Two configurable numbers per project. `maxSpawnedAgentsPerParent` (5)
and `maxSpawnedAgentsGlobal` (20) were a **third and fourth** limiter
with private budgets invisible to both.
## This closes a hole, not just knobs
A spawned child **is** an agent and gets **its own git worktree**
(branched from the parent’s — the tool’s own description says so), but
children were counted by **neither** capacity gate. A fan-out could put
up to 20 extra worktrees on disk while the scheduler believed the
project was at its configured limit. The operator’s two numbers were
simply wrong about what was running.
## The old caps also measured the wrong thing
`totalSpawnedCount` decrements on child cleanup, but the per-parent
**set** is cleared only when the **parent task** ends. So
`maxSpawnedAgentsPerParent` throttled *cumulative* spawns across a
task’s life rather than *concurrent* ones — a long-running task could
exhaust its budget with five children that had all long since finished,
and the operator had no way to see why.
## Fix
`fn_spawn_agent` gates on the same project agent count every other lane
uses (`computeTopLevelConcurrencyClaimedFromStore`) plus live children.
One number, one answer, no private budget that can disagree with the
board.
The refusal names **Max Concurrent Tasks** — a control the operator
actually has. The old messages pointed at settings that no longer exist,
which is worse than no message: it sends someone hunting for a knob that
is not there.
## Verification
**Revert-proof, measured:** restoring the private budgets turns **3 of
the 4** new cases red — a project at 1/1 could still spawn, which is
precisely the hole. `executor.ts` restored byte-identical.
`pnpm lint` clean · core + engine `tsc` clean · `pnpm test:gate` green
(414 + 10 + 71) · new suite 4/4 · `settings-default-descriptions` 4/4.
There was no spawn-capacity test before this; the file is new.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
* **New Features**
* Spawned agents now count toward the project’s **Max Concurrent Tasks**
capacity.
* Agent spawning is blocked when capacity is reached, including
concurrent spawn attempts.
* **Bug Fixes**
* Prevented over-allocation during simultaneous agent spawns.
* Restored available capacity when agent creation fails.
* **Changes**
* Removed separate per-parent and global spawned-agent limits.
* Updated settings to reflect the revised capacity controls.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
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Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
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