---
title: "Connecting to Base"
description: "Connect to Base mainnet or Sepolia using public endpoints, your own node, or a third-party provider."
source: https://basehub.org/integration-guides/connecting/
---
import CodeColumns from '../../../components/CodeColumns.astro';

Connect to Base mainnet or the Sepolia testnet using public RPC endpoints, your own node, or a third-party provider.

## Network parameters

### Base Mainnet

| Parameter | Value |
|-----------|-------|
| Network name | Base |
| Chain ID | `8453` (`0x2105`) |
| Currency | ETH |
| Block time | 2 seconds |
| Flashblock interval | 200ms |
| L1 settlement | Ethereum Mainnet |
| Explorer | [basescan.org](https://basescan.org) |

### Base Sepolia (testnet)

| Parameter | Value |
|-----------|-------|
| Network name | Base Sepolia |
| Chain ID | `84532` (`0x14a34`) |
| Currency | ETH (testnet) |
| Block time | 2 seconds |
| L1 settlement | Ethereum Sepolia |
| Explorer | [sepolia.basescan.org](https://sepolia.basescan.org) |

## Public RPC endpoints

Base provides public RPC endpoints for general use:

| Network | HTTP Endpoint | WebSocket Endpoint |
|---------|---------------|-------------------|
| Mainnet | `https://mainnet.base.org` | `wss://mainnet.base.org` |
| Sepolia | `https://sepolia.base.org` | `wss://sepolia.base.org` |

:::note
Public endpoints are rate-limited and intended for development and light usage. For production, run your own node or use a third-party provider.
:::

## Connecting with common tools

### curl

<CodeColumns>
<div>

A raw JSON-RPC `POST` request returns the latest block number as a hex string.

This is the lowest-common-denominator way to talk to Base — useful for sanity-checking that an endpoint is alive.

</div>

```bash
curl -X POST https://mainnet.base.org \
  -H "Content-Type: application/json" \
  -d '{
    "method": "eth_blockNumber",
    "params": [],
    "id": 1,
    "jsonrpc": "2.0"
  }'
```

</CodeColumns>

### cast (Foundry)

<CodeColumns>
<div>

Foundry's `cast` wraps every standard JSON-RPC method behind a clean CLI. Point it at any Base endpoint with `--rpc-url`.

</div>

```bash
cast block-number --rpc-url https://mainnet.base.org

cast balance 0xYourAddress --rpc-url https://mainnet.base.org

cast chain-id --rpc-url https://mainnet.base.org
```

</CodeColumns>

### ethers.js

<CodeColumns>
<div>

`JsonRpcProvider` is the standard ethers entry point. It works against any Base endpoint — public, your own node, or a provider.

</div>

```javascript
import { JsonRpcProvider } from "ethers";

const provider = new JsonRpcProvider("https://mainnet.base.org");

const blockNumber = await provider.getBlockNumber();
console.log("Current block:", blockNumber);

const balance = await provider.getBalance("0xYourAddress");
console.log("Balance:", balance.toString(), "wei");
```

</CodeColumns>

### viem

<CodeColumns>
<div>

viem ships chain definitions for both Base networks. `createPublicClient` selects the right RPC defaults automatically.

</div>

```typescript
import { createPublicClient, http } from "viem";
import { base, baseSepolia } from "viem/chains";

const client = createPublicClient({
  chain: base,
  transport: http(),
});

const blockNumber = await client.getBlockNumber();
console.log("Current block:", blockNumber);

const testnetClient = createPublicClient({
  chain: baseSepolia,
  transport: http(),
});
```

</CodeColumns>

### MetaMask / wallet configuration

To add Base to a wallet manually:

| Field | Mainnet | Sepolia |
|-------|---------|---------|
| Network Name | Base | Base Sepolia |
| RPC URL | `https://mainnet.base.org` | `https://sepolia.base.org` |
| Chain ID | `8453` | `84532` |
| Currency Symbol | ETH | ETH |
| Block Explorer URL | `https://basescan.org` | `https://sepolia.basescan.org` |

## Running your own node

For production, running your own Base node gives full control over rate limits, latency, and data availability.

