Spec Registry

Help agents understand your dependencies

Install version-accurate specs that give agents guidance on every library in your project.

npx @tessl/cli registry sync

Featured Specs

spec:npm-tanstack--react-router

spec:pypi-langgraph-sdk

pypi17 days ago

spec:pypi-streamlit

pypi21 days ago

spec:pypi-pydantic-ai

pypi21 days ago

spec:pypi-openai

pypi21 days ago

spec:pypi-fastmcp

pypi21 days ago

spec:pypi-fastapi

pypi21 days ago

spec:pypi-anthropic

pypi21 days ago

spec:npm-tanstack--react-start

spec:npm-react-aria

spec:npm-express

spec:npm-anthropic-ai--sdk

spec:npm-svelte

spec:npm-lodash

spec:maven-apache-spark

maven21 days ago

10,000+ specs for popular open-source packages

There's more...

Keep your agents on the rails with Tessl Framework

The Tessl Framework enables agents to define specifications before coding and maintain detailed, up-to-date plans throughout development, ensuring they stay on track.

Get early access