brainstorm

The ideation organ. The stage before /envision: where a half-formed or blurry idea gets talked into enough shape that /envision can take it. One organ, two moods — discuss (explore a loose idea) and crystallize (pin a blurry one down) — they're the same conversation at different stages, so there's one verb.

[half-formed idea] → /brainstorm → shaped idea (.claude/ideas/<slug>.md) → /envision → /spec → …

The discipline: it must converge, not just chat. A /brainstorm that ends without a crystallized statement the user accepts was just conversation. The engineer wants the idea sharpened, not a transcript.

Your first reply

The first reply is short and has exactly this shape:

1. Play the idea back in two or three sentences, in your words.
2. Ask one question. If the user hasn't said why they want this, ask why, openly and in their terms, with no options and no example answers.
3. Say in one line what the answer will change.

Example, for "/brainstorm a tool that tracks my reading":

You want something that keeps a record of what you read, so it doesn't vanish once you close the tab or book. What made you want this now? Knowing whether it's about remembering, finding things again or reading more decides what the tool keeps.

No numbered question lists, no option menus, no draft name or note in the first reply. If the idea is already sharp and the why is known, skip the question and propose the crystallized note instead.

When to run

• /brainstorm [slug] — start (or resume) shaping an idea.
• Natural language: "help me shape this idea", "I have a vague idea for X", "let's think this through", "crystallize this", "put a name and edges on this".
• Do not auto-fire. Mode A. Not for an idea that's already shaped (go straight to /envision or /spec), not for a one-line task (just do it).

Procedure

1. Resolve slug + read any prior note

• Slug given → use it. Omitted → derive a short kebab slug from the idea once it has a name, or ask.
• If .claude/ideas/<slug>.md exists, read it and resume from where it left off (this is the cross-session-gap recovery the persisted note buys).

2. Look before you ask

If the idea points at something (a project, files, notes, an earlier conversation), read it before your first reply. Never ask what it already answers, and don't reopen what the user already decided.

3. Discuss — explore, but steer toward shape

Talk the idea through. Every few turns, pull toward the five things a shaped idea needs (below). Do not drift into spec-level detail (functions, files, schemas): that's /spec's job. When the user starts there, redirect: "that's implementation — let's pin what this is first."

After that, one question per message. Ask only when the answer would change the name, the edges or the end goal and nothing already answers it; otherwise state your call as a proposal the user can correct. Once you know the why, when a choice has options you can name, sketch each with its trade-off and say which you'd pick.

The five things to converge on:

1. Name — what to call it.
2. Description — one paragraph: what it is, who it's for, the one-sentence success criterion.
3. Edges — what's in and, more importantly, what's explicitly out (the non-goals that keep it from absorbing scope).
4. End goal — what "done / working" looks like.
5. Open edges — the questions still genuinely unresolved (carried forward, not forced).

4. Crystallize — propose the shaped idea

When the five are roughly there (or the user says "pin it"), propose the crystallized note for accept / edit / reject:

---
slug: <slug>
status: shaped
created: YYYY-MM-DD
description: <one-line>
---

# Idea — <name>

**What it is:** <one paragraph — what, who for, success in a sentence>
**In:** <comma-separated — what this is>
**Out (non-goals):** <comma-separated — what it deliberately isn't>
**End goal:** <what done/working looks like>
**Open edges:** <unresolved questions, or "none yet">

Don't force premature precision — status: shaping is allowed if it genuinely isn't crystallized yet, but say so and name what's still blurry.

5. Write + hand off

On accept: write .claude/ideas/<slug>.md, update .claude/ideas/INDEX.md (one row per idea: slug / status / created / one-line). Then point downstream:

Shaped <name> → .claude/ideas/<slug>.md. When you're ready to partition it into modules, run /envision <slug> — it'll pick up this note as the starting intent.

On edit → revise the draft, re-propose. On reject → discard, write nothing.

What brainstorm does NOT do

• Does not partition into modules / draw the module map. That's /envision. brainstorm stops at the shaped idea; envision turns it into a structure.
• Does not produce spec-level detail (functions, files, data shapes, APIs). Redirect to /spec, downstream.
• Does not just chat. It must converge to a crystallized note the user accepts, or it produced nothing.
• Does not auto-fire, and does not silently write — the note is proposed first.
• Does not implement anything.

Relationship to other organs

• envision — the immediate downstream. brainstorm's .claude/ideas/<slug>.md becomes /envision <slug>'s starting intent.
• improve-prompt — a sibling interview-to-converge organ, but for prompts, not project ideas. Different corpus, same converge-don't-ramble discipline.
• spec — two hops downstream (brainstorm → envision → spec). brainstorm shapes the idea; spec pins one module's requirements.