### Quick start

The fastest path is the pre-built Docker image:

```bash
docker pull ghcr.io/base/base-reth-node:latest

docker run -d \
  --name base-node \
  -p 8545:8545 \
  -p 8546:8546 \
  -p 30303:30303 \
  -v base-data:/data \
  ghcr.io/base/base-reth-node:latest \
  --http \
  --http.addr 0.0.0.0 \
  --http.port 8545 \
  --http.api eth,net,web3,txpool \
  --ws \
  --ws.addr 0.0.0.0 \
  --ws.port 8546
```

For full instructions:

- [Building from source](/getting-started/building/) — compile the node binary.
- [Running the node](/getting-started/running/) — configuration and startup.
- [Docker](/getting-started/docker/) — containerized deployment.
- [Node deployment](/node-operations/deployment/) — production deployment guide.

### Node sync modes

| Mode | Description | Disk usage | Sync time |
|------|-------------|------------|-----------|
| Full | Executes all transactions from genesis. | High | Days |
| Snap | Downloads state snapshots, then follows chain tip. | Moderate | Hours |

## JSON-RPC interface

Base nodes expose the standard Ethereum JSON-RPC interface. The following namespaces are available:

### Standard namespaces

| Namespace | Description |
|-----------|-------------|
| `eth` | Core Ethereum methods — blocks, transactions, state queries, gas estimation. |
| `net` | Network information — peer count, version, listening status. |
| `web3` | Utility methods — client version, SHA3. |
| `txpool` | Transaction pool inspection (see [Transaction Pool](/integration-guides/txpool/)). |
| `debug` | Debug methods — trace transactions, get raw block data (enable with `--http.api debug`). |

### Base-specific namespaces

| Namespace | Description |
|-----------|-------------|
| `base` | Base-specific methods including metering (see [Metering RPC](/integration-guides/metering-rpc/)). |

### Commonly used methods

| Method | Description |
|--------|-------------|
| `eth_blockNumber` | Returns the latest block number. |
| `eth_getBlockByNumber` | Returns block data by number or tag. |
| `eth_getBlockByHash` | Returns block data by hash. |
| `eth_getTransactionByHash` | Returns a transaction by hash. |
| `eth_getTransactionReceipt` | Returns a transaction receipt. |
| `eth_getBalance` | Returns account balance. |
| `eth_getTransactionCount` | Returns account nonce. |
| `eth_call` | Executes a call without creating a transaction. |
| `eth_estimateGas` | Estimates gas for a transaction. |
| `eth_sendRawTransaction` | Submits a signed transaction. |
| `eth_getCode` | Returns contract bytecode. |
| `eth_getStorageAt` | Returns storage value at a given position. |
| `eth_getLogs` | Returns logs matching a filter. |
| `eth_chainId` | Returns the chain ID. |

### Flashblocks support

The `"pending"` block tag is supported across applicable methods when flashblocks are enabled. See [Flashblocks RPC](/integration-guides/flashblocks-rpc/) for details on querying preconfirmed state.

## Troubleshooting

### Common issues

| Issue | Cause | Solution |
|-------|-------|----------|
| `429 Too Many Requests` | Rate limit exceeded on public endpoint. | Reduce request frequency or run your own node. |
| Connection refused on port 8545 | Node HTTP RPC not enabled. | Start the node with `--http` and `--http.addr 0.0.0.0`. |
| Empty response for `eth_getLogs` | Block range too large. | Reduce the `fromBlock`/`toBlock` range (max ~2000 blocks per query). |
| Wrong chain ID | Connected to wrong network. | Verify the RPC URL matches the intended network. |
| `nonce too low` | Transaction nonce already used. | Use `"pending"` tag with `eth_getTransactionCount` for the latest nonce. |

## Further reading

- [Flashblocks RPC](/integration-guides/flashblocks-rpc/) — query preconfirmed state with the `"pending"` tag.
- [Transaction Pool](/integration-guides/txpool/) — inspect and manage the txpool.
- [Metering RPC](/integration-guides/metering-rpc/) — resource metering API.
- [Node configuration](/node-operations/configuration/) — detailed node configuration options.
- [Monitoring](/node-operations/monitoring/) — observability and metrics.