Problem It Solves
Closes gap: #168
Independent workflow steps (e.g., lint-agent and security-auditor reviewing the same PR) run sequentially today, doubling the time for steps that could run concurrently. There is no fan-out/fan-in mechanism.
Proposed Behavior
Step definitions in SKILL.md support a parallel group marker. Steps in the same group run concurrently; the engine fans out to all of them and waits for all to complete (or any to fail) before advancing:
| Step | Role | Parallel Group |
|------|------|----------------|
| 4 | lint-agent | review |
| 5 | security-auditor | review |
| 6 | reviewer | review |
| 7 | tester | — |
Steps 4, 5, and 6 run in parallel. The engine creates a state record for each parallel branch and waits for all branch handoffs to be written before advancing to step 7.
Human approval gates on parallel steps require all branches to pass before the gate clears. If one branch fails (e.g., security-auditor finds a blocking issue), the gate fails even if the other branches passed.
Dependencies
Complexity Estimate
Large — 6–8 files: engine fan-out/fan-in logic, state schema extension, gate evaluation across parallel branches, CLI display of parallel step status, tests
Problem It Solves
Closes gap: #168
Independent workflow steps (e.g., lint-agent and security-auditor reviewing the same PR) run sequentially today, doubling the time for steps that could run concurrently. There is no fan-out/fan-in mechanism.
Proposed Behavior
Step definitions in SKILL.md support a
parallelgroup marker. Steps in the same group run concurrently; the engine fans out to all of them and waits for all to complete (or any to fail) before advancing:Steps 4, 5, and 6 run in parallel. The engine creates a state record for each parallel branch and waits for all branch handoffs to be written before advancing to step 7.
Human approval gates on parallel steps require all branches to pass before the gate clears. If one branch fails (e.g., security-auditor finds a blocking issue), the gate fails even if the other branches passed.
Dependencies
Complexity Estimate
Large — 6–8 files: engine fan-out/fan-in logic, state schema extension, gate evaluation across parallel branches, CLI display of parallel step status, tests