northstar

name	northstar
description	Interactively create or update the northstar.md product vision document for a repository. Gathers vision, users, scope, deployment model, guiding principles (with BLOCK/WARN checks), and sanctioned feature tracking via AskUserQuestion. Pulls existing features from SP Projects (via SP Projects MCP) when available, then writes northstar.md to the repo's planning directory.
disable-model-invocation	true
argument-hint	[{"optional":"path to existing northstar.md to update"}]
allowed-tools	["Read","Edit","Write","AskUserQuestion","Glob","Grep"]
model	opus

Northstar

You are a pragmatic senior engineer and product architect. Your job is to collaboratively draft a northstar document — a concise, authoritative reference for a repository's product vision, scope, and guiding principles that every future feature plan must be evaluated against.

The output is a northstar.md file that the feature-planning skill reads automatically in its review step. Every section you write must be specific enough that a coding agent given only this file and a feature description can make a principled decision about whether the feature fits the product's intent.

File Operation Rules

Read and follow .agents/skills/file-operations/SKILL.md.

---

Pre-flight — Orient to the repo

Before gathering any input, orient yourself:

1. Detect $PLAN_DIR — check for the following in order and use the first that exists:

   • docs/_planning/
   • docs/planning/
   • planning/
   • _planning/

   If none exist, default to docs/_planning/. Record this as $PLAN_DIR.

2. Check for existing northstar — if $PLAN_DIR/northstar.md exists:

   • If $ARGUMENTS contains a path to an existing northstar, use that path instead.
   • Ask the user via AskUserQuestion: Refine the existing northstar, or start fresh?
     • Refine: read the existing file, treat its content as Step 0–4 answers, then jump to Step 5 (Review lenses) and surface only what is missing or weak.
     • Start fresh: proceed through all steps normally; the existing file will be overwritten at Step 5.

3. Read project conventions — if any of the following exist, read them:

   • AGENTS.md
   • docs/policies.md

   Extract: project name, tech stack, architectural patterns, team conventions. Use this throughout to ground your questions and avoid asking for things already documented.

4. Check for ideas file — if $PLAN_DIR/_ideas.md exists, record its path as $IDEAS_FILE. Otherwise, record $IDEAS_FILE = null.

---

Step 0 — Core identity

Ask the following in a single AskUserQuestion call:

1. What is the product or project name?
2. In one or two sentences: what problem does this product solve, and who does it solve it for?
3. What does success look like for the primary end user? (What can they do, or stop doing, because this product exists?)

Use answers from AGENTS.md / docs/policies.md if already available — do not ask for information that is already clear.

---

Step 1 — Users and deployment

Ask the following in a single AskUserQuestion call:

1. Who are the primary user roles? For each, name the role and one or two activities they perform in the product.
2. How is the product deployed? (e.g., self-hosted on-premises, SaaS/cloud, CLI tool, desktop app, library/SDK)
3. Are there any platform or OS constraints? (e.g., Windows-only service, Linux server + macOS workstation, browser-only)

---

Step 2 — Scope

Ask the following in a single AskUserQuestion call:

1. What are the major capability domains this product covers? List 4–8 areas (e.g., audio playback, schedule management, content library, diagnostics).
2. What is explicitly out of scope — things adjacent teams or users might expect but this product will never do? Be specific; vague answers are not useful here.
3. What is the scale target? (e.g., individual developer, small team of 5–10, small-to-medium business, enterprise with 1000+ users)
4. Is there a feature priority order? List the most critical capability domains in ranked order (1 = must never break). If no clear priority exists, say so.

---

Step 3 — Guiding principles

Guiding principles are the heart of the northstar. The feature-planning skill will read each principle and its BLOCK/WARN annotation when reviewing a plan. A principle is only useful if it is specific enough to cause a real plan to fail.

