1# Solidity verifier
 2
 3Having used the `Decider` from `decider_eth.rs`, we can now verify it in Ethereum's EVM.
 4
 5This can be done either by using the `solidity-verifiers-cli` or directly in rust code.
 6
 7## Using the CLI to generate the Solidity verifier
 8Use the [solidity-verifiers-cli](https://github.com/privacy-scaling-explorations/sonobe/tree/main/cli) tool
 9```
10> solidity-verifier-cli -p nova-cyclefold -d ./folding-verifier-solidity/assets/G16_test_vk_data
11```
12
13## Generating the Solidity verifier in rust
14Assuming that we already have our `Decider` initialized, we can now 
15
16
17```rust
18// prepare the call data
19let function_selector =
20    get_function_selector_for_nova_cyclefold_verifier(nova.z_0.len() * 2 + 1);
21let calldata: Vec<u8> = prepare_calldata(
22    function_selector,
23    nova.i,
24    nova.z_0,
25    nova.z_i,
26    &nova.U_i,
27    &nova.u_i,
28    proof,
29)
30.unwrap();
31
32// prepare the setup params for the solidity verifier
33let nova_cyclefold_vk = NovaCycleFoldVerifierKey::from((g16_vk, kzg_vk, f_circuit.state_len()));
34
35// generate the solidity code
36let decider_solidity_code = get_decider_template_for_cyclefold_decider(nova_cyclefold_vk);
37
38// verify the proof against the solidity code in the EVM
39let nova_cyclefold_verifier_bytecode = compile_solidity(&decider_solidity_code, "NovaDecider");
40let mut evm = Evm::default();
41let verifier_address = evm.create(nova_cyclefold_verifier_bytecode);
42let (_, output) = evm.call(verifier_address, calldata.clone());
43assert_eq!(*output.last().unwrap(), 1);
44
45// save smart contract and the calldata
46use std::fs;
47fs::write( "./examples/nova-verifier.sol", decider_solidity_code.clone()).unwrap();
48fs::write("./examples/solidity-calldata.calldata", calldata.clone()).unwrap();
49let s = solidity_verifiers::utils::get_formatted_calldata(calldata.clone());
50fs::write("./examples/solidity-calldata.inputs", s.join(",\n")).expect("");
51```
52
53You can find the full flow at [examples/full_flow.rs](https://github.com/privacy-scaling-explorations/sonobe/blob/main/examples/full_flow.rs).