `<turn_aborted>` marker in history when a turn is
interrupted, and treat it as a session prefix.

## Why
When a turn is interrupted, Codex emits `TurnAborted` but previously did
not persist anything model-visible in the conversation history. On the
next user turn, the model can’t tell the previous work was aborted and
may resume/repeat earlier actions (including duplicated side effects
like re-opening PRs).

Fixes: https://github.com/openai/codex/issues/9042

## How
On `TurnAbortReason::Interrupted`, append a hidden user message
containing a `<turn_aborted>…</turn_aborted>` marker and flush.
Treat `<turn_aborted>` like `<environment_context>` for session-prefix
filtering.
Add a regression test to ensure follow-up turns don’t repeat side
effects from an aborted turn.

## Testing
`just fmt`
`just fix -p codex-core`
`cargo test -p codex-core -- --test-threads=1`
`cargo test --all-features -- --test-threads=1`

---------

Co-authored-by: Skylar Graika <sgraika127@gmail.com>
Co-authored-by: jif-oai <jif@openai.com>
Co-authored-by: Eric Traut <etraut@openai.com>

Skylar Graika · 2026-01-20 13:07:28 -08:00

b236f1c95d

Act on reasoning-included per turn (#9402 )

- Reset reasoning-included flag each turn and update compaction test

Ahmed Ibrahim · 2026-01-19 11:23:25 -08:00

b11e96fb04

chore(core) Create instructions module (#9422 )

## Summary
We have a variety of things we refer to as instructions in the code
base: our current canonical terms are:
- base instructions (raw string)
- developer instructions (has a type in protocol)
- user instructions

We also have `instructions` floating around in various places. We should
standardize on the above, and start using types to prevent them from
ending up in the wrong place. There will be additional PRs, but I'm
going to keep these small so we can easily follow them!

## Testing
- [x] Tests pass, this is purely a file move

Dylan Hurd · 2026-01-17 16:01:26 -08:00

bffe9b33e9

Fix token estimate during compaction (#9337 )

This addresses #9287

Eric Traut · 2026-01-15 19:48:11 -08:00

1fc72c647f

feat: return an error if the image sent by the user is a bad image (#9146 )

## Before
When we detect an `InvalidImageRequest`, we replace the image by a
placeholder and keep going

## Now
In such `InvalidImageRequest`, we check if the image is due to a user
message or a tool call output. For tool call output we still replace it
with a placeholder to avoid breaking the agentic loop bu tif this is
because of a user message, we send an error to the user

jif-oai · 2026-01-14 09:07:45 +00:00

dc3deaa3e7

clean: all history cloning (#8916 )

jif-oai · 2026-01-08 18:17:18 +00:00

69898e3dba

feat: add a few metrics (#8910 )

jif-oai · 2026-01-08 15:39:57 +00:00

5522663f92

remove unnecessary todos (#8842 )

> // todo(aibrahim): why are we passing model here while it can change?

we update it on each turn with `.with_model`

> //TODO(aibrahim): run CI in release mode.

although it's good to have, release builds take double the time tests
take.

> // todo(aibrahim): make this async function

we figured out another way of doing this sync

Ahmed Ibrahim · 2026-01-07 10:43:10 -08:00

c31960b13a

Merge Modelfamily into modelinfo (#8763 )

- Merge ModelFamily into ModelInfo
- Remove logic for adding instructions to apply patch
- Add compaction limit and visible context window to `ModelInfo`

Ahmed Ibrahim · 2026-01-07 10:35:09 -08:00

9179c9deac

chore: unify conversation with thread name (#8830 )

Done and verified by Codex + refactor feature of RustRover

jif-oai · 2026-01-07 17:04:53 +00:00

116059c3a0

feat(app-server): thread/rollback API (#8454 )

Add `thread/rollback` to app-server to support IDEs undo-ing the last N
turns of a thread.

For context, an IDE partner will be supporting an "undo" capability
where the IDE (the app-server client) will be responsible for reverting
the local changes made during the last turn. To support this well, we
also need a way to drop the last turn (or more generally, the last N
turns) from the agent's context. This is what `thread/rollback` does.

**Core idea**: A Thread rollback is represented as a persisted event
message (EventMsg::ThreadRollback) in the rollout JSONL file, not by
rewriting history. On resume, both the model's context (core replay) and
the UI turn list (app-server v2's thread history builder) apply these
markers so the pruned history is consistent across live conversations
and `thread/resume`.

