## Problem
When a user resumed or forked a session, the TUI could render the
restored thread history immediately, but it did not receive token usage
until a later model turn emitted a fresh usage event. That left the
context/status UI blank or stale during the exact window where the user
expects resumed state to look complete. Core already reconstructed token
usage from the rollout; the missing behavior was app-server lifecycle
replay to the client that just attached.
## Mental model
Token usage has two representations. The rollout is the durable source
of historical `TokenCount` events, and the core session cache is the
in-memory snapshot reconstructed from that rollout on resume or fork.
App-server v2 clients do not read core state directly; they learn about
usage through `thread/tokenUsage/updated`. The fix keeps those roles
separate: core exposes the restored `TokenUsageInfo`, and app-server
sends one targeted notification after a successful `thread/resume` or
`thread/fork` response when that restored snapshot exists.
This notification is not a new model event. It is a replay of
already-persisted state for the client that just attached. That
distinction matters because using the normal core event path here would
risk duplicating `TokenCount` entries in the rollout and making future
resumes count historical usage twice.
## Non-goals
This change does not add a new protocol method or payload shape. It
reuses the existing v2 `thread/tokenUsage/updated` notification and the
TUI’s existing handler for that notification.
This change does not alter how token usage is computed, accumulated,
compacted, or written during turns. It only exposes the token usage that
resume and fork reconstruction already restored.
This change does not broadcast historical usage replay to every
subscribed client. The replay is intentionally scoped to the connection
that requested resume or fork so already-attached clients are not
surprised by an old usage update while they may be rendering live
activity.
## Tradeoffs
Sending the usage notification after the JSON-RPC response preserves a
clear lifecycle order: the client first receives the thread object, then
receives restored usage for that thread. The tradeoff is that usage is
still a notification rather than part of the `thread/resume` or
`thread/fork` response. That keeps the protocol shape stable and avoids
duplicating usage fields across response types, but clients must
continue listening for notifications after receiving the response.
The helper selects the latest non-in-progress turn id for the replayed
usage notification. This is conservative because restored usage belongs
to completed persisted accounting, not to newly attached in-flight work.
The fallback to the last turn preserves a stable wire payload for
unusual histories, but histories with no meaningful completed turn still
have a weak attribution story.
## Architecture
Core already seeds `Session` token state from the last persisted rollout
`TokenCount` during `InitialHistory::Resumed` and
`InitialHistory::Forked`. The new core accessor exposes the complete
`TokenUsageInfo` through `CodexThread` without giving app-server direct
session mutation authority.
App-server calls that accessor from three lifecycle paths: cold
`thread/resume`, running-thread resume/rejoin, and `thread/fork`. In
each path, the server sends the normal response first, then calls a
shared helper that converts core usage into
`ThreadTokenUsageUpdatedNotification` and sends it only to the
requesting connection.
The tests build fake rollouts with a user turn plus a persisted token
usage event. They then exercise `thread/resume` and `thread/fork`
without starting another model turn, proving that restored usage arrives
before any next-turn token event could be produced.
## Observability
The primary debug path is the app-server JSON-RPC stream. After
`thread/resume` or `thread/fork`, a client should see the response
followed by `thread/tokenUsage/updated` when the source rollout includes
token usage. If the notification is absent, check whether the rollout
contains an `event_msg` payload of type `token_count`, whether core
reconstruction seeded `Session::token_usage_info`, and whether the
connection stayed attached long enough to receive the targeted
notification.
The notification is sent through the existing
`OutgoingMessageSender::send_server_notification_to_connections` path,
so existing app-server tracing around server notifications still
applies. Because this is a replay, not a model turn event, debugging
should start at the resume/fork handlers rather than the turn event
translation in `bespoke_event_handling`.
## Tests
The focused regression coverage is `cargo test -p codex-app-server
emits_restored_token_usage`, which covers both resume and fork. The core
reconstruction guard is `cargo test -p codex-core
record_initial_history_seeds_token_info_from_rollout`.
