3.18.1

PHP SDK 3.18.1 fixes aggregate completion planning for large workflow fan-outs. Servers advertising limits.max_workflow_task_completion_bytes supply the completion-body budget; ordinary endpoint and per-value limits remain in force. Older producers retain the conservative fallback.

On qualified native Server 3.9.1, the installed candidate completes 300 × 10KB activities without external storage. A 60 × 450KB completion is submitted once and receives the typed structural refusal, with zero partial activities; the same Worker then completes fresh work. Continuation command arguments remain inline under their existing authority.

The manual and API guidance distinguish admission-time pending updates from GET-by-ID reads. Retained reads require update_outcome_reads (native 3.6+), preserve the stable update ID, and may have an unknown original request key. Completed null remains distinct from pending, and reads do not resubmit the update.

GitHub and Composer distributions now omit internal CI tooling and Git metadata. Runtime code, examples, resources, configuration and public contracts are retained.

Source/package review and protected PHP 8.3.36 candidate acceptance passed on the exact native 3.9.1 tuple. Final Packagist/registry-only acceptance and stable manual/API publication are recorded on #411.