ce:brainstorm

ce:brainstorm is a skill for Claude Code, Codex from marcusrbrown/systematic. It costs 106 tokens per session (3,625 once invoked), scanned A, original, MIT.

A collaborative brainstorming workflow for turning a feature idea into a requirements document. TDD means test-driven development; this workflow focuses on deciding what to build, not writing the code.

In plain words
What is it for?
Use it to explore a feature or improvement, resolve open product decisions, and produce a requirements document for a later implementation plan.
Why use it?
It helps clarify goals, alternatives, scope, and success criteria before implementation begins, reducing guesswork in later planning.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/marcusrbrown/systematic/ce-brainstorm
Any agent
npx skills add marcusrbrown/systematic --skill ce-brainstorm
Clone the repo
git clone --depth 1 https://github.com/marcusrbrown/systematic

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for ce:brainstorm

README.md
[![agentmods](https://agentmods.dev/badge/skills/marcusrbrown/systematic/ce-brainstorm.svg)](https://agentmods.dev/skills/marcusrbrown/systematic/ce-brainstorm)
Your own site
<a href="https://agentmods.dev/skills/marcusrbrown/systematic/ce-brainstorm"><img src="https://agentmods.dev/badge/skills/marcusrbrown/systematic/ce-brainstorm.svg" alt="Measured on agentmods" height="20"></a>
Per session 106 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,625 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00106 $0.03625
Opus 5 $0.00053 $0.01813
Sonnet 5 $0.00021 $0.00725
Haiku 4.5 $0.00011 $0.00363

Measured 3d ago against content hash c1a5d3ddb7ea, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

ce:brainstorm scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/ce-brainstorm/SKILL.md · 218 lines

How it starts

The opening of the file, as written. The whole thing — 218 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Brainstorm a Feature or Improvement

Note: The current year is 2026. Use this when dating requirements documents.

Brainstorming helps answer WHAT to build through collaborative dialogue. It precedes /ce:plan, which answers HOW to build it.

The durable output of this workflow is a requirements document. In other workflows this might be called a lightweight PRD or feature brief. In compound engineering, keep the workflow name brainstorm, but make the written artifact strong enough that planning does not need to invent product behavior, scope boundaries, or success criteria.

This skill does not implement code. It explores, clarifies, and documents decisions for later planning or execution.

IMPORTANT: All file references in generated documents must use repo-relative paths (e.g., src/models/user.rb), never absolute paths. Absolute paths break portability across machines, worktrees, and teammates.

Core Principles

  1. Assess scope first - Match the amount of ceremony to the size and ambiguity of the work.
  2. Be a thinking partner - Suggest alternatives, challenge assumptions, and explore what-ifs instead of only extracting requirements.
  3. Resolve product decisions here - User-facing behavior, scope boundaries, and success criteria belong in this workflow. Detailed implementation belongs in planning.
  4. Keep implementation out of the requirements doc by default - Do not include libraries, schemas, endpoints, file layouts, or code-level design unless the brainstorm itself is inherently about a technical or architectural change.
  5. Right-size the artifact - Simple work gets a compact requirements document or brief alignment. Larger work gets a fuller document. Do not add ceremony that does not help planning.
  6. Apply YAGNI to carrying cost, not coding effort - Prefer the simplest approach that delivers meaningful value. Avoid speculative complexity and hypothetical future-proofing, but low-cost polish or delight is worth including when its ongoing cost is small and easy to maintain.

Read the full file on GitHub · 218 lines

Files

What ships with it

7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 218 lines · 106 tokens per session scan A c1a5d3ddb7ea

Subscribe to this mod's changes

ce:brainstorm is a skill published in the GitHub repository marcusrbrown/systematic (24 stars, last pushed today), licensed MIT. It adds 106 tokens to every session and 3,625 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.