## Why Reverts #20689 to restore the previous optional state DB plumbing. The conflict resolution keeps the newer installation ID and session/thread identity changes that landed after #20689, while removing the mandatory state DB and agent graph store dependency from ThreadManager construction. ## What changed - Restored `Option<StateDbHandle>` through app-server, MCP server, prompt debug, and test entry points. - Removed the `codex-core` dependency on `codex-agent-graph-store` and reverted descendant lookup back to the existing state DB path when available. - Kept newer `installation_id` forwarding by passing it beside the optional DB handle. - Kept local thread-name updates working when the optional state DB handle is absent. ## Validation - `git diff --check` - `cargo test -p codex-thread-store` - `cargo test -p codex-state -p codex-rollout -p codex-app-server-protocol` - Attempted `env CARGO_INCREMENTAL=0 cargo test -p codex-core -p codex-app-server -p codex-app-server-client -p codex-mcp-server -p codex-thread-manager-sample -p codex-tui`; blocked locally by a rustc ICE while compiling `v8 v146.4.0` with `rustc 1.93.0 (254b59607 2026-01-19)` on `aarch64-apple-darwin`.
codex-app-server-client
Shared in-process app-server client used by conversational CLI surfaces:
codex-execcodex-tui
Purpose
This crate centralizes startup and lifecycle management for an in-process
codex-app-server runtime, so CLI clients do not need to duplicate:
- app-server bootstrap and initialize handshake
- in-memory request/event transport wiring
- lifecycle orchestration around caller-provided startup identity
- graceful shutdown behavior
Startup identity
Callers pass both the app-server SessionSource and the initialize
client_info.name explicitly when starting the facade.
That keeps thread metadata (for example in thread/list and thread/read)
aligned with the originating runtime without baking TUI/exec-specific policy
into the shared client layer.
Transport model
The in-process path uses typed channels:
- client -> server:
ClientRequest/ClientNotification - server -> client:
InProcessServerEventServerRequestServerNotificationLegacyNotification
JSON serialization is still used at external transport boundaries (stdio/websocket), but the in-process hot path is typed.
Typed requests still receive app-server responses through the JSON-RPC result envelope internally. That is intentional: the in-process path is meant to preserve app-server semantics while removing the process boundary, not to introduce a second response contract.
Bootstrap behavior
The client facade starts an already-initialized in-process runtime, but thread bootstrap still follows normal app-server flow:
- caller sends
thread/startorthread/resume - app-server returns the immediate typed response
- richer session metadata may arrive later as a
SessionConfiguredlegacy event
Surfaces such as TUI and exec may therefore need a short bootstrap phase where they reconcile startup response data with later events.
Backpressure and shutdown
- Queues are bounded and use
DEFAULT_IN_PROCESS_CHANNEL_CAPACITYby default. - Full queues return explicit overload behavior instead of unbounded growth.
shutdown()performs a bounded graceful shutdown and then aborts if timeout is exceeded.
If the client falls behind on event consumption, the worker emits
InProcessServerEvent::Lagged and may reject pending server requests so
approval flows do not hang indefinitely behind a saturated queue.