quicknode

What this skill does

# Quicknode: Blockchain Data Access for Agents

Quicknode provides high-performance RPC endpoints across 77+ blockchain networks including all chains Bankr supports: Base, Ethereum, Polygon, Solana, and Unichain.

Two ways to access:

- **API key**: Create a Quicknode account, get an endpoint URL with auth baked in. Full access to all products and settings.
- **x402 (no account needed)**: Any wallet with USDC can authenticate and pay per request. Install `@quicknode/x402` and start querying immediately.

## x402 Access (Recommended for Agents)

x402 is ideal for autonomous agents. No signup, no API keys. Pay with USDC on Base, Polygon, or Solana.

```typescript
import { createQuicknodeX402Client } from "@quicknode/x402";

const client = await createQuicknodeX402Client({
  baseUrl: 'https://x402.quicknode.com',
  network: "eip155:84532",   // pay on Base Sepolia (testnet)
  evmPrivateKey: process.env.PRIVATE_KEY,
  preAuth: true,             // pre-authenticates via SIWX for faster payment flow
});

// Pay on Base, query any chain
const res = await client.fetch("https://x402.quicknode.com/ethereum-mainnet", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ jsonrpc: "2.0", method: "eth_blockNumber", params: [], id: 1 }),
});
```

Install: `npm install @quicknode/x402`

Credit pricing:
- Testnet: 100 credits for $0.01 USDC
- Mainnet: 1,000,000 credits for $10 USDC
- 1 credit per successful JSON-RPC response

Full x402 docs: https://x402.quicknode.com/llms.txt

## API Key Access

Quicknode endpoints include authentication in the URL:

```
https://{ENDPOINT_NAME}.{NETWORK}.quiknode.pro/{API_KEY}/
```

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

const client = createPublicClient({
  chain: base,
  transport: http(process.env.QUICKNODE_RPC_URL),
});

const block = await client.getBlockNumber();
```

## Common Agent Operations

### Check Native Balance (EVM)

```typescript
const balance = await client.getBalance({ address: "0x..." });
```

Or raw RPC:
```json
{ "jsonrpc": "2.0", "method": "eth_getBalance", "params": ["0x...", "latest"], "id": 1 }
```

### Check ERC-20 Token Balance (EVM)

Use `eth_call` with the ERC-20 `balanceOf(address)` selector (`0x70a08231`):

```json
{
  "jsonrpc": "2.0",
  "method": "eth_call",
  "params": [{
    "to": "0xTOKEN_CONTRACT",
    "data": "0x70a08231000000000000000000000000WALLET_ADDRESS_NO_0x"
  }, "latest"],
  "id": 1
}
```

### Get Gas Estimate (EVM)

```json
{ "jsonrpc": "2.0", "method": "eth_gasPrice", "params": [], "id": 1 }
```

### Check Transaction Status (EVM)

```json
{ "jsonrpc": "2.0", "method": "eth_getTransactionReceipt", "params": ["0xTX_HASH"], "id": 1 }
```

### Solana Balance

```json
{ "jsonrpc": "2.0", "method": "getBalance", "params": ["WALLET_PUBKEY"], "id": 1 }
```

### Solana Token Accounts

```json
{
  "jsonrpc": "2.0",
  "method": "getTokenAccountsByOwner",
  "params": [
    "WALLET_PUBKEY",
    { "programId": "TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA" },
    { "encoding": "jsonParsed" }
  ],
  "id": 1
}
```

## Quicknode Marketplace Add-ons

Quicknode endpoints can be enhanced with Marketplace add-ons. Relevant ones for trading agents:

- **Token API**: `qn_getWalletTokenBalance` returns all ERC-20 balances for a wallet in one call. No need to query each token contract individually.
- **NFT API**: `qn_fetchNFTs` returns NFTs owned by an address with metadata.
- **Solana Priority Fee API**: `qn_estimatePriorityFees` returns recommended priority fees based on recent network activity. Useful for ensuring transactions land quickly.
- **Solana DAS API**: Query compressed NFTs, fungible tokens, and digital assets via methods like `getAssetsByOwner` and `searchAssets`.
- **Metis - Solana Trading API**: Jupiter-powered token swaps on Solana. Get quotes and execute swaps via `quoteGet` and `swapPost` endpoints. Docs: https://www.quicknode.com/docs/solana/metis-overview

See all add-ons: https://marketplace.quicknode.com/

These add-ons are available on API key endpoints. Enable them in the Quicknode dashboard.

## Supported Networks

All Bankr-supported chains are available on Quicknode:

| Chain | x402 Network Slug | API Key Docs |
|-------|-------------------|--------------|
| Base | `base-mainnet` | https://www.quicknode.com/docs/base |
| Ethereum | `ethereum-mainnet` | https://www.quicknode.com/docs/ethereum |
| Polygon | `polygon-mainnet` | https://www.quicknode.com/docs/polygon |
| Solana | `solana-mainnet` | https://www.quicknode.com/docs/solana |
| Unichain | `unichain-mainnet` | https://www.quicknode.com/docs/unichain |

x402 base URL: `https://x402.quicknode.com/{network-slug}`

See full list of supported chains: https://www.quicknode.com/chains

## Error Handling

- **429 Too Many Requests**: Back off and retry. Use exponential backoff.
- **402 Payment Required** (x402): Credits depleted. `@quicknode/x402` handles this automatically by triggering a new USDC payment.
- **JSON-RPC errors** (e.g., `-32000`): Method-specific errors. Check params and retry.

## Resources

- AI & Agents docs: https://www.quicknode.com/docs/build-with-ai
- Full RPC documentation (all chains): https://www.quicknode.com/docs/llms.txt
- x402 technical details: https://x402.quicknode.com/llms.txt
- Code examples (x402): https://github.com/quiknode-labs/qn-x402-examples
- Marketplace add-ons: https://marketplace.quicknode.com
- Full Quicknode skill with extended references: https://github.com/quiknode-labs/blockchain-skills/tree/main/skills/quicknode-skill