Borrowing it
Nothing to install: this file belongs to alfredoperez/sdd. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/alfredoperez/sdd/main/CLAUDE.mdgit clone --depth 1 https://github.com/alfredoperez/sddWrote 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.
[](https://agentmods.dev/instructions/alfredoperez/sdd/claude-md)<a href="https://agentmods.dev/instructions/alfredoperez/sdd/claude-md"><img src="https://agentmods.dev/badge/instructions/alfredoperez/sdd/claude-md.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.02023 | $0.02023 |
| Opus 5 | $0.01012 | $0.01012 |
| Sonnet 5 | $0.00405 | $0.00405 |
| Haiku 4.5 | $0.00202 | $0.00202 |
Grade A, and why
sdd CLAUDE.md 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 7d 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.
How it starts
The opening of the file, as written. The whole thing — 110 lines — stays where its author put it; the contents beside it link to each section on GitHub.
SDD — Spec-Driven Development
Overview
SDD is a structured workflow for AI-assisted development. Every feature goes through: specify → plan → tasks → implement. Small changes auto-detect and fast-track through the pipeline.
Core Concepts
Slug Rules
- 2–4 words, action-noun format, lowercase, hyphens
- Examples:
clickable-file-refs,fix-payment-timeout - Preserve technical terms (OAuth2, JWT, API)
Spec Directory
- All specs live in
specs/{NNN}-{slug}/ - NNN is zero-padded to 3 digits (001, 002, ...)
- Each spec directory contains:
spec.md,plan.md,tasks.md,.spec-context.json
.spec-context.json Format
The runtime state file is specs/{NNN}-{slug}/.spec-context.json. Every spec has one. SDD skills and (optionally) the SpecKit Companion VS Code extension both read and write it; both authors must follow read-then-merge and append-only transitions[]. /sdd:implement updates it via a per-spec event journal (a write-ahead log drained into the file at batched boundaries) rather than writing on every task.
Canonical reference: docs/STATE.md — narrative + field tables.
Machine-readable schema: lib/schemas/spec-context.schema.json (JSON Schema draft 2020-12).
When changing the schema (adding/renaming/removing a field, changing an enum, deprecating something), update both files in the same PR. See the Docs Sync Rule below.
Commit Conventions
- No AI attribution lines (no Co-Authored-By, no "Generated with...")
Complexity Detection
| Signal | Mode |
|---|---|
| Touches ≤3 existing files, change is <10 lines | minimal |
| Pure style or config tweak | minimal |
| Touches 4+ files, or adds a new component/service | normal |
| Introduces new public behavior or API | normal |
If unclear, default to normal.
Fast Path (Minimal Mode)
When /sdd:specify detects a minimal change, it auto-generates plan.md + tasks.md in one shot. Jump straight to /sdd:implement.
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.
- 7d ago First seen · 110 lines · 2,023 tokens per session scan A 0c6f41292248
sdd CLAUDE.md is an instructions file published in the GitHub repository alfredoperez/sdd (2 stars, last pushed 15d ago), licensed MIT. It adds 2,023 tokens to every session, about $0.0101 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.
Other instructions, from other repositories
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
spec-kit AGENTS.md
AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.