Formatting and lint/fix passes were run with `just fmt`, `just fix -p
codex-core`, and `just fix -p codex-app-server`. Full crate test runs
surfaced pre-existing unrelated failures in command execution and plugin
marketplace tests; the new token usage tests passed in focused runs and
within the app-server suite before the unrelated command execution
failure.
This PR add an URI-based system to reference agents within a tree. This
comes from a sync between research and engineering.
The main agent (the one manually spawned by a user) is always called
`/root`. Any sub-agent spawned by it will be `/root/agent_1` for example
where `agent_1` is chosen by the model.
Any agent can contact any agents using the path.
Paths can be used either in absolute or relative to the calling agents
Resume is not supported for now on this new path
Add dynamic tools to rollout file for persistence & read from rollout on
resume. Ran a real example and spotted the following in the rollout
file:
```
{"timestamp":"2026-01-29T01:27:57.468Z","type":"session_meta","payload":{"id":"019c075d-3f0b-77e3-894e-c1c159b04b1e","timestamp":"2026-01-29T01:27:57.451Z","...."dynamic_tools":[{"name":"demo_tool","description":"Demo dynamic tool","inputSchema":{"additionalProperties":false,"properties":{"city":{"type":"string"}},"required":["city"],"type":"object"}}],"git":{"commit_hash":"ebc573f15c01b8af158e060cfedd401f043e9dfa","branch":"dev/cc/dynamic-tools","repository_url":"https://github.com/openai/codex.git"}}}
```
## Summary
This PR consolidates base_instructions onto SessionMeta /
SessionConfiguration, so we ensure `base_instructions` is set once per
session and should be (mostly) immutable, unless:
- overridden by config on resume / fork
- sub-agent tasks, like review or collab
In a future PR, we should convert all references to `base_instructions`
to consistently used the typed struct, so it's less likely that we put
other strings there. See #9423. However, this PR is already quite
complex, so I'm deferring that to a follow-up.
## Testing
- [x] Added a resume test to assert that instructions are preserved. In
particular, `resume_switches_models_preserves_base_instructions` fails
against main.
Existing test coverage thats assert base instructions are preserved
across multiple requests in a session:
- Manual compact keeps baseline instructions:
core/tests/suite/compact.rs:199
- Auto-compact keeps baseline instructions:
core/tests/suite/compact.rs:1142
- Prompt caching reuses the same instructions across two requests:
core/tests/suite/prompt_caching.rs:150 and
core/tests/suite/prompt_caching.rs:157
- Prompt caching with explicit expected string across two requests:
core/tests/suite/prompt_caching.rs:213 and
core/tests/suite/prompt_caching.rs:222
- Resume with model switch keeps original instructions:
core/tests/suite/resume.rs:136
- Compact/resume/fork uses request 0 instructions for later expected
payloads: core/tests/suite/compact_resume_fork.rs:215
### Description
- Remove the now-unused `instructions` field from the session metadata
to simplify SessionMeta and stop propagating transient instruction text
through the rollout recorder API. This was only saving
user_instructions, and was never being read.
- Stop passing user instructions into the rollout writer at session
creation so the rollout header only contains canonical session metadata.
### Testing
- Ran `just fmt` which completed successfully.
- Ran `just fix -p codex-protocol`, `just fix -p codex-core`, `just fix
-p codex-app-server`, `just fix -p codex-tui`, and `just fix -p
codex-tui2` which completed (Clippy fixes applied) as part of
verification.
- Ran `cargo test -p codex-protocol` which passed (28 tests).
- Ran `cargo test -p codex-core` which showed failures in a small set of
tests (not caused by the protocol type change directly):
`default_client::tests::test_create_client_sets_default_headers`,
several `models_manager::manager::tests::refresh_available_models_*`,
and `shell_snapshot::tests::linux_sh_snapshot_includes_sections` (these
tests failed in this CI run).
