docs: prover network usage (#647)

book/generating-proofs/network.md

@@ -0,0 +1,47 @@
+# Generating Proofs: Prover Network
+
+In the case that you do not want to prove locally, you can use the Succinct prover network to generate proofs.
+
+**Note:** The network is still in development and should be only used for testing purposes.
+
+## Sending a proof request
+
+To use the prover network to generate a proof, you can run your program as you would normally but with additional environment variables set:
+
+```sh
+SP1_PROVER=network SP1_PRIVATE_KEY=... cargo run --release
+```
+
+- `SP1_PROVER` can be set to `network` or `local`, and defaults to local.
+
+- `SP1_PRIVATE_KEY` is your secp256k1 private key for signing messages on the network. The balance of
+  the address corresponding to this private key will be used to pay for the proof request.
+
+Once a request is sent, a prover will claim the request and start generating a proof. After some
+time, it will be returned.
+
+## Network balance
+
+Before sending requests, you must ensure you have enough balance on the network. You can add to your
+balance by sending ETH to the canonical `NetworkFeeVault` contract on Base, which has the address
+[0x66ea36fDBdDD09E3aCAB7B9f654220B00e537574](https://basescan.org/address/0x66ea36fdbddd09e3acab7b9f654220b00e537574#code).
+
+Adding to your balance can be done in [Etherscan](https://basescan.org/address/0x66ea36fdbddd09e3acab7b9f654220b00e537574#writeContract) by
+connecting your wallet, or by using the [cast](https://book.getfoundry.sh/cast/) CLI tool.
+
+This can be done either by calling the `addBalance()` function:
+
+```sh
+# The sender will send 1000 wei and the $OWNER will have their balance increased by 1000
+OWNER=(your address)
+AMOUNT=1000
+cast send 0x66ea36fDBdDD09E3aCAB7B9f654220B00e537574 "addBalance(address)" $OWNER --value $AMOUNT --private-key $PRIVATE_KEY --chain-id 8453 --rpc-url https://developer-access-mainnet.base.org
+```
+
+or by sending ETH directly:
+
+```sh
+# The sender will send 1000 wei and have their balance increased by 1000
+AMOUNT=1000
+cast send 0x66ea36fDBdDD09E3aCAB7B9f654220B00e537574 --value $AMOUNT --private-key $PRIVATE_KEY --chain-id 8453 --rpc-url https://developer-access-mainnet.base.org
+```