casefile-implement

name	casefile-implement
description	Use to implement approved Casefile tickets through a human-selected serial, look-ahead, or bounded pipeline strategy with exclusive writes and recorded review.

Casefile Implement

Require the accepted dependency-safe plan. Present the compatible implementation strategies, recommend one from ticket independence and runtime capabilities, and wait for explicit selection:

• Ticket batch for serial implementation and review without speculative next-ticket work.
• Ticket batch with look-ahead for serial implementation with one read-only preflight of the next accepted ticket.
• Pipeline for bounded look-ahead and overlap of one independent next ticket with review.

Persist and validate the exact selected matrix before delegation. The root owns scope, dependency order, exclusive write ownership, acceptance, correction routing, and synthesis. Assign overlapping mutations to one writer. Writers return an immutable commit per ticket and focused evidence. Apply every declared review stage. Before routing a finding, classify it as a correction, contention, or follow-up. Reviewers propose a class with evidence; the root has final classification authority:

• A correction is an explicit violation of the accepted contract and returns to the same writer in dependency order.
• A contention would introduce new architecture, durable state, a dependency, a failure guarantee, a compatibility promise, public behavior, or a material path expansion. The same semantic concern surviving one correction is also a contention.
• A follow-up is optional hardening that does not block acceptance.

Do not route a contention to a writer as though it were accepted scope. Stop batch work or drain a pipeline to serial state, present the evidence and concrete choice to the human, and resume mutation only after the human rejects the expansion or amends the governing decision or ticket. Complete a ticket only after the recorded flow accepts it. See the brief correction-escalation case study.

For Codex, when this implementation entry first persists its selected implementation matrix and no writer binding exists, run the installed scripts/resolve-writer-binding.py offer against the active Codex home. Present every returned model/effort pair, identify Sol/high as the recommendation, and require an explicit exact choice. If the offer marks Sol/high unavailable, say so and present every remaining valid pair without recommending an unselectable pair. Do not infer a recommendation as consent. Run the resolver's select command only to materialize the confirmed typed binding request. Pass that request to casefile_preview_writer_binding, review its envelope, and apply its preview_id in the same MCP session. The explicit model/effort choice authorizes persistence. If offering, preview, or persistence fails, stop before ticket progress, source mutation, or delegation and surface the diagnostic. This selection gate is Codex-only; do not change Claude implementation. A historical Casefile whose selected implementation matrix already exists without a binding retains that matrix's writer default and does not receive a backfill.

For Codex, immediately before every implementation-writer spawn, first successfully transition the applicable ticket to canonical in_progress, then run the installed scripts/resolve-writer-binding.py resolve with the planning root, active investigation, exact selected implementation strategy ID, and exact ticket ID. The resolver independently requires that current progress before returning a spawn. This applies equally to the first ticket, later batches, pipeline overlap, resume, and every correction round. Delegate with exactly the returned spawn object: V1 returns a named agent type; V2 returns a model-free role plus explicit model, reasoning, and bounded history override. Never reuse an earlier resolution without revalidation.

If resolution says the persisted or matrix-derived pair is invalid or unavailable, stop before delegation and before any planning/source mutation. Run offer, present its complete current list, state when Sol/high is unavailable, and request a new explicit selection. Replace the binding with select; canonical Store progress derives whether implementation or correction work is inactive and fails closed rather than accepting a caller assertion. Never substitute Sol/high or another pair silently. A missing binding in a historical Casefile is not an error: the resolver returns the selected matrix writer default after checking its current availability.

Keep per-ticket review and verification focused on that ticket's acceptance criteria, changed surfaces, and concrete findings. Reserve full workspace, package, and authenticated gates for the release candidate unless the ticket explicitly owns one of those surfaces.