skill-work-slicing

name	skill-work-slicing
description	Break a plan or spec into vertical slices that each declare what blocks them — use when work is agreed but not yet cut into fileable pieces

Host: Codex CLI — This skill was designed for Claude Code and adapted for Codex. Cross-reference commands use installed skill names in Codex rather than /octo:* slash commands. Use the active Codex shell and subagent tools. Do not claim a provider, model, or host subagent is available until the current session exposes it. For host tool equivalents, see skills/blocks/codex-host-adapter.md.

Work Slicing

Turn a plan, spec, or the conversation so far into a set of tickets. Each one is a vertical slice — a narrow but complete path through every layer — and each declares the tickets that block it.

This is the step between "we know what we are building" and "someone can pick up a piece of it". It does not decide anything: if decisions are still open, run skill-pressure-test first.

Adapted from to-tickets in mattpocock/skills (MIT), retargeted at this repo's trackers.

When To Use

• A plan or spec exists and needs cutting into fileable work.
• A tracking epic is too big to claim and needs children.
• Several people or sessions will work in parallel and need boundaries.

When Not To Use

• Decisions are still open. Slicing unresolved work produces tickets that get reopened. Use skill-pressure-test.
• The work fits one session. File one ticket, or none.
• You want parallel execution across agents right now, with worktrees and waves. That is /octo:parallel, which decomposes into work packages it then runs. This produces tracker state for humans and future sessions.

Inputs

The plan, spec, or conversation. Optionally a parent epic id to hang the slices under.

Workflow

1. Slice vertically

Each slice cuts a narrow but complete path through every layer it touches — schema, API, UI, tests. It is not a horizontal slice of one layer.

• A completed slice is demoable or verifiable on its own.
• Each is sized to fit one fresh context window.
• "Add the database columns" is horizontal and untestable alone. "Store and display the user's timezone, end to end" is vertical.

The first slice through a new area is the tracer bullet: thin, complete, and proves the path exists before anything is built out along it.

2. Declare what blocks what

For every slice, name the slices that must close first. Only real ordering constraints — not preference, not tidiness. Two slices that merely touch the same file are not blocked on each other; two where one cannot be verified until the other exists are.

Cycles mean the slicing is wrong, not that the tracker needs a workaround. Recut.

3. File them

This repo has two trackers and they are not interchangeable:

• bd (beads) is the system of record for work. bd create --parent=<id> makes a child; bd dep add <issue> <depends-on> makes a blocking edge; bd ready lists what is takeable — open, unblocked, and not in progress.
• GitHub issues are the public surface, via gh. Use them when the work is externally visible or a contributor needs to see it.

Put the detail in the ticket body, not in the parent. The parent indexes; the ticket holds.

4. When bd will not accept writes

bd is periodically write-blocked by pending Dolt schema migrations, and the repository rule is explicit: do not run the migration unless you are the single designated migrator, because migrating a second clone forks the schema irrecoverably.

When writes are blocked, do not pretend the work was filed and do not silently drop it. Instead:

1. Emit the ready-to-run bd create and bd dep add commands, complete and in dependency order, so they can be run unmodified once writes return.
2. Write them into the plan or a roadmap note under docs/roadmaps/, which is the practice this repo already follows.
3. Say plainly, in the output, that nothing was filed and why.

Provider Or Data Priority

1. The plan or spec as written.
2. The repository, to check whether a slice is already partly built.
3. The user, for sizing and priority. Do not invent priorities.

Stop Or Checkpoint Rules

• Stop and recut if any slice cannot be verified on its own.
• Stop if the blocking graph has a cycle.
• Stop before filing if more than about ten slices come out of one plan — that usually means the plan is really several, and filing them all buries the first.
• Confirm the slice list with the user before filing anything. Filing is visible to others and awkward to undo.

Output Contract

1. Slice list — title, one-line scope, and what it blocks on.
2. Order — which slices are takeable now, and which wait.
3. Filed or not filed — ids and links if filed; if not, the exact commands and the reason they were not run.
4. Left unsliced — anything in the plan too vague to cut, stated as such rather than forced into a ticket.

Verification

• Every slice is demoable or verifiable alone.
• No slice is a single layer's worth of work.
• The blocking graph is acyclic and every edge is a real constraint.
• If bd was unavailable, the emitted commands run unmodified — check the parent ids and the dependency order.