spec

A set of rules for Spec Driven Development, an approach that uses a written specification to guide software work.

In plain words
What is it for?
It is for projects that follow Spec Driven Development.
Why use it?
It provides structure for working from a defined specification, although the input does not describe the specific rules.

Cursor rule for Cursor

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 rules/amaynez/kiro-style-sdd/spec
Clone the repo
git clone --depth 1 https://github.com/amaynez/kiro-style-sdd

Made for: Cursor.

Per session 38 This file is loaded in full into every session.
When invoked 38 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00038 $0.00038
Opus 5 $0.00019 $0.00019
Sonnet 5 $0.00008 $0.00008
Haiku 4.5 $0.00004 $0.00004

Measured 2d ago against content hash 8dad0850c0f1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

spec 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.

.cursor/rules/spec.mdc · 7 lines

The source is not reproduced here

Licensed GPL-3.0

The repository is licensed GPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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 · 7 lines · 38 tokens per session scan A 8dad0850c0f1

Subscribe to this mod's changes

spec is a cursor rule published in the GitHub repository amaynez/kiro-style-sdd (78 stars, last pushed 3mo ago), licensed GPL-3.0. It adds 38 tokens to every session, about $0.0002 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.