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Installing Lexicons

Using Lexicons in your dev environment

Using lex

Lexicon schemas enable code generation with types and validation. Our SDKs each install a lex tool that lets you generate a type-safe client that knows which parameters each AT endpoint expects.

TypeScript

First, install the @atproto/lex package:

npm install -g @atproto/lex

This provides the lex command, which you can use to install Lexicons into a local project:

lex install app.bsky.feed.post app.bsky.feed.like

This creates:

  • lexicons.json - manifest tracking installed Lexicons and their versions (CIDs)
  • lexicons/ - directory containing the Lexicon JSON files

Finally, generate TypeScript schemas from the installed Lexicons:

lex build

This generates TypeScript files in ./src/lexicons. Now, you'll have these functions available to use in your code:

import { Client } from '@atproto/lex'
import * as app from './lexicons/app.js'

// Create an unauthenticated client instance
const client = new Client('https://public.api.bsky.app')

// Start making requests using generated schemas
const response = await client.call(app.bsky.actor.getProfile, {
  actor: 'pfrazee.com',
})

For more guidance on working with lex, refer to the readme.

Further Reading and Resources