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

# JSON-RPC reference

> Connect to a Quantum Chain node and call the qc_* JSON-RPC namespace

The Quantum Chain node exposes a standard **JSON-RPC 2.0** interface over HTTP and WebSocket. All methods in the Ethereum `eth_*` namespace are also available under the `qc_*` namespace. The `qc_*` variant is recommended for Quantum Chain integrations.

<Note>
  Every `qc_*` method has an identical `eth_*` counterpart. If your tooling only supports `eth_*`, it works the same way.
</Note>

## Connecting

**HTTP**

```bash theme={null}
curl -X POST https://api.quantumapi.io/v1/rpc \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"qc_blockNumber","params":[],"id":1}'
```

**WebSocket**

```bash theme={null}
wscat -c wss://api.quantumapi.io/v1/rpc
> {"jsonrpc":"2.0","method":"qc_blockNumber","params":[],"id":1}
```

## Enabling RPC modules

By default, the node only exposes `net` and `web3` modules. Enable additional modules with CLI flags:

```bash theme={null}
geth --http --http.api eth,qc,net,web3,txpool --ws --ws.api eth,qc,net,web3
```

## Namespaces

| Namespace  | Description                                                          |
| ---------- | -------------------------------------------------------------------- |
| `qc`       | Quantum Chain native: accounts, blocks, transactions, gas, execution |
| `eth`      | Ethereum-compatible alias (identical to `qc`)                        |
| `net`      | Network info: peer count, version, listening status                  |
| `web3`     | Utilities: client version, SHA3                                      |
| `txpool`   | Transaction pool inspection                                          |
| `debug`    | Debugging and tracing                                                |
| `admin`    | Node administration and peer management                              |
| `personal` | Account management (unlock, sign)                                    |

## Request format

Every request follows JSON-RPC 2.0:

```json theme={null}
{
  "jsonrpc": "2.0",
  "method": "qc_blockNumber",
  "params": [],
  "id": 1
}
```

## Block number tags

Several methods accept a block identifier instead of a number:

| Tag           | Meaning                     |
| ------------- | --------------------------- |
| `"latest"`    | Most recent mined block     |
| `"pending"`   | Pending state/transactions  |
| `"earliest"`  | Genesis block               |
| `"finalized"` | Most recent finalized block |
| `"safe"`      | Most recent safe block      |

## Reference pages

<CardGroup cols={2}>
  <Card title="Blocks" icon="cube" href="/rpc-reference/blocks">
    Chain ID, block number, headers, block lookups, uncle queries
  </Card>

  <Card title="Accounts" icon="wallet" href="/rpc-reference/accounts">
    Balances, code, storage, proofs, receipts
  </Card>

  <Card title="Transactions" icon="arrow-right-arrow-left" href="/rpc-reference/transactions">
    Send, query, sign, receipts, pending pool
  </Card>

  <Card title="Gas & fees" icon="gas-pump" href="/rpc-reference/gas-fees">
    Gas price, priority fee, fee history, estimation
  </Card>

  <Card title="Execution" icon="play" href="/rpc-reference/execution">
    Read-only calls, access lists, sync status
  </Card>
</CardGroup>