> ## Documentation Index
> Fetch the complete documentation index at: https://docs.polynode.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# Polygon RPC

> Authenticated Polygon RPC with priority transaction routing

## Endpoint

```
https://rpc.polynode.dev
```

Standard Ethereum JSON-RPC over HTTPS. Drop-in replacement for any Polygon RPC — just change the URL and add your API key.

## Authentication

Every request requires a valid polynode API key. Pass it as a header:

```
x-api-key: YOUR_API_KEY
```

Or as a Bearer token:

```
Authorization: Bearer YOUR_API_KEY
```

Requests without a valid key receive a `-32000` error.

## Rate Limit

All keys are rate-limited to **2 requests per second** per IP. Exceeding this returns a `-32005` error. Batch requests count as a single request.

## Supported Methods

| Method                      | Source               | Description                               |
| --------------------------- | -------------------- | ----------------------------------------- |
| `eth_sendRawTransaction`    | **Priority routing** | P2P delivery to block-producing validator |
| `eth_chainId`               | Local                | Returns `0x89` (137)                      |
| `eth_blockNumber`           | Local                | Latest block from P2P network             |
| `eth_gasPrice`              | Local                | Calibrated for optimal block positioning  |
| `net_version`               | Local                | Returns `137`                             |
| `net_peerCount`             | Local                | Connected P2P peer count                  |
| `web3_clientVersion`        | Local                | Returns `PolyNode/1.0.0`                  |
| `eth_call`                  | P2P node             | Contract read calls                       |
| `eth_getBalance`            | P2P node             | Account balance queries                   |
| `eth_getTransactionCount`   | P2P node             | Nonce queries                             |
| `eth_estimateGas`           | P2P node             | Gas estimation                            |
| `eth_getBlockByNumber`      | P2P node             | Block data                                |
| `eth_getTransactionReceipt` | P2P node             | Transaction receipts                      |
| `eth_getLogs`               | P2P node             | Log queries (requires address filter)     |

<Warning>
  **Current-state only.** `eth_getBalance`, `eth_getStorageAt`, and `eth_call` only support the `latest` block tag. Historical state at old block numbers is not available. Block and transaction data works for all blocks.
</Warning>

## Common Queries

### Check a wallet's MATIC balance

```bash theme={null}
curl -X POST https://rpc.polynode.dev \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getBalance",
    "params": ["0xYOUR_WALLET_ADDRESS", "latest"],
    "id": 1
  }'
```

The result is the balance in wei (hex). Divide by 10^18 for MATIC.

### Check a wallet's USDC balance

Use `eth_call` with the ERC-20 `balanceOf(address)` function:

```bash theme={null}
curl -X POST https://rpc.polynode.dev \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_call",
    "params": [{
      "to": "0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359",
      "data": "0x70a08231000000000000000000000000YOUR_WALLET_ADDRESS_WITHOUT_0x"
    }, "latest"],
    "id": 1
  }'
```

Replace `YOUR_WALLET_ADDRESS_WITHOUT_0x` with the 40-character address (no `0x` prefix), zero-padded to 64 characters. The result is the balance in the token's smallest unit (hex). USDC has 6 decimals.

**Common Polygon token contracts:**

| Token            | Address                                      |
| ---------------- | -------------------------------------------- |
| USDC             | `0x3c499c542cEF5E3811e1192ce70d8cC03d5c3359` |
| USDC.e (bridged) | `0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174` |
| USDT             | `0xc2132D05D31c914a87C6611C10748AEb04B58e8F` |
| WMATIC           | `0x0d500B1d8E8eF31E21C99d1Db9A6444d3ADf1270` |
| WETH             | `0x7ceB23fD6bC0adD59E62ac25578270cFf1b9f619` |

### Read any contract function

The `data` field for `eth_call` is the function selector (first 4 bytes of the keccak256 hash) followed by ABI-encoded arguments.

Common selectors:

| Function                     | Selector     | Arguments                             |
| ---------------------------- | ------------ | ------------------------------------- |
| `balanceOf(address)`         | `0x70a08231` | address (32 bytes, left-padded)       |
| `totalSupply()`              | `0x18160ddd` | none                                  |
| `decimals()`                 | `0x313ce567` | none                                  |
| `symbol()`                   | `0x95d89b41` | none                                  |
| `name()`                     | `0x06fdde03` | none                                  |
| `allowance(address,address)` | `0xdd62ed3e` | owner (32 bytes) + spender (32 bytes) |

### Get the current block number

```bash theme={null}
curl -X POST https://rpc.polynode.dev \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'
```

### Get a transaction receipt

```bash theme={null}
curl -X POST https://rpc.polynode.dev \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getTransactionReceipt",
    "params": ["0xYOUR_TX_HASH"],
    "id": 1
  }'
```

## Batch Requests

Send multiple calls in a single HTTP request:

```bash theme={null}
curl -X POST https://rpc.polynode.dev \
  -H "Content-Type: application/json" \
  -H "x-api-key: YOUR_API_KEY" \
  -d '[
    {"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1},
    {"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":2},
    {"jsonrpc":"2.0","method":"eth_gasPrice","params":[],"id":3}
  ]'
```

Batch requests count as a single request against the rate limit.

## Error Codes

| Code     | Meaning                           |
| -------- | --------------------------------- |
| `-32000` | Missing or invalid API key        |
| `-32005` | Rate limit exceeded (max 2 req/s) |
| `-32601` | Method not available              |
| `-32602` | Invalid parameters                |
| `-32603` | Upstream error                    |