prep

name	prep
description	Bootstrap work on a Linear ticket — fetch ticket, create branch, mark in-progress, explore codebase, and plan implementation. Use when user says "prep", "start ticket", "begin work", "pick up ticket", or provides a Linear ticket ID to start working on.
user-invocable	true

Prep

Bootstrap a Linear ticket for development: fetch ticket, create branch, mark in-progress, explore codebase, and produce an implementation plan. No code changes are made.

Step 1: Resolve the Linear Ticket

A. Get the ticket ID.

• The ticket ID is a required argument. The user must provide it when invoking the skill (e.g., /prep TRA-573).
• If no argument was provided, respond with a friendly message and STOP — do not continue:

  No ticket ID provided. Run /prep with your Linear ticket ID — e.g., /prep TRA-573 — and I'll handle the rest.

B. Fetch the ticket.

• Call Linear MCP to fetch the ticket by its ID. Retrieve its title, description, status, priority, and git branch name.
• On success: log Found <ticket-id>: <title> and continue.
• On failure (bad ID, MCP unavailable, auth error): report the specific error and STOP. Tell the user to re-run with a valid ticket ID (e.g., /prep TRA-573). Do not prompt or retry.

Step 2: Create Git Branch

A. Ask for base branch.

• Use the AskUserQuestion tool to ask:

  Base branch? Options:

  1. main (press Enter)
  2. Current branch (<show current branch name here>)
  3. Type a specific branch name

• Option 1 (Enter/main): use origin/main.
• Option 2 (current): use origin/<current-branch>. If current branch has no remote tracking, use the local branch as base.
• Option 3 (custom): use origin/<provided-name>. Verify it exists with git rev-parse --verify origin/<branch>. If not found, try the local ref. If neither exists, report the error and ask again.

B. Create and checkout the branch.

1. Run git fetch origin to ensure the latest refs.
2. Use the git branch name from the Linear ticket (retrieved in Step 1) as the branch name. Do NOT generate your own branch name.
3. Run git checkout -b <branch-name> <base-ref>.
4. Log: Created branch: <branch-name> from <base>

Step 3: Mark Ticket In Progress

• Update the ticket status to "In Progress" via Linear MCP.
• Log: <ticket-id> moved to In Progress

Step 4: Explore & Understand

Now dig into the ticket and codebase. Do NOT write any code or edit any files.

1. Parse the ticket — extract what needs to change, the expected outcome, and any acceptance criteria or constraints from the description.
2. Explore the codebase — use the Explore agent or Grep/Glob/Read tools to find:
   • Relevant files, components, schemas, queries, or utilities
   • Existing patterns that relate to the work
   • Dependencies or upstream/downstream impacts
3. Identify key files — list the files that will likely need changes and why.

Step 5: Draft Implementation Plan

Present a structured plan to the user:

## Implementation Plan — <ticket-id>: <title>

### Understanding
[1-2 sentence summary of what the ticket asks for]

### Approach
[High-level strategy for the implementation]

### Steps
1. [Concrete step with file paths]
2. [Next step...]
...

### Files to Modify
- `path/to/file.tsx` — reason
- `path/to/other.ts` — reason

### Files to Create (if any)
- `path/to/new-file.tsx` — purpose

### Risks / Open Questions
- [Anything unclear or worth flagging]

After presenting, ask: "Want me to proceed with this plan, adjust anything, or stop here?"

CRITICAL: Do NOT write code, create files, or make any changes. This skill is planning-only.