replan-slice

What It Does

replan-slice fires when an executor task reports blocker_discovered: true — meaning the existing slice plan cannot continue as written. A blocker is not a bug or a minor deviation; it is a plan-invalidating finding: a wrong API, a missing capability, an architectural mismatch, or a constraint discovered during execution that makes the remaining tasks fundamentally invalid. When this happens, rather than re-dispatching the failing task or abandoning the slice, the dispatcher replans everything that hasn’t been completed yet.

The replanner receives the full current slice state — the completed tasks (their summaries and [x] checkboxes), the incomplete tasks (their [ ] entries), the blocker task summary explaining what was discovered, and any user-captured thoughts that triggered or informed the replan. It reads all of this to understand exactly what the blocker is, then rewrites only the incomplete tasks to address it. Completed tasks are never modified — they are historical records.

The output is a two-part artifact: a REPLAN.md document explaining what changed and why, and an updated slice plan with the revised incomplete tasks. New task IDs continue from the highest existing ID to avoid renumbering conflicts. Once the replan is written, the dispatcher resumes execute-task dispatch from the first incomplete task in the updated plan.

Pipeline Position

This prompt fires only on demand — when an executor explicitly signals a blocker. Most slices complete without ever triggering a replan. When it does fire, it sits between execute-task and the continuation of execute-task, acting as a correction gate that ensures future task dispatches are based on a plan that reflects reality rather than a now-invalid original design.

Variables

Variable	Description	Required
sliceId	Current slice identifier being replanned	Yes
sliceTitle	Human-readable title of the slice being replanned	Yes
milestoneId	Current milestone identifier	Yes
workingDirectory	Absolute path to the project working directory	Yes
inlinedContext	Pre-assembled context block containing the current slice state and blocker information	Yes
captureContext	Content or path of the blocker capture that triggered this slice replan	Yes
replanPath	File path where the new replanned slice plan should be written	Yes
planPath	File path to the existing slice plan that needs to be replanned	Yes

Used By

• /gsd auto — dispatched only when an executor task signals blocker_discovered: true in its summary