Implement docs/monorail tasks serially in one session — drive rail-tdd at agreed seams, then commit.
Ask which rail skill or flow fits. Router over the rail pack.
Configure a repo for rail skills — all docs under docs/monorail/ (work tracker + domain). Run once per repo before other rail engineering skills.
Align on a plan or design — light grilling with domain docs by default; map mode for foggy multi-session efforts. Light mode writes docs/monorail/<slug>/align.md then auto-continues the planning chain (spec → slice).
Break an existing docs/monorail/<feature>/spec.md into tracer-bullet tasks under tasks/, each with Blocked by edges. Ends the planning chain — next step is user-triggered rail-build (same-session serial run).
Test-driven development with red-green-refactor. Use when building a behaviour test-first, fixing a bug with a regression test, or when rail-build needs TDD at an agreed seam.
Synthesize durable align/map sources (and current conversation) into docs/monorail/<feature>/spec.md, then auto-continue to rail-slice. Refuse empty context — do not invent a thin spec.
Compact the current conversation into a pass document for a fresh agent session.