- Ran `cargo test -p codex-app-server` which reported several failing
integration tests (including
`suite::codex_message_processor_flow::test_codex_jsonrpc_conversation_flow`,
`suite::output_schema::send_user_turn_*`, and
`suite::user_agent::get_user_agent_returns_current_codex_user_agent`).
- `cargo test -p codex-tui` and `cargo test -p codex-tui2` were
attempted but aborted due to disk space exhaustion (`No space left on
device`).
------
[Codex
Task](https://chatgpt.com/codex/tasks/task_i_696bd8ce632483228d298cf07c7eb41c)
Summary:
- Add forked_from to SessionMeta/SessionConfiguredEvent and persist it
for forked sessions.
- Surface forked_from in /status for tui + tui2 and add snapshots.
Add support for returning threads by either `created_at` OR `updated_at`
descending. Previously core always returned threads ordered by
`created_at`.
This PR:
- updates core to be able to list threads by `updated_at` OR
`created_at` descending based on what the caller wants
- also update `thread/list` in app-server to expose this (default to
`created_at` if not specified)
All existing codepaths (app-server, TUI) still default to `created_at`,
so no behavior change is expected with this PR.
**Implementation**
To sort by `updated_at` is a bit nontrivial (whereas `created_at` is
easy due to the way we structure the folders and filenames on disk,
which are all based on `created_at`).
The most naive way to do this without introducing a cache file or sqlite
DB (which we have to implement/maintain) is to scan files in reverse
`created_at` order on disk, and look at the file's mtime (last modified
timestamp according to the filesystem) until we reach `MAX_SCAN_FILES`
(currently set to 10,000). Then, we can return the most recent N
threads.
Based on some quick and dirty benchmarking on my machine with ~1000
rollout files, calling `thread/list` with limit 50, the `updated_at`
path is slower as expected due to all the I/O:
- updated-at: average 103.10 ms
- created-at: average 41.10 ms
Those absolute numbers aren't a big deal IMO, but we can certainly
optimize this in a followup if needed by introducing more state stored
on disk.
**Caveat**
There's also a limitation in that any files older than `MAX_SCAN_FILES`
will be excluded, which means if a user continues a REALLY old thread,
it's possible to not be included. In practice that should not be too big
of an issue.
If a user makes...
- 1000 rollouts/day → threads older than 10 days won't show up
- 100 rollouts/day → ~100 days
If this becomes a problem for some reason, even more motivation to
implement an updated_at cache.
The second part of breaking up PR
https://github.com/openai/codex/pull/9116
Summary:
- Add `TextElement` / `ByteRange` to protocol user inputs and user
message events with defaults.
- Thread `text_elements` through app-server v1/v2 request handling and
history rebuild.
- Preserve UI metadata only in user input/events (not `ContentItem`)
while keeping local image attachments in user events for rehydration.
Details:
- Protocol: `UserInput::Text` carries `text_elements`;
`UserMessageEvent` carries `text_elements` + `local_images`.
Serialization includes empty vectors for backward compatibility.
- app-server-protocol: v1 defines `V1TextElement` / `V1ByteRange` in
camelCase with conversions; v2 uses its own camelCase wrapper.
- app-server: v1/v2 input mapping includes `text_elements`; thread
history rebuilds include them.
- Core: user event emission preserves UI metadata while model history
stays clean; history replay round-trips the metadata.
Implements:
```
thread/list
thread/start
thread/resume
thread/archive
```
along with their integration tests. These are relatively light wrappers
around the existing core logic, and changes to core logic are minimal.
However, an improvement made for developer ergonomics:
- `thread/start` and `thread/resume` automatically attaches a
conversation listener internally, so clients don't have to make a
separate `AddConversationListener` call like they do today.
For consistency, also updated `model/list` and `feedback/upload` (naming
conventions, list API params).
