speckit.specify

A command for turning a natural-language description of a software change into a feature specification. A feature specification records the intended behavior and requirements before coding begins.

In plain words
What is it for?
Use it when starting a new feature or updating an existing specification from a description of the desired behavior.
Why use it?
It gives an informal idea a structured written form, making the requested change easier to understand and plan.

Command for Claude Code

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/spillwavesolutions/agent-brain/speckit.specify
Clone the repo
git clone --depth 1 https://github.com/SpillwaveSolutions/agent-brain

Made for: Claude Code.

Per session 13 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,834 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 73% copy Near-identical to another mod 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 $0.00013 $0.02834
Opus 5 $0.00006 $0.01417
Sonnet 5 $0.00003 $0.00567
Haiku 4.5 $0.00001 $0.00283

Measured 2d ago against content hash 42a4389ca06d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

speckit.specify 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.

Origin

This is a copy

73% identical to specify — 195 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.claude/commands/speckit.specify.md · 261 lines

How it starts

The opening of the file, as written. The whole thing — 261 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Spec directory: All SDD artifacts live under .speckit/ (features, templates, scripts, memory).

User Input

$ARGUMENTS

You MUST consider the user input before proceeding (if not empty).

Outline

The text the user typed after /speckit.specify in the triggering message is the feature description. Assume you always have it available in this conversation even if $ARGUMENTS appears literally below. Do not ask the user to repeat it unless they provided an empty command.

Given that feature description, do this:

  1. Generate a concise short name (2-4 words) for the branch:

    • Analyze the feature description and extract the most meaningful keywords
    • Create a 2-4 word short name that captures the essence of the feature
    • Use action-noun format when possible (e.g., "add-user-auth", "fix-payment-bug")
    • Preserve technical terms and acronyms (OAuth2, API, JWT, etc.)
    • Keep it concise but descriptive enough to understand the feature at a glance
    • Examples:
      • "I want to add user authentication" → "user-auth"
      • "Implement OAuth2 integration for the API" → "oauth2-api-integration"
      • "Create a dashboard for analytics" → "analytics-dashboard"
      • "Fix payment processing timeout bug" → "fix-payment-timeout"
  2. Check for existing branches before creating new one:

    a. First, fetch all remote branches to ensure we have the latest information:

    git fetch --all --prune
    

    b. Find the highest feature number across all sources for the short-name:

    • Remote branches: git ls-remote --heads origin | grep -E 'refs/heads/[0-9]+-<short-name>$'
    • Local branches: git branch | grep -E '^[* ]*[0-9]+-<short-name>$'
    • Specs directories: Check for directories matching .speckit/features/[0-9]+-<short-name>

    c. Determine the next available number:

    • Extract all numbers from all three sources
    • Find the highest number N
    • Use N+1 for the new branch number

Read the full file on GitHub · 261 lines

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 · 261 lines · 13 tokens per session scan A 42a4389ca06d

Subscribe to this mod's changes

speckit.specify is a command published in the GitHub repository SpillwaveSolutions/agent-brain (117 stars, last pushed 3d ago), licensed MIT. It adds 13 tokens to every session and 2,834 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 73% identical to specify, differing in 195 lines, and is treated as a copy.