## Thinking Path
> - Paperclip is the open source app people use to manage AI agents for
work
> - CI runs a Canary Dry Run job that exercises `release.sh`, which
builds the standalone sandbox-provider packages for publish
> - That step (`scripts/build-standalone-public-packages.mjs`) built the
7 provider plugins serially — each doing `rm -rf dist && tsc` — making
it the dominant cost (~49s) inside the slowest PR check (~4.9m wall)
after the general-server lane was already sharded
> - The packages are independent (their own `node_modules` via
`--ignore-workspace`, their own `dist`), so the serial build is pure
latency with no correctness benefit
> - This pull request builds them with a bounded-concurrency pool sized
to the runner CPU count (overridable via
`STANDALONE_BUILD_CONCURRENCY`), buffering each package's output and
flushing it as one block so parallel logs stay readable, and aggregating
failures by original index
> - The benefit is a faster Canary Dry Run / PR feedback loop without
changing what gets built or published
## Linked Issues or Issue Description
No public GitHub issue exists. Inline feature/perf description:
### Problem or motivation
`build-standalone-public-packages.mjs` builds standalone provider
packages serially, making it the largest single cost inside the slowest
PR check.
### Proposed solution
Run independent per-package builds through a bounded-concurrency worker
pool sized to runner CPU count, with an env override and readable
buffered logs.
### Alternatives considered
Keep the serial build for simpler logs, but that preserves the avoidable
CI latency.
### Roadmap alignment
This is CI maintenance and does not overlap planned core roadmap work.
## What Changed
- `scripts/build-standalone-public-packages.mjs`: replaced the serial
per-package build loop with a bounded-concurrency pool (default = runner
CPU count, override via `STANDALONE_BUILD_CONCURRENCY`); per-package
stdout/stderr is buffered and flushed as a single block; failures are
aggregated by original package index so one failure neither aborts the
others mid-flight nor obscures which package broke.
- `scripts/__tests__/build-standalone-concurrency.test.mjs`: new
`node:test` unit suite covering the pool (limit respected, all items
run, ordered failure aggregation, env-override resolution).
- `.github/workflows/pr.yml`: wired the new unit test into the policy
job.
## Verification
- `node --test
./scripts/__tests__/build-standalone-concurrency.test.mjs` → 6/6 pass
- `node ./scripts/release-package-map.mjs check` → OK (29 enabled for CI
publish)
- `git diff --check origin/master..HEAD` → clean
## Risks
- Low risk. Build inputs/outputs are unchanged; only scheduling differs.
The concurrency is bounded by CPU count and overridable; output is
buffered per package so logs remain attributable. If a package fails,
all failures are still reported with their package index.
## Model Used
- Claude (Anthropic), `claude-opus-4-8`, extended thinking with tool
use.
## 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 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
- [ ] 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
---------
Co-authored-by: Paperclip <noreply@paperclip.ing>
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