spec-kit AGENTS.md

A set of project instructions for GitHub Spec Kit, a toolkit that guides teams to write software specifications before implementation. It also explains Specify, the command-line tool that sets up Spec Kit projects and AI-agent integrations.

In plain words
What is it for?
Use it when working on Spec Kit's agent instructions, integrations, configuration, or documentation.
Why use it?
It gives contributors the repository context and the prescribed steps for adding support for another AI coding assistant.

Instructions file for CodexOpenCode

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 instructions/github/spec-kit/agents-md
Clone the repo
git clone --depth 1 https://github.com/github/spec-kit

Made for: Codex, OpenCode.

Per session 7,040 This file is loaded in full into every session.
When invoked 7,040 The same file — it is already loaded in full.
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 $0.07040 $0.07040
Opus 5 $0.03520 $0.03520
Sonnet 5 $0.01408 $0.01408
Haiku 4.5 $0.00704 $0.00704

Measured yesterday against content hash 09e95ebd0a86, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

spec-kit AGENTS.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 yesterday.

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.

AGENTS.md · 600 lines

How it starts

The opening of the file, as written. The whole thing — 600 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md

About Spec Kit and Specify

GitHub Spec Kit is a comprehensive toolkit for implementing Spec-Driven Development (SDD) - a methodology that emphasizes creating clear specifications before implementation. The toolkit includes templates, scripts, and workflows that guide development teams through a structured approach to building software.

Specify CLI is the command-line interface that bootstraps projects with the Spec Kit framework. It sets up the necessary directory structures, templates, and AI agent integrations to support the Spec-Driven Development workflow.

The toolkit supports multiple AI coding assistants, allowing teams to use their preferred tools while maintaining consistent project structure and development practices.


Quickstart — Add a New Integration in 5 Steps

If you are new to the codebase and want to add support for a new AI agent, here is the shortest path from zero to a working integration:

  1. Choose a base class — most agents only need MarkdownIntegration. See Choose a base class.
  2. Create a subpackage — add src/specify_cli/integrations/<package_dir>/__init__.py with the required key, config, and registrar_config fields.
  3. Register it — add one import and one _register() call in src/specify_cli/integrations/__init__.py (both alphabetical).
  4. Write a test file — create tests/integrations/test_integration_<key>.py (hyphens in the key become underscores in the filename).
  5. Run and verify — use specify init --integration <key> to exercise the full install/uninstall cycle.

Each step is expanded under Adding a New Integration. Note that agent context files (CLAUDE.md, AGENTS.md, …) are not handled by the integration — that is owned by the opt-in agent-context extension; see Context file behavior.


Integration Architecture

Each AI agent is a self-contained integration subpackage under src/specify_cli/integrations/<key>/. The subpackage exposes a single class that declares all metadata and inherits setup/teardown logic from a base class. Built-in integrations are then instantiated and added to the global INTEGRATION_REGISTRY by src/specify_cli/integrations/__init__.py via _register_builtins().

Read the full file on GitHub · 600 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. yesterday First seen · 600 lines · 7,040 tokens per session scan A 09e95ebd0a86

Subscribe to this mod's changes

spec-kit AGENTS.md is an instructions file published in the GitHub repository github/spec-kit (132,298 stars, last pushed 3d ago), licensed MIT. It adds 7,040 tokens to every session, about $0.0352 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.