Files
PaperClipAI/packages
DottaandClaude Opus 5.5 fc6e1b0346 perf(native): keep local Codex and OpenCode runners warm by default (#19888)
## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work.
> - When someone messages an agent, the turn must start fast. Time to
first token (TTFT) is a first-class metric.
> - The Phase 0 baseline (#19846) found that every local turn launches a
new runner and loads the provider session again, because `per_turn` is
the default lifecycle. That made a follow-up message slower than a new
task.
> - Warm runners keep the runner and provider session alive between
runs. #19874 fixed the defect that broke warm OpenCode follow-ups, and
#19879 bounds an idle warm runner whose controller dies.
> - This pull request makes warm the default for local Codex and
OpenCode agents, and migrates existing agents that only carried the old
creation default.
> - The benefit: follow-up TTFT p50 drops from 12.0 s to 4.7 s (Codex)
and from 21.7 s to 4.2 s (OpenCode), with no new restart-chaos failures.

## Linked Issues or Issue Description

Refs #19846 (TTFT baseline), #19852 (startup sub-spans), #19874 (warm
completion contract), #19879 (warm reconnect grace).

**What existing behavior does this improve?**
The default runner lifecycle for native agents, and how a follow-up
message starts.

**Current behavior**
Agent creation writes `lifecycleMode: "per_turn"` into every native
agent. Every follow-up launches a new runner and restores the provider
session: 4.2 s (Codex) and 16.3 s (OpenCode) at p50 before the turn
starts.

**Proposed behavior**
New native agents store no lifecycle. On a local target, an unset
lifecycle resolves to `warm` with the default 5-minute idle window for
Codex and OpenCode. Other harnesses, remote targets and managed
providers without warm support stay `per_turn`. An explicit choice
always wins. Migration 0443 clears the stored creation default from
existing agents, except where an edit set "Turn by turn" explicitly.

**Reason and benefit**
Measured locally (`doc/plans/2026-11-07-warm-follow-up-ttft.md`). Warm
follow-ups are 2.6–5× faster for Codex and OpenCode, and restart
recovery latency is equal or lower.

## What Changed

- `native-lifecycle.ts`: an unset `agentMode` resolves to warm (5-minute
idle window) for local `codex_app_server` and `opencode_server` agents.
`runtime-selection.ts` passes `localTarget`. Explicit `per_turn` or
`warm` wins. An admitted session keeps its persisted policy. ACPX Claude
stays `per_turn`: it relaunches its provider process on every follow-up
by design, so warm did not shorten its follow-up (10.7 s warm vs 10.5 s
per_turn).
- Creation and configuration writes no longer store `lifecycleMode:
"per_turn"` for Codex, Claude or OpenCode. This covers
`normalizePaperclipRunnerAdapterConfig` (runs on every create and
update), `paperclipRunnerTransitionConfig` (switching to the native
runner), `agent-runner-selection.ts`, `codex-local` `build-config.ts`,
and the simplified new-agent setup (`paperclipRunnerCreationLifecycle`
in `@paperclipai/shared`). Grok, Pi and Cursor keep their explicit
value.
- Agent form: the Runner lifecycle field shows the unset state as
"Automatic". "Turn by turn" and "Warm session" remain.
- Migration `0443_native_warm_follow_up_default.sql`: clears
`lifecycleMode = 'per_turn'` from native Codex, OpenCode and Claude
agents unless `agent_config_revisions` shows an edit that set it to
`per_turn`. Each migrated agent gets an `agent.updated` activity entry
with the old value (`actor_id =
migration:native-warm-follow-up-default`). Creation records no revision,
so a "Turn by turn" pick made at creation cannot be told apart from the
old default. The product owner approved migrating those agents. Claude
agents follow the default, which is `per_turn` today.
- Restart chaos harness and TTFT driver: `--lifecycle
per_turn|warm|default` (saved in the wave plan). `default` removes the
catalog's pinned lifecycle, so a wave exercises the real default path.
- Docs: `doc/DEVELOPING.md` "Runner lifecycle default", and the results
in `doc/plans/2026-11-07-warm-follow-up-ttft.md`, which also documents
baseline finding 4 (Claude's resumed turn-start gap is ACPX's per-turn
process generation, not the provider).

## Verification

- `server`: `native-lifecycle.test.ts` (new default cases: local Codex
and OpenCode warm, Claude, remote, unknown target, unmeasured harness,
managed Claude, admitted per-turn session, explicit choices, non-native
adapter), `agent-runner-selection.test.ts`, `runtime-selection.test.ts`
(335 pass).
- `packages/db`: `native-warm-follow-up-default-migration.test.ts` on
embedded Postgres. Default agents are cleared, the explicit edit is
kept, other harnesses and legacy adapters are untouched, audit rows are
written once, and a rerun is a no-op. Without the explicit-edit filter
the test fails. `check:migrations` passes.
- `codex-local` `build-config.test.ts` (65), `ui`
`config-fields.test.tsx` (40), restart-chaos unit tests (134), `tsc
--noEmit` for `server`.
- `adapter-utils` `paperclip-runner-lifecycle-default.test.ts`:
configuration writes and adapter conversion store no lifecycle for
Codex, OpenCode and Claude, keep `per_turn` for the others, and preserve
explicit choices. It fails without the fix.
- End-to-end default check on this branch (`ttft-baseline.ts --lifecycle
default`, codex and opencode, 2 samples): the agents read back with no
stored lifecycle, and every follow-up reused the runner and provider
session (no `runner.process.launch`). Follow-up TTFT was 3.6–4.8 s. This
check found the per-write `per_turn` injection fixed here.
- Restart chaos (codex and opencode, A1/B1/B5, K1/K2/K6, seed 4242), 8/8
PASS each with no open signatures: forced warm, forced per_turn, and
`--lifecycle default` on this branch (agents created without a
lifecycle).
- `pnpm verify` selects broader CI (harness config is a global input),
so required CI supplies the broad coverage.

## Risks

- Behavior change: local Codex and OpenCode agents keep a runner and
provider process for up to 5 minutes after a run. Instance sleep waits
for that idle window. The process is reaped by the idle timer, by
graceful shutdown, or by the #19879 reconnect grace if its controller
dies.
- Migration: agents whose "Turn by turn" was chosen at creation become
Automatic. The activity entry records the old value; choosing "Turn by
turn" restores it.
- Previous-release story (`rules/upgrade-safe-run-state.mdc`): a task
session keeps the lifecycle policy it was admitted with, so sessions
saved before this change stay `per_turn`. New sessions get the default.
No run, checkpoint or launch state changes shape.

> For core feature work, check [`ROADMAP.md`](ROADMAP.md) first and
discuss it in `#dev` before opening the PR. Feature PRs that overlap
with planned core work may need to be redirected — check the roadmap
first. See `CONTRIBUTING.md`.

## Model Used

- Anthropic Claude Opus 5.5 (`claude-opus-5-5`) in Claude Code, with
tool use (shell, file edit, test execution).

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links (only public GitHub `#NNN` / `github.com/paperclipai/paperclip`
URLs)
- [x] My branch name describes the change (e.g. `docs/...`, `fix/...`)
and contains no internal Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [ ] All Paperclip CI gates are green
- [ ] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-11-07 14:37:36 -06:00
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