• September 25, 2026
• 5 min read

SDD — Tools¶

Overview¶

GitHub Spec Kit¶

Open-source toolkit from GitHub (v1.x since August 2026). Requires Python 3.11+ and uv.

uv tool install specify-cli
specify init my-project --integration copilot
cd my-project

Integrations exist for claude, cursor-agent, codex, gemini, copilot and many more.

/speckit-constitution Create principles focused on code quality, testing, and maintainability.
/speckit-specify Build a photo organizer with albums grouped by date and a tile preview of each album.
/speckit-plan Use Vite with vanilla JavaScript. Keep images local and store metadata in SQLite.
/speckit-tasks
/speckit-implement
/speckit-converge

Bundled extensions add separate processes for bug fixing (specify extension add bug) and idea assessment (specify extension add assess).

Tip from the docs: run each command one at a time and review the result before continuing.

AWS Kiro¶

An agentic IDE (plus CLI) with specs as a first-class feature.

• Feature specs — requirements-first or design-first; produce requirements.md, design.md, tasks.md
• Bugfix specs — bugfix.md instead of requirements
• Quick Spec — generates all three files without approval gates, for well-understood features
• Analyze Requirements — asks Kiro to find inconsistencies and gaps before design
• Correctness — extracts properties from EARS requirements and generates property-based tests, keeping a traceable link between requirements and tests
• Sync Files — updates tasks.md after requirements or design change

Steering — always-on guidance in .kiro/steering/ (workspace) or ~/.kiro/steering/ (global). Default files: product.md, tech.md, structure.md. Inclusion modes: always, file match, manual (#steering-file-name), auto. AGENTS.md is recognised too.

Hooks — run shell commands or agent prompts on events: prompt submit, agent stop, pre/post tool use, file create / save / delete. Example use: run tests when a file is saved, update docs when an API changes.

OpenSpec¶

Lightweight, "built for brownfield". Requires Node.js 20.19+.

npm install -g @fission-ai/openspec@latest
cd your-project
openspec init

Command spelling varies by tool (e.g. /opsx-propose in Cursor and Copilot, $openspec-propose in Codex). Thoughtworks Radar (April 2026) lists OpenSpec in Assess and highlights its spec deltas.

Tessl¶

• Spec Registry — thousands of specs for open-source libraries, so agents use real APIs instead of hallucinating them
• Tessl Framework — specs live in the codebase as long-term memory; each capability links to its tests; generated code can be marked "DO NOT EDIT" (spec-as-source)
• Workflow tile: tessl install tessl-labs/spec-driven-development

BMAD Method¶

"Agile AI-Driven Development": a set of specialised agent roles (product, architecture, UX, developer, test architect) and workflows. The process "sizes itself to the work: small changes go straight to build."

npx skills add bmad-code-org/BMAD-METHOD

In Claude Code: /plugin marketplace add bmad-code-org/bmad-plugins.

Plain Markdown With Any Agent¶

Review prompt from Claude Code's docs, useful as a verification step:

Review the rate limiter diff against PLAN.md. Check that every requirement is implemented,
the listed edge cases have tests, and nothing outside the task's scope changed.

How to Choose¶

• Small change, one sentence → no spec, just do it
• Feature in a new project, team wants a full process → Spec Kit
• Change in a large existing codebase → OpenSpec (delta specs) or plain SPEC.md
• IDE with specs, steering and hooks built in → Kiro
• Specs as permanent source of truth, library specs → Tessl
• Big project with many roles → BMAD
• Don't want another tool → plan mode + SPEC.md + AGENTS.md
• Shared domain knowledge the agent keeps re-learning → an OKF bundle next to the specs

See also¶

• Spec-Driven Development
• SDD — Concepts & Workflow
• SDD — Writing Good Specs
• SDD — Open Knowledge Format (OKF)
• AI Skills for Coding Agents