## Why
Importing large external-agent session histories currently starts a full
live Codex thread for every imported session. This initializes unrelated
runtime systems and repeats expensive transcript, metadata, hashing, and
ledger work.
On a 50-session, 238 MiB fixture, the existing path took roughly 70
seconds to complete the import and 77 seconds end to end.
## What changed
- Persist imported sessions directly through `ThreadStore` instead of
starting full live threads.
- Process imports through a bounded five-session pipeline.
- Parse, extract, and hash each source file in one pass.
- Move blocking source preparation onto the blocking thread pool.
- Reuse prepared content hashes and update the import ledger once per
batch.
- Avoid metadata readback for newly written rollouts.
- Preserve imported conversation history and visible thread metadata.
- Keep the implementation out of `codex-core` and avoid changes to the
public `ThreadStore` trait.
## Performance
For the same 50-session, 238 MiB fixture:
| Path | Import completion | End to end |
| --- | ---: | ---: |
| Existing import | 69.61s | 76.62s |
| This change | 5.95s | 6.58s |
All 50 sessions imported successfully with no warnings or contention
signals.
## Validation
- `just test -p codex-external-agent-sessions`
- `just test -p codex-app-server external_agent_config_import`
- Verified imports do not initialize unrelated required MCP servers.
- Verified previously imported source versions are skipped and changed
sources can be imported again.
- Verified imported rollouts remain readable through thread listing and
history APIs.
Summary:
- Return from external agent import before session history import
finishes
- Run session import work in the background and emit the existing
completion notification when it is done
- Serialize session imports so duplicate requests do not create
duplicate imported threads
Verification:
- cargo test -p codex-app-server external_agent_config_
- cargo test -p codex-external-agent-sessions
- just fix -p codex-app-server
- just fix -p codex-external-agent-sessions
- git diff --check
## Summary
- Support Claude Code `ai-title` / `aiTitle` records when detecting and
importing external agent sessions.
- Preserve existing `custom-title` / `customTitle` precedence; only fall
back to `aiTitle` when no custom title is present.
- Add coverage for both detection and import title selection, including
the custom-title-over-ai-title case.
## Testing
- `cargo test -p codex-external-agent-sessions`
- `just fix -p codex-external-agent-sessions`
## Summary
This extends external agent detection/import beyond config artifacts so
Codex can detect recent sessions files from the external agent home and
import them into Codex rollout history.
## What changed
- Added a focused `external_agent_sessions` module for:
- session discovery
- source-record parsing
- rollout construction
- import ledger tracking
- Wired session detection/import into the app-server external agent
config API.
- Added compaction handling so large imported sessions can be resumed
safely before the first follow-up turn.
## Testing
Added coverage for:
- recent-session detection
- custom-title handling
- recency filtering
- dedupe and re-detect-after-source-change behavior
- visible imported turn construction
- backward-compatible import payload deserialization
- end-to-end RPC import flow
- rejection of undetected session paths
- repeat-import behavior
- large-session compaction before first follow-up
Ran:
- `cargo test -p codex-app-server external_agent_config_import_ --test
all`
stefanstokic-oaiandGitHub
alexsong-oaiandGitHub