npm package: @ponder/core
Description: An open-source framework for crypto application backends
Latest version: 0.7.17

# Ponder

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

## Documentation

Visit [ponder.sh](https://ponder.sh) for documentation, guides, and the API reference.

## Support

Join [Ponder's telegram chat](https://t.me/ponder_sh) for support, feedback, and general chatter.

## Features

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

## Quickstart

### 1. Run `create-ponder`

You will be asked for a project name, and if you are using a [template](https://ponder.sh/docs/api-reference/create-ponder#templates) (recommended). Then, the CLI will create a project directory, install dependencies, and initialize a git repository.

```bash
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.

```bash
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.

```ts
// ponder.config.ts

import { createConfig } from "@ponder/core";
import { http } from "viem";
 
import { BaseRegistrarAbi } from "./abis/BaseRegistrar";
 
export default createConfig({
  networks: {
    mainnet: { 
      chainId: 1,
      transport: http("https://eth-mainnet.g.alchemy.com/v2/...")
    },
  },
  contracts: {
    BaseRegistrar: {
      abi: BaseRegistrarAbi,
      network: "mainnet",
      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.

```ts
// ponder.schema.ts

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

export const ensName = onchainTable("ens_name", (t) => ({
  name: p.text().primaryKey(),
  owner: p.text().notNull(),
  registeredAt: p.integer().notNull(),
}));
```

### 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.

```ts
// src/BaseRegistrar.ts

import { ponder } from "@/generated";
import * as schema from "../ponder.schema";

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

  await context.db.insert(schema.ensName).values({
    name: name,
    owner: owner,
    registeredAt: event.block.timestamp,
  });
});
```

See the [create & update records](https://ponder.sh/docs/indexing/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 `ponder.schema.ts` file. The API serves data that you inserted in your indexing functions.

```ts
{
  ensNames(limit: 2) {
    items {
      name
      owner
      registeredAt
    }
  }
}
```

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

That's it! Visit [ponder.sh](https://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](/.github/CONTRIBUTING.md).

## Packages

- `@ponder/core`
- `@ponder/utils`
- `create-ponder`
- `eslint-config-ponder`

## About

Ponder is MIT-licensed open-source software.

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