Implementation notes:
- Rollback only affects agent context and appends to the rollout file;
clients are responsible for reverting files on disk.
- If a thread rollback is currently in progress, subsequent
`thread/rollback` calls are rejected.
- Because we use `CodexConversation::submit` and codex core tracks
active turns, returning an error on concurrent rollbacks is communicated
via an `EventMsg::Error` with a new variant
`CodexErrorInfo::ThreadRollbackFailed`. app-server watches for that and
sends the BAD_REQUEST RPC response.

Tests cover thread rollbacks in both core and app-server, including when
`num_turns` > existing turns (which clears all turns).

**Note**: this explicitly does **not** behave like `/undo` which we just
removed from the CLI, which does the opposite of what `thread/rollback`
does. `/undo` reverts local changes via ghost commits/snapshots and does
not modify the agent's context / conversation history.

Owen Lin · 2026-01-06 21:23:48 +00:00

8b7ec31ba7

Do not panic when session contains a tool call without an output (#8048 )

Normally, all tool calls within a saved session should have a response,
but there are legitimate reasons for the response to be missing. This
can occur if the user canceled the call or there was an error of some
sort during the rollout. We shouldn't panic in this case.

This is a partial fix for #7990

Eric Traut · 2025-12-14 22:16:49 -08:00

1e3cad95c0

Remote compact for API-key users (#7835 )

pakrym-oai · 2025-12-12 10:05:02 -08:00

b3ddd50eee

fix: ignore ghost snapshots in token consumption (#7638 )

jif-oai · 2025-12-05 13:57:24 +00:00

e91bb6b947

feat: retroactive image placeholder to prevent poisoning (#6774 )

If an image can't be read by the API, it will poison the entire history,
preventing any new turn on the conversation.
This detect such cases and replace the image by a placeholder

jif-oai · 2025-12-03 11:35:56 +00:00

51307eaf07

fix: disable review rollout filtering (#7371 )

jif-oai · 2025-12-01 09:04:13 +00:00

a421eba31f

feat: detached review (#7292 )

jif-oai · 2025-11-28 11:34:57 +00:00

aaec8abf58

chore: use proxy for encrypted summary (#7252 )

jif-oai · 2025-11-24 16:51:47 +00:00

99bcb90353

Account for encrypted reasoning for auto compaction (#7113 )

- The total token used returned from the api doesn't account for the
reasoning items before the assistant message
- Account for those for auto compaction
- Add the encrypted reasoning effort in the common tests utils
- Add a test to make sure it works as expected

Ahmed Ibrahim · 2025-11-22 03:06:45 +00:00

b519267d05

Delete tiktoken-rs (#7018 )

pakrym-oai · 2025-11-20 11:15:04 -08:00

52d0ec4cd8

Move shell to use truncate_text (#6842 )

Move shell to use the configurable `truncate_text`

---------

Co-authored-by: pakrym-oai <pakrym@openai.com>

Ahmed Ibrahim · 2025-11-19 01:56:08 -08:00

efebc62fb7

Add the utility to truncate by tokens (#6746 )

- This PR is to make it on path for truncating by tokens. This path will
be initially used by unified exec and context manager (responsible for
MCP calls mainly).
- We are exposing new config `calls_output_max_tokens`
- Use `tokens` as the main budget unit but truncate based on the model
family by Introducing `TruncationPolicy`.
- Introduce `truncate_text` as a router for truncation based on the
mode.

In next PRs:
- remove truncate_with_line_bytes_budget
- Add the ability to the model to override the token budget.

Ahmed Ibrahim · 2025-11-18 11:36:23 -08:00

3de8790714

feat: remote compaction (#6795 )

Co-authored-by: pakrym-oai <pakrym@openai.com>

jif-oai · 2025-11-18 16:51:16 +00:00

838531d3e4

Refactor truncation helpers into its own file (#6683 )

That's to centralize the truncation in one place. Next step would be to
make only two methods public: one with bytes/lines and one with tokens.

Ahmed Ibrahim · 2025-11-15 06:44:23 +00:00

94dfb211af

Avoid double truncation (#6631 )

1. Avoid double truncation by giving 10% above the tool default constant
2. Add tests that fails when const = 1

Ahmed Ibrahim · 2025-11-13 16:59:31 -08:00

9890ceb939

feat: proxy context left after compaction (#6597 )

jif-oai · 2025-11-13 16:54:03 +01:00

2a417c47ac

refactor Conversation history file into its own directory (#6229 )

This is just a refactor of `conversation_history` file by breaking it up
into multiple smaller ones with helper. This refactor will help us move
more functionality related to context management here. in a clean way.

Ahmed Ibrahim · 2025-11-05 10:49:35 -08:00

1a89f70015

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