# Specifica

> Specifica is an open, Git-native spec format: a `.specifica/` folder of plain GitHub-flavored markdown (`principles.md`, plus `spec.md`, `design.md` and `tasks.md` per item) that people review and AI coding agents build from. MIT-licensed, by Cognium Labs. Tagline: the open spec format for AI-built software.

- `principles.md` holds project-wide rules; each item folder (a release such as `mvp`, a feature, a migration) holds `spec.md` (what: requirements and edge cases as checkboxes), `design.md` (how: data, flows, decisions, Mermaid diagrams) and `tasks.md` (the work, as a machine-readable checklist). All files are optional.
- No custom syntax: if GitHub renders it, it is valid.
- To build from a spec: read principles → spec → design → tasks, build in the order of tasks.md, treat each requirement and edge case as an acceptance check, tick tasks as they are done, and change the spec only with the user.

## Docs

- [Format reference](https://specifica.org/format.md): directory structure, the files, conventions, packages, rules (markdown)
- [Full text for LLMs](https://specifica.org/llms-full.txt): the format reference and FAQ in one file

## Tools

- [Specifica Playground](https://specifica-playground.pages.dev/): write a spec by chatting with an AI, level up examples, then download it or copy it for a coding agent; runs in the browser with the visitor's own model key
- [@specifica/format](https://www.npmjs.com/package/@specifica/format): parse and serialize the format (TypeScript, no dependencies)
- [@specifica/store](https://www.npmjs.com/package/@specifica/store): storage adapter interface for Specifica backends

## Optional

- [Source on GitHub](https://github.com/cogniumhq/specifica): the format specification and packages
- [Cognium Labs](https://cognium.net): the maintainer