brainstorm

Brainstorming — Discovery-Time Ideation

PURPOSE: Help the user think through ideas, compare options, and iterate on an unclear problem. Brainstorm produces understanding, not artifacts. Invoke it whenever you need to explore the solution space — at the start of a task, mid-implementation when scope is unclear, or any time the user says "let's think about this."

NOT A PIPELINE STAGE: Brainstorm is not a required step before plan. It hangs off DISCOVER as an optional tool, the same way debug does. The user invokes it on demand; kickoff may offer it during discovery if the work type benefits from exploration.

CONFIGURATION: Reads jig.config.md for plans-directory (only if the user opts into saving a brainstorm doc).

When to Use

Invoke this skill when:

• Creating a new feature or component
• Adding functionality to existing code
• Modifying behavior that affects users or systems
• The user says "let's design", "how should we build", "I want to add..."
• kickoff offers this as a discovery-time tool during the DISCOVER stage

Do NOT use when:

• Fixing a bug with an obvious root cause (use debug)
• Running a chore or config change (skip to plan)
• You only need to create a PR (use pr-create directly)

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Checklist

Complete these steps in order:

1. Explore project context — check files, docs, recent commits
2. Offer visual companion (if topic involves visual questions) — its own message; see Visual Companion section
3. Ask clarifying questions — one at a time, understand purpose / constraints / success criteria
4. Propose 2-3 approaches — with trade-offs and your recommendation
5. Iterate — refine the approach with the user until they have clarity
6. Hand off — summarize what was decided in conversation; return control to the user or invoking skill. Do NOT auto-invoke plan. Do NOT write a design doc unless the user explicitly asks for one.

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Process Flow

flowchart TD
    A[Explore project context] --> B{Visual questions ahead?}
    B -->|yes| C[Offer Visual Companion<br/>own message, no other content]
    B -->|no| D[Ask clarifying questions<br/>one at a time]
    C --> D
    D --> E[Propose 2-3 approaches<br/>with trade-offs]
    E --> F[Iterate with user]
    F --> G{User has clarity?}
    G -->|no, keep exploring| D
    G -->|yes| H[Summarize decisions<br/>in conversation]
    H --> I((Return control))

The terminal state is returning control. Brainstorm produces understanding, not artifacts. Do NOT auto-invoke plan or any other implementation skill — the user decides what's next.

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The Process

Understanding the Idea

• Check the current project state first (files, docs, recent commits)
• Before asking detailed questions, assess scope: if the request describes multiple independent subsystems (e.g., "build a platform with chat, file storage, billing, and analytics"), flag this immediately. Do not spend questions refining details of a project that needs to be decomposed first.
• If the project is too large for a single spec, help the user decompose into sub-projects: what are the independent pieces, how do they relate, what order should they be built? Then brainstorm the first sub-project through the normal design flow. Each sub-project gets its own spec, plan, and implementation cycle.
• For appropriately-scoped projects, ask questions one at a time to refine the idea
• Prefer multiple choice questions when possible, but open-ended is fine too
• Only one question per message -- if a topic needs more exploration, break it into multiple questions
• Focus on understanding: purpose, constraints, success criteria

Exploring Approaches

• Propose 2-3 different approaches with trade-offs
• Present options conversationally with your recommendation and reasoning
• Lead with your recommended option and explain why
• Be specific about what each approach costs and gains

Presenting the Design

• Once you believe you understand what to build, present the design
• Scale each section to its complexity: a few sentences if straightforward, up to 200-300 words if nuanced
• Ask after each section whether it looks right so far
• Cover: architecture, components, data flow, error handling, testing approach
• Be ready to go back and clarify if something doesn't make sense

Design for Isolation and Clarity

• Break the system into smaller units that each have one clear purpose, communicate through well-defined interfaces, and can be understood and tested independently
• For each unit, you should be able to answer: what does it do, how do you use it, and what does it depend on?
• Can someone understand what a unit does without reading its internals? Can you change the internals without breaking consumers? If not, the boundaries need work.
• Smaller, well-bounded units are easier for AI agents to work with -- they reason better about code they can hold in context at once, and edits are more reliable when files are focused.

Working in Existing Codebases

• Explore the current structure before proposing changes. Follow existing patterns.
• Where existing code has problems that affect the work (e.g., a file that has grown too large, unclear boundaries, tangled responsibilities), include targeted improvements as part of the design.
• Do not propose unrelated refactoring. Stay focused on what serves the current goal.

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After Brainstorming

Brainstorm produces no required artifact. When the user has clarity, end the session by:

1. Summarizing the decisions — 3-5 bullets in conversation capturing the chosen approach and key trade-offs
2. Asking what's next — "Want to capture this as a PRD, jump to a plan, or sit with it?"

If the user wants a design doc for archival reasons, save to {plans-directory}/YYYY-MM-DD-<topic>-brainstorm.md (read plans-directory from jig.config.md, default docs/plans). This is opt-in, not default.

Do NOT auto-invoke plan or any other implementation skill. Brainstorm's job is to leave the user better-informed; the next move is theirs.

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Visual Companion

A browser-based companion for showing mockups, diagrams, and visual options during brainstorming. Available as a tool -- not a mode. Accepting the companion means it is available for questions that benefit from visual treatment; it does NOT mean every question goes through the browser.

Offering the companion: When you anticipate that upcoming questions will involve visual content (mockups, layouts, diagrams), offer it once for consent:

"Some of what we're working on might be easier to explain if I can show it to you in a web browser. I can put together mockups, diagrams, comparisons, and other visuals as we go. This feature is still new and can be token-intensive. Want to try it? (Requires opening a local URL)"

This offer MUST be its own message. Do not combine it with clarifying questions, context summaries, or any other content. Wait for the user's response before continuing. If they decline, proceed with text-only brainstorming.

Per-question decision: Even after the user accepts, decide FOR EACH QUESTION whether to use the browser or the terminal. The test: would the user understand this better by seeing it than reading it?

• Use the browser for content that IS visual -- mockups, wireframes, layout comparisons, architecture diagrams, side-by-side visual designs
• Use the terminal for content that is text -- requirements questions, conceptual choices, tradeoff lists, scope decisions

A question about a UI topic is not automatically a visual question. "What does personality mean in this context?" is a conceptual question -- use the terminal. "Which layout works better?" is a visual question -- use the browser.

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Key Principles

• One question at a time -- do not overwhelm with multiple questions
• Multiple choice preferred -- easier to answer than open-ended when possible
• YAGNI ruthlessly -- remove unnecessary features from all designs
• Explore alternatives -- always propose 2-3 approaches before settling
• Incremental validation -- present design, get approval before moving on
• Be flexible -- go back and clarify when something doesn't make sense

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Integration

Called by:

• Direct user invocation (/brainstorm)
• kickoff may offer it during DISCOVER for features / unclear scope

Terminal state:

• Return control to the user or invoking skill. No forced next step.

Related skills:

• prd — when ideas crystallize into requirements
• plan — when approach is clear and ready to decompose
• debug — sister discovery tool for understanding bugs

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Common Mistakes

Mistake	Consequence	Fix
Multiple questions per message	User overwhelmed, answers incomplete	One question at a time, always
Writing vague design sections	Ambiguous requirements lead to wrong implementation	Scale sections to complexity, be specific
Not decomposing large projects	Unmanageable scope, spec too broad	Flag multi-subsystem projects, decompose first
Auto-invoking plan after brainstorming	User loses control of the workflow	Brainstorm returns control. The user chooses what's next.