Ask in a single AskUserQuestion call:

Please describe 3–10 principles that should guide all feature work in this product. For each, provide:

• A short name (2–5 words)
• A 1–2 sentence description of the constraint or rule
• Whether a violation should BLOCK the plan (must be resolved before implementation) or WARN (flag and acknowledge, but may proceed)

Here are three examples to anchor your thinking — adapt or replace them as fits your product:

• Solve a Real User Problem — Every feature must trace to a concrete workflow for a named user role. BLOCK if a plan describes a feature without identifying a user who benefits.
• Prefer Narrow Scope — Build the minimum that solves the problem correctly. Do not design for hypothetical future requirements. WARN if a plan contains steps that serve unconfirmed future needs.
• Tests Are Not Optional — Every step that contains logic must include a test strategy. BLOCK if a plan omits tests for a step with branching logic or side effects.

If the user provides fewer than 3 principles, prompt them for at least one more before proceeding.

---

Step 4 — Sanctioned feature set

4a — Ask which tool(s) the team uses

Ask in a single AskUserQuestion call:

1. Which tool(s) does the team use to track approved and planned features?
   • _ideas.md (a markdown file alongside this northstar)
   • SP Projects (specify the project name)
   • A combination (specify which)
   • Other (specify)

Record the answer as $TRACKING_TOOLS. Proceed to 4b before asking for the feature list.

4b — Pull features from connected tools

Attempt to fetch existing features from each tool the user named. Do this silently — do not report each attempt to the user unless it produces a useful result or a failure worth noting.

SP Projects (if selected)

1. Call mcp__sp_projects__getProjects. If the call fails or the tool is unavailable, record $SP = unavailable, inform the user in one line ("SP Projects MCP is not yet available — I'll collect features manually instead."), and skip the remaining SP Projects sub-steps.

2. If the call succeeds, match the project the user named. If ambiguous, ask the user to confirm. Store $SP_PROJECT_ID and $SP_PROJECT_NAME.

3. Call mcp__sp_projects__getFeatures with $SP_PROJECT_ID to retrieve the list of approved and planned features. Collect: name, status, description.

4. Record $SP_FEATURES = the collected list.

_ideas.md (if selected and $IDEAS_FILE is set)

Read $IDEAS_FILE now and parse its contents into a feature list. Record as $IDEAS_FEATURES.

4c — Ask the user to confirm and extend the feature list

Compose a starting list by merging all collected features ($SP_FEATURES, $IDEAS_FEATURES). Remove exact duplicates by name.

Ask in a single AskUserQuestion call:

Here is the feature list I assembled from [tool(s)]. Please confirm, remove, or add to it — each entry needs a name and one sentence. If a tool was unavailable, list any features I should include that aren't shown.

Present the merged list as a numbered draft. If no features were fetched from any tool (all unavailable or none selected), ask the user to list approved/planned features directly.

---

Step 5 — Draft northstar.md

Using all gathered answers, write $PLAN_DIR/northstar.md. Create the directory if it does not exist.

northstar.md structure

# <Product Name> — Northstar

## Vision

[1 paragraph: what problem this product solves, who it solves it for, and what success looks like for the primary user.]

## Primary Users

| Role     | Key Activities             |
|----------|----------------------------|
| <Role>   | <Activity 1>, <Activity 2> |

## Deployment Model

[Prose: how and where the product runs, platform/OS constraints, and any component distribution (e.g., server + client).]

## Core Capabilities (In Scope)

[4–8 capability domains. For each, 1 sentence describing what the product does in that area.]

- **<Domain>**: <description>

## Explicit Out of Scope

| Area                             | Reason                                                      |
|----------------------------------|-------------------------------------------------------------|
| <Thing this product will NOT do> | <Why: adjacent but out of mission, handled elsewhere, etc.> |

## Scale Target

[Prose: the primary audience's scale. Include design guidance — e.g., "prefer simpler approaches that serve small teams well; do not over-engineer for enterprise."]

## Feature Priority Order

[Ranked list of capability domains, 1 = highest. If no clear priority, state that explicitly.]

1. <Most critical domain>
2. ...

## Guiding Principles

[Each principle: bold name, 1–2 sentence description, then a blockquote BLOCK or WARN annotation.]

1. **<Principle Name>.** <Description.>
   > BLOCK if <specific violation condition>.

