# Running the Server

### Enable Server <a href="#enable-server" id="enable-server"></a>

To enable RPC server use the following flag (set to true by default).

```bash
blockxd start --json-rpc.enable
```

### Defining Namespaces <a href="#defining-namespaces" id="defining-namespaces"></a>

`Eth`,`Net` and `Web3` namespaces are enabled by default. In order to enable other namespaces use flag `--json-rpc.api`.

```bash
blockxd start --json-rpc.api eth,txpool,personal,net,debug,web3,miner
```

### Set a Gas Cap <a href="#set-a-gas-cap" id="set-a-gas-cap"></a>

`eth_call` and `eth_estimateGas` define a global gas cap over rpc for DoS protection. You can override the default gas cap value of 25,000,000 by passing a custom value when starting the node:

```bash
# set gas cap to 85M
blockxd start --json-rpc.gas-cap 85000000000

# set gas cap to infinite (=0)
blockxd start --json-rpc.gas-cap 0
```

### CORS <a href="#cors" id="cors"></a>

If accessing the RPC from a browser, CORS will need to be enabled with the appropriate domain set. Otherwise, JavaScript calls are limit by the same-origin policy and requests will fail.

The CORS setting can be updated from the `app.toml`:

```
###############################################################################
###                           API Configuration                             ###
###############################################################################

[api]

# ...

# EnableUnsafeCORS defines if CORS should be enabled (unsafe - use it at your own risk).
enabled-unsafe-cors = true # default false
```