Files
codex/codex-rs/thread-store/src/local/create_thread.rs
Owen Lin 5267e805fb feat(app-server): add history_mode to thread (#29927)
## Description

This PR adds a new `historyMode = "legacy" | "paginated"` to `Thread`.
This will be stored in `SessionMeta` in the JSONL rollout file and as a
new column in the SQLite thread_metadata table, and exposed on
`thread/start` and on the `Thread` object in app-server.

## What changed

- Added canonical `ThreadHistoryMode` with `legacy` and `paginated`,
defaulting old and new SessionMeta to `legacy`.
- Carried `history_mode` through core session config, ThreadStore stored
metadata, local/in-memory stores, rollout metadata extraction, and the
existing SQLite `threads` table.
- Added experimental `historyMode` to app-server v2 `Thread` and
`thread/start`.
- Made paginated stored threads metadata-discoverable but unsupported
for legacy full-history reads, `load_history`, live resume, and create
paths.
- Regenerated app-server schema fixtures and added
protocol/state/thread-store/app-server coverage for persistence and
fail-closed behavior.

## Compatibility floor
Because users may be running various versions of Codex binaries on the
same machine (TUI, Codex App, etc.), we will need to establish a
compatibility floor for upcoming paginated threads, which will change
how thread storage reads and writes work.

The overall plan here:
```
Release N:
- Add historyMode to SessionMeta / Thread / SQLite metadata.
- Teach binaries to understand paginated threads.
- If a binary sees `historyMode="paginated"` but does not support the paginated contract, it refuses to resume/mutate the thread.
- Default remains `"legacy"`.

Release N+1:
- First-party clients start opting into paginated threads where appropriate.
- Internal dogfood / staged rollout.
- Measure old-client usage and paginated-thread unsupported errors.

Release N+2:
- Only after Release N+ is overwhelmingly deployed, make paginated the default.
- Accept that a small tail of N-1-or-older binaries may not understand paginated threads.
```

The important behavior change is fail-closed handling for a binary that
encounters a persisted `paginated` thread before it knows how to fully
support paginated history. In app-server, if a thread is `paginated`, we
will:

- allow metadata-only discovery paths like `thread/list` and
`thread/read(includeTurns=false)`, so clients can still see the thread
and inspect its `historyMode`
- reject legacy full-history/live-thread paths like
`thread/read(includeTurns=true)` and `thread/resume` with an unsupported
JSON-RPC error
- avoid silently treating an unknown or future `historyMode` as `legacy`

Under the hood, the ThreadStore layer also rejects legacy operations
that would need to load or replay the full thread history for a
paginated thread. That gives us the behavior we want for Release N:
future paginated threads are visible, but this binary fails closed
instead of trying to operate on them as if they were legacy threads.
2026-06-26 09:12:42 -07:00

53 lines
1.8 KiB
Rust

use super::LocalThreadStore;
use crate::CreateThreadParams;
use crate::ThreadStoreError;
use crate::ThreadStoreResult;
use crate::error::reject_paginated_history_mode;
use codex_protocol::protocol::ThreadMemoryMode;
use codex_rollout::RolloutConfig;
use codex_rollout::RolloutRecorder;
use codex_rollout::RolloutRecorderParams;
pub(super) async fn create_thread(
store: &LocalThreadStore,
params: CreateThreadParams,
) -> ThreadStoreResult<RolloutRecorder> {
reject_paginated_history_mode(params.history_mode)?;
let cwd = params
.metadata
.cwd
.clone()
.ok_or_else(|| ThreadStoreError::InvalidRequest {
message: "local thread store requires a cwd".to_string(),
})?;
let config = RolloutConfig {
codex_home: store.config.codex_home.clone(),
sqlite_home: store.config.sqlite_home.clone(),
cwd,
model_provider_id: params.metadata.model_provider.clone(),
generate_memories: matches!(params.metadata.memory_mode, ThreadMemoryMode::Enabled),
};
RolloutRecorder::new(
&config,
RolloutRecorderParams::new(
params.thread_id,
params.forked_from_id,
params.parent_thread_id,
params.source,
params.thread_source,
params.originator,
params.base_instructions,
params.dynamic_tools,
)
.with_session_id(params.session_id)
.with_selected_capability_roots(params.selected_capability_roots)
.with_multi_agent_version(params.multi_agent_version)
.with_history_mode(params.history_mode)
.with_initial_window_id(params.initial_window_id),
)
.await
.map_err(|err| ThreadStoreError::Internal {
message: format!("failed to initialize local thread recorder: {err}"),
})
}