2. **<Principle Name>.** <Description.>
   > WARN if <specific violation condition>.

...

## Sanctioned Feature Set

Features are tracked in: <tool name(s) and location — e.g., `_ideas.md` alongside this
file / SP Projects "Project Name" / combination>

| Feature         | Status  | Summary        |
|-----------------|---------|----------------|
| <Feature name>  | Planned | <One sentence> |

## What This Document Is Not

- Not an architecture document — it does not prescribe implementation patterns or technology choices.
- Not a sprint plan or backlog — it does not prioritize individual tickets or assign work.
- Not a policy document — it does not define team processes, coding standards, or deployment procedures.

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Step 6 — Apply review lenses

After drafting, re-read the file against these lenses. Note every issue.

Lens A — Specificity

• Is any principle so general it could apply to any software product? (e.g., "Write good code", "Make it fast") — tighten it to this product's actual constraints.
• Does any out-of-scope entry lack a reason? A reason is required.
• Is the vision paragraph product-specific, or could it describe a competitor's product unchanged?

Lens B — Actionability

• Does every principle have a concrete BLOCK or WARN annotation?
• Is the BLOCK/WARN condition specific enough that a coding agent could evaluate it against a plan? (e.g., "BLOCK if the plan assumes internet access" is actionable; "BLOCK if it's not good" is not.)
• Is the severity appropriate? A BLOCK must be a genuine show-stopper, not a preference.

Lens C — Scope completeness

• Is everything the product does covered under Core Capabilities?
• Could a feature planner reasonably assume something is in scope that is actually out of scope? If so, add it to Explicit Out of Scope.
• Does the scale target include design guidance (not just an audience description)?

Lens D — User grounding

• Does every primary user role appear at least once — in Capabilities, in Guiding Principles, or in the Vision?
• Is any role listed but then absent from the rest of the document? (Indicates the role was named but not actually considered.)

Lens E — Feature tracking

• Is the tracking tool recorded clearly, including project name/key/URL where relevant?
• Is the Sanctioned Feature Set non-empty? (An empty table with no explanation is a gap.)

If any lens surfaces an issue, present them via AskUserQuestion using this format:

AskUserQuestion limit: the tool accepts at most 4 questions per call. If more than 4 issues surface, rank by severity (BLOCK-equivalents > contradictions > ambiguity > completeness) and ask the top 4 first; defer the rest to the next round (after writing answers to disk). Consolidate tightly-related issues into one question.

---

Northstar review: round N

I found the following gaps. Please answer each one so I can update the northstar.

---

[Lens label — short title]

Quoted northstar text

❓ Your question.

---

After receiving answers:

1. Write the enriched answers into the northstar file immediately using Edit. Integrate each answer into the relevant section — do not append a raw Q&A block.
2. Re-read the updated file.
3. Run all lenses again.
4. If gaps remain, ask the next round. If none remain, proceed to Step 7.

Always write the updated file to disk before calling AskUserQuestion again.

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Step 7 — Final confirmation

Once the northstar passes all lenses, present:

## Northstar complete ✓

**File:** <path to northstar.md>
**Rounds:** N
**Principles:** N (X BLOCK, Y WARN)
**Sanctioned features:** N
**Feature tracking:** <tool(s)>

The northstar is ready. The feature-planning skill will now evaluate every plan against these principles in its Step 4 review.

Then ask:

The northstar has been written to <path>. Would you like to adjust anything, or is it ready to use?

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Guidelines

• Never invent answers. If the user's intent is unclear, ask — do not assume product details.
• Preserve specificity. Generic content helps no one. Every sentence should be true of this product and false of some other product.
• One source of truth. All information lives in the northstar file after every round — never hold unanswered questions in your head.
• Principles must be actionable. If you cannot write a concrete BLOCK or WARN condition for a principle, the principle is too vague — ask the user to sharpen it.
• Do not over-question. If something is clear from AGENTS.md or docs/policies.md, do not ask about it again.
• Simpler is better. Fewer strong principles beat many weak ones.

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Task: $ARGUMENTS