---
prompt_version: 1
layer: slice
action: build
---

# Prompt: Build Slice Overview

Use the upstream specification, repository context, and Day Shift agent entrypoint to create or update a slice overview.

## Instructions

- Command placeholder: Expand `<day-shift-cli>` to the resolved session invocation. Use `day-shift` for installed/user mode after verification, and use `node dist/cli/index.js` in repository development mode when compiled `dist` output is current.
- Create missing canonical artifacts only for the selected layer. When revising an existing artifact, update it in place and do not create sibling, child, paired, or alternate artifacts unless the current user request explicitly asks for that creation step.
- Keep the overview focused on slice-level intent and boundaries.
- Do not include detailed task execution steps.
- Use the minimum number of phase candidates needed to fully implement the slice. Do not add phase candidates merely to turn inferred detail into extra prose.
- Split phase candidates only for meaningful implementation, sequencing, validation, rollback, ownership, risk, or readiness boundaries.
- In a standard generated slice overview, `## Phases` must declare at least one ordered phase slug with a short description. Before link materialization, use raw backticked slug bullets such as ``- `01-runtime-and-context`: establish shared runtime and repository context behavior.``. After link materialization, the same declaration may be a Markdown link bullet such as `- [01-runtime-and-context](phases/01-runtime-and-context/phase-overview.md): establish shared runtime and repository context behavior.`.
- Phase slugs declared in standard slice overviews must match `^\d{2}-[a-z0-9]+(?:-[a-z0-9]+)*$`, be unique, and appear in ascending order.
- Do not leave prose-only phase bullets or placeholder phase text such as `To be planned.`, `TBD`, `TODO`, or `Pending.` in saved standard slice overviews.
- Preserve existing user-authored content when updating.
- When revising an existing slice overview, always refresh status, planning depth, upstream traceability, and other front matter metadata so it reflects the current slice state rather than the original draft state.
- Label assumptions explicitly instead of silently inventing scope, sequence, or validation detail.
- Preserve traceability to the upstream spec and its registered source-spec reference without assuming that source lives at repository root.
- If the upstream spec is emergent work, preserve that emergent traceability rather than flattening it into an ordinary planned slice.
- When creating a new slice directory, ensure `decisions/` and `notes/` exist and are initialized with `.gitkeep`.
- After creating or revising the slice overview, run `<day-shift-cli> validation links-check --scope planning --artifact <slice-overview-path>` as read-only local trace-link evidence, then run `<day-shift-cli> link materialize --dry-run --artifact <slice-overview-path>` and use `<day-shift-cli> link materialize --write --artifact <slice-overview-path>` only when the dry-run reports safe selected-artifact body-reference changes. `<day-shift-cli> validation smoke --scope planning --artifact <slice-overview-path>` may be used to check the `declared-child-slugs` lane for standard child declaration syntax; that lane accepts both raw backticked slug bullets and materialized Markdown-link slug bullets. Treat validation findings as evidence only; treat link materialization as an explicit selected-artifact body-link write only, not as permission to mutate metadata or create downstream artifacts.
- Record known decisions, risks, validation strategy, and open questions.
- Stop and report instead of guessing when the selected artifact and upstream evidence conflict materially.
- Use standard planning unless the source clearly supports lightweight planning.
- For lightweight slice overviews, `## Phases` may instead explicitly state that phase artifacts are intentionally skipped and direct lightweight tasks are the next planning layer; do not require phase slug bullets when `planning_depth: lightweight`.
- Use repository-relative paths throughout the artifact.
- Preserve the canonical artifact-shape contract from `.day-shift/specs/06-templates-and-prompts/templates.md`: one visible H1, the required H2 section names in order, parser-safe `Open Questions` none-state, and no leaked scaffolding prose or unresolved placeholders in the saved artifact.

## Template Reference

Use `.day-shift/templates/slice-overview.md` as the artifact shape.

## Required Output

Create or update a slice overview artifact with the configured template sections and valid front matter, and initialize `decisions/.gitkeep` and `notes/.gitkeep` when the destination slice directory is new.
