SDK Reference

Overview

SDK reference for Scrawn functions, pricing DSL, and production patterns

Everything you need to integrate Scrawn into your application.

Configuration

scrawn() is the factory that creates your billing instance:

// scrawn/biller.ts
import { scrawn } from "@scrawn/core";
import { TAGS, EXPRESSIONS } from "./pricerefs";

export const biller = scrawn({
  apiKey: process.env.SCRAWN_KEY,
  baseURL: process.env.SCRAWN_BASE_URL,
  httpUrl: process.env.SCRAWN_HTTP_URL,
  tags: TAGS,
  expressions: EXPRESSIONS,
});

The factory accepts a single config object:

Prop

Type

Functions

The core methods you call in your code to track usage, bill AI tokens, and collect payments.

Usage Tracking

Track billable events manually or automatically with middleware.

AI Token Billing

Meter AI token usage per-call with streaming, the AI SDK wrapper, or manual tracking.

Collect Payments

Generate a checkout link when a user's balance crosses your threshold.

Webhook Verification

Verify incoming webhooks - fetches the public key, verifies the signature, returns the typed event.

Reference & Guides

Pricing expressions, production patterns, and framework integration.

Pricing DSL

Type-safe expressions for pricing logic - mul, add, tag, inputTokens, and more.

Framework Recipes

Quick integration patterns for Express, Next.js, Fastify, NestJS, tRPC, Hono, and Nuxt.

Dashboard Setup

Set up the Scrawn Dashboard to manage API keys and monitor usage

Usage Tracking

Track billable events with basicUsageEventConsumer and middlewareEventConsumer

On this page

Reference & Guides