brightiron / ponder

A backend framework for crypto apps

Ponder

Ponder is an open-source framework for blockchain application backends.

Documentation

Visit ponder.sh for documentation, guides, and the API reference.

Support

Join Ponder's telegram chat for support, feedback, and general chatter.

Features

✅  Local development server with hot reloading
✅  create-ponder CLI tool to get started from an Etherscan link or Graph Protocol subgraph
✅  End-to-end type safety using viem and ABIType
✅  Autogenerated GraphQL API
✅  Easy to deploy anywhere using Node.js/Docker
✅  Supports all Ethereum-based blockchains, including test nodes like Anvil
✅  Index events from multiple chains in the same app
✅  Reconciles chain reorganization
✅  Factory contracts
🏗️  Process transactions calls (in addition to logs)
🏗️  Run effects (e.g. send an API request) in indexing code

Quickstart

1. Run create-ponder

You will be asked for a project name, and if you are using a template (recommended). Then, the CLI will create a project directory, install dependencies, and initialize a git repository.

npm init ponder@latest
# or
pnpm create ponder
# or
yarn create ponder

2. Start the development server

Just like Next.js and Vite, Ponder has a development server that automatically reloads when you save changes in any project file. It also prints console.log statements and errors encountered while running your code. First, cd into your project directory, then start the server.

npm run dev
# or
pnpm dev
# or
yarn dev

3. Add contracts & networks

Ponder fetches event logs for the contracts added to ponder.config.ts, and passes those events to the indexing functions you write.

// ponder.config.ts
import { http } from "viem";

import { BaseRegistrarAbi } from "./abis/BaseRegistrar";

export const config = {
  networks: [
    {
      name: "mainnet",
      chainId: 1,
      transport: http("https://eth-mainnet.g.alchemy.com/v2/..."),
    },
  ],
  contracts: [
    {
      name: "BaseRegistrar",
      network: "mainnet",
      abi: BaseRegistrarAbi,
      address: "0x57f1887a8BF19b14fC0dF6Fd9B2acc9Af147eA85",
      startBlock: 9380410,
    },
  ],
};

4. Define your schema

The ponder.schema.ts file contains the database schema, and defines the shape data that the GraphQL API serves.

// ponder.schema.ts

import { createSchema } from "@ponder/core";

export default createSchema((p) => ({
  EnsName: p.createTable({
    id: p.string(),
    name: p.string(),
    owner: p.string(),
    registeredAt: p.int(),
  }),
}));

5. Write indexing functions

Files in the src/ directory contain indexing functions, which are TypeScript functions that process a contract event. The purpose of these functions is to insert data into the entity store.

// src/BaseRegistrar.ts

import { ponder } from "@/generated";

ponder.on("BaseRegistrar:NameRegistered", async ({ event, context }) => {
  const { EnsName } = context.entities;
  const { name, owner } = event.params;

  await EnsName.create({
    id: `${name}-${owner}`,
    data: {
      name: name,
      owner: owner,
      registeredAt: event.block.timestamp,
    },
  });
});

See the create & update records docs for a detailed guide on writing indexing functions.

6. Query the GraphQL API

Ponder automatically generates a frontend-ready GraphQL API based on your project's schema.graphql. The API serves the data that you inserted in your indexing functions.

{
  ensNames(first: 2) {
    name
    owner
    registeredAt
  }
}

{
  "ensNames": [
    {
      "name": "vitalik.eth",
      "owner": "0x0904Dac3347eA47d208F3Fd67402D039a3b99859",
      "registeredAt": 1580345271
    },
    {
      "name": "joe.eth",
      "owner": "0x6109DD117AA5486605FC85e040ab00163a75c662",
      "registeredAt": 1580754710
    }
  ]
}

That's it! Visit ponder.sh for documentation, guides for deploying to production, and the API reference.

Contributing

If you're interested in contributing to Ponder, please read the contribution guide.

Packages

• @ponder/core
• create-ponder
• eslint-config-ponder

About

Ponder is MIT-licensed open-source software.