Before proceeding, verify you are in a scaffolded Cribl app folder. If you are not, stop and tell the user: "You must run this skill from within a scaffolded Cribl app folder."

Instructions

You are implementing a Cribl app based on an APP_BRIEF.md file. Use Capra UI by default for all components. Before starting, review ./references/cribl-apps-guidance.md to avoid common pitfalls with KV store, state management, error handling, and other Cribl-specific patterns.

Follow this workflow:

1. Validate Prerequisites

Check that APP_BRIEF.md exists in the working directory
If missing, error with: "APP_BRIEF.md not found. Run /app-brief first."
Create /executions directory if it doesn't exist

2. Load & Compare Versions

Read the current APP_BRIEF.md
Find the most recent APP_BRIEF_*.md in /executions (sort by timestamp in filename)
If no prior execution: treat entire current brief as new work (delta = all of it)
If prior execution exists: diff the two to identify:
- New sections/requirements
- Modified sections/requirements
- Sections removed (note: don't undo these)

3. Parse Delta into Action Items

Extract specific implementation tasks from the delta
For each task, create one clear, actionable line describing what will be done
Example lines:
- "Create new component: UserInput"
- "Update API endpoint /search to support filtering"
- "Add test coverage for AuthService"

4. Dry-Run Mode (if `--dry-run` flag provided)

Print header: "=== DRY RUN: Planned Changes ==="
Print each action item as one line (no descriptions, just the action)
Print footer: "=== End Dry Run ==="

Example output:

=== DRY RUN: Planned Changes ===
Create new component: UserInput
Update API endpoint /search to support filtering
Add test coverage for AuthService
=== End Dry Run ===

5. Implementation Mode (normal execution, no `--dry-run`)

Execute the delta: create files, modify code, update configs as needed
Read the app id from APP_DEFINITION.md (under "## App ID" section)
Update the "name" field in package.json to match the app id
Remove all linter errors, run npm run lint

6. Archive This Run

Copy current APP_BRIEF.md to /executions/APP_BRIEF_[ISO8601-timestamp].md
Use format: APP_BRIEF_2026-07-31T14-30-45Z.md (ISO 8601, with colons replaced by hyphens for filesystem compatibility)
This becomes the baseline for the next run

7. Confirm Package.json Update

Verify that package.json's "name" field now matches the app id from APP_DEFINITION.md

Key Principles

Source of truth: Current APP_BRIEF.md always wins
Idempotency: Skill can run repeatedly; each run only touches what changed
Stateless between runs: /executions folder is the only state persistence

app-implement

Pre-flight Check