What is AmbyKit AGENTS.md?

Project instructions for AmbyKit, a Node and TypeScript command-line tool that uses Spec-Driven Development: defining requirements and plans before writing code.

Use them when changing AmbyKit's project structure, templates, prompts, emitters, builds, or tests, including support for tools such as Claude Code, Cursor, and GitHub Copilot.

They give coding assistants consistent rules for working on AmbyKit itself and keep different assistants' command files generated from one shared source.

How ambystechcom/AmbyKit configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to ambystechcom/AmbyKit. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/ambystechcom/AmbyKit/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/ambystechcom/AmbyKit

Made for: Codex, OpenCode.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/ambystechcom/ambykit/agents-md/github.svg)](https://agentmods.dev/instructions/ambystechcom/ambykit/agents-md)

Your own site

<a href="https://agentmods.dev/instructions/ambystechcom/ambykit/agents-md"><img src="https://agentmods.dev/badge/instructions/ambystechcom/ambykit/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

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Per session 1,235 This file is loaded in full into every session.

When invoked 1,235 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.01235	$0.01235
Opus 5.5	$0.00494	$0.00494
Sonnet 5.5	$0.00247	$0.00247
Haiku 4.5	$0.00123	$0.00123

Measured 2d ago against content hash 1623f53e2656, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

AmbyKit 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 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.

AGENTS.md · 81 lines

How it starts

The opening of the file, as written. The whole thing — 81 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md — AmbyKit

Guidance for AI coding assistants working on the AmbyKit codebase itself. (For using AmbyKit in your own project, see README.md and docs/.)

What AmbyKit is

AmbyKit is a Spec-Driven Development (SDD) framework distributed as a Node/TypeScript CLI (@ambystech/ambykit, bin ambykit). It helps AI coding assistants build better software by producing structured artifacts — a project constitution, user stories, testable requirements, UI design, an implementation plan, and an ordered task list — before code is written.

The core design is author-once, emit-per-tool: one neutral source of truth (templates + phase prompts) is translated by per-tool emitters into each assistant's native command/rules format (Claude Code, OpenCode, GitHub Copilot + CLI, Cursor + CLI, Antigravity IDE + CLI).

Golden rules

Author once, emit per tool. Never hand-maintain per-tool command files as source. The neutral source lives in src/templates/ and src/prompts/; emitters in src/emitters/ generate tool files (e.g. .claude/commands/amby.*.md, .github/prompts/). If you find yourself editing those by hand, stop — edit the neutral source and re-run ambykit sync instead.
BaseEmitter / BaseCommand hold shared logic. New tool support = a thin subclass of BaseEmitter that sets its commandSurface/paths and overrides only what differs. New CLI verb = a subclass of BaseCommand implementing execute(). Don't duplicate orchestration.
Token frugality is a feature. Phase prompts and templates must minimize tokens the assistant reads/writes: progressive disclosure (load only the artifact a phase needs via @path), reference by stable ID instead of restating, and patch-in-place rather than regenerate. See docs/architecture.md → Token efficiency.
We dogfood AmbyKit on AmbyKit. Features are specced under specs/ using the AmbyKit workflow. The repo's own .claude/ etc. are generated by ambykit sync and must stay in sync (CI checks).

Read the full file on GitHub · 81 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.

2d ago Changed · +18 tokens per session 1623f53e2656
11d ago Changed · +1 tokens per session 6d3ad1150ee4
2mo ago First seen · 81 lines · 1,216 tokens per session scan A cc03022e9cc7

Subscribe to this mod's changes

AmbyKit AGENTS.md is an instructions file published in the GitHub repository ambystechcom/AmbyKit (2 stars, last pushed 2d ago), licensed MIT. It adds 1,235 tokens to every session, about $0.0049 per session on Opus 5.5. 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.

Planning agent-skills agentic-coding agentic-workflow ai-coding ai-tools spec

AmbyKit AGENTS.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
AmbyKit AGENTS.mdambystechcom/AmbyKit	Instructions file	2	2d ago	MIT	A	1,235	Codex, OpenCode
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	today	MIT	A	7,461	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	5,516	GitHub Copilot
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	today	MIT	A	4,680	Codex, OpenCode
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	275k	3d ago	MIT	A	4,313	Codex, OpenCode

AmbyKit: Instructions file for Codex