design

A command for turning an approved feature specification into a technical design. It covers affected code, interface changes, failure handling, and rollback.

In plain words
What is it for?
Use it after a Brownspec feature has passed its specification checks, or to design the most recently modified feature when no feature name is supplied.
Why use it?
It gives implementation work a written technical approach and checks what else may be affected before coding begins. It also records whether the dependency review used a code graph or text search.

Command

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 commands/yknnv/brownspec/design
Clone the repo
git clone --depth 1 https://github.com/yknnv/brownspec
Per session 19 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 93 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 $0.00019 $0.00093
Opus 5 $0.00010 $0.00046
Sonnet 5 $0.00004 $0.00019
Haiku 4.5 $0.00002 $0.00009

Measured 2d ago against content hash da56de0c34d0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

design 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 2d 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.

commands/design.md · 12 lines

What it actually says

Use the design skill from the Brownspec plugin.

Feature: $ARGUMENTS — if empty, use the most recently modified directory under .brownspec/features/, and say which one you picked.

Establish the blast radius first, and state its provenance — graph or text-search.

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. 2d ago First seen · 12 lines · 19 tokens per session scan A da56de0c34d0

Subscribe to this mod's changes

design is a command published in the GitHub repository yknnv/brownspec (2 stars, last pushed 4d ago), licensed MIT. It adds 19 tokens to every session and 93 once invoked, about $0.0001 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 2026-08-31.