Implement Prd

Reads a PRD, builds an execution plan, then implements it fully. No guessing: if something is ambiguous, stop and ask.

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Guiding Principles

• Plan before coding. Always produce and confirm the execution plan before writing a single line of code, unless user said not to.
• One question at a time. If the PRD is ambiguous, surface all blockers upfront in a single message — not one by one mid-implementation.
• Full implementation. Do not stub, scaffold, or leave TODOs unless the user explicitly asks. Every FR must be implemented.
• Stay faithful to the PRD. Do not add features, opinions, or improvements not specified. If you see a problem, flag it, don't silently deviate.

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Execution Instructions

Step 1 — Locate the PRD

If the user specified a file path, read it. If not, ask: > "Which PRD file should I implement? (e.g. docs/my-feature.md)" Do not proceed until you have the file.

Step 2 — Quickly Parse & Validate

Read the full PRD. Check for:

• Ambiguities — requirements that could be interpreted two or more ways
• Contradictions — two requirements that conflict
• Missing decisions — anything a build agent cannot reasonably default

If any blockers are found, list them all in a single message and wait for the user to resolve them before continuing. Format as:

Before I start, I need to clarify a few things:
1. FR-03 says X — should that mean A or B?
2. FR-07 and FR-11 conflict: X vs Y. Which takes precedence?

If the PRD is fully clear, proceed immediately.

Step 3 — Execution Plan

Produce a task list derived from the PRD's FRQs. Each task must:

• Map to one or more FR-XX identifiers
• Name the file(s) to be created or modified
• Be sequenced so dependencies come first

Format:

Execution Plan
1. [FR-01] Create `src/models/user.ts` — User data model and types
2. [FR-02, FR-03] Create `src/api/auth.ts` — Login and signup endpoints
3. [FR-04] Create `src/middleware/auth.ts` — JWT validation middleware
...

Present the plan and wait for the user to confirm ("looks good", "go ahead", etc.) before writing any code.

Step 4 — Implement

Execute the plan in order. For each task:

• Write complete, working code — no stubs, no TODOs
• Follow any tech stack, constraints, or conventions specified in the PRD
• If the PRD specifies NFRs (performance, security, etc.), apply them inline

After all tasks are done, give a brief completion summary listing what was created/modified.

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Ambiguity Rules

• Stop and ask for anything that changes behavior or architecture.
• Default silently only for trivially standard decisions (e.g. using 4-space indentation, hashing passwords with bcrypt, returning 404 for missing resources).
• Never skip a requirement. If something is unimplementable as written, flag it immediately.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: ca-lee-b
• Source: ca-lee-b/personal-skills
• License: MIT

Install and usage instructions live in the source repository linked above.