# Fission-AI/OpenSpec

Spec-driven development (SDD) for AI coding assistants.

Repository: https://github.com/Fission-AI/OpenSpec
Canonical: https://ross.abutalabs.com/products/openspec
Homepage: https://openspec.dev/
Language: TypeScript
License: MIT
License Family: permissive
Topics: spec, ai, context-engineering, engineering, planning, prd, sdlc, spec-driven-development, specification, sdd
Last push: 2026-08-26T23:24:19+00:00

## Health v2 (maintenance only)
Score: 85/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 99, longevity 28
- inputs: {"age_days": 393, "days_push": 7, "days_rel": 7, "gap_med": 3.5, "n_releases_24m": 45}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 66353, forks 4568 (observed 2026-08-28T04:12:20.719167+00:00)

## What it is
OpenSpec is a lightweight spec-driven development (SDD) framework that lets AI coding assistants like Claude Code, Cursor, and Copilot work from versioned specification files stored in the repository. It provides slash-command workflows (/opsx:explore, propose, apply, archive) that generate proposals, spec deltas, design docs, and task checklists before code is written.

## Use cases
- manage specs for ai coding assistants
- generate spec deltas before implementing changes
- keep ai agent context persistent across chat sessions
- plan features with proposals and task checklists
- review intent and requirements instead of just code diffs
- onboard developers with a browsable spec library
- add spec-driven development to an existing brownfield codebase

## When to choose
- you use AI coding assistants and want structured, reviewable change planning
- you want requirements and scenarios versioned in git alongside code
- you work on an existing codebase and need iterative, lightweight spec workflows
- you want tool-agnostic specs with no API keys or MCP servers required

## When to avoid
- you prefer heavyweight waterfall or formal requirements-management tools
- your team writes code without AI assistance and has no spec discipline needs
- you need strict compliance-grade requirements traceability

## Facets
- artifact type: cli-tool
- maturity: active
- function: developer-tools, workflow-automation, documentation, prompt-engineering, cli
- domain: developer-tools, documentation, large-language-models
- platform: cli, cross-platform
- tags: spec-driven-development, ai-coding-assistants, sdd, context-engineering, slash-commands, brownfield, automation, ai-agents, nodejs

## Member repositories
- Fission-AI/OpenSpec (main) score 85

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:12:20.719167+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T16:16:57.722362+00:00, confidence not recorded.
  - readme: https://github.com/Fission-AI/OpenSpec (fetched 2026-08-28T04:12:20.719167+00:00, sha 8364d79c8424)
  - homepage: https://openspec.dev/ (fetched 2026-08-28T17:53:17.200900+00:00, sha 26df9e82225e)
- Data as of 2026-08-30T08:39:29.467469+00:00.