# `GM! 🤠` In this tutorial we'll make a very simple consumer contract called `SaysGm`. All this contract does is request compute from our `hello-world` container and upon receiving a response, it prints everything to the console. > [!NOTE] > Run this tutorial in a new directory, the end result of this tutorial will > be pretty much the same as the [contracts](.) project, so refer to that if > you get stuck. ## Prerequisites ### Installing foundry You'll need [foundry](https://book.getfoundry.sh/getting-started/installation) installed. ### Scaffolding a new project Create a new directory, and run `forge init` in it. This will create a new project with a `foundry.yaml` file in it. ```bash mkdir says-gm cd says-gm forge init ``` ### Installing Infernet sdk Install our Infernet SDK via forge. ```bash forge install ritual-net/infernet-sdk ``` ### Specifying remappings Create a new file called `remappings.txt` in the root of your project. ``` forge-std/=lib/forge-std/src infernet-sdk/=lib/infernet-sdk/src ``` This'll make it easier to import our dependencies. More explanation on remappings [here](https://book.getfoundry.sh/projects/dependencies?highlight=remappings#remapping-dependencies). ### `SaysGm` contract Under the `src/` directory, create a new file called `SaysGm.sol` with the following content: ```solidity // SPDX-License-Identifier: BSD-3-Clause-Clear pragma solidity ^0.8.13; import {console2} from "forge-std/console2.sol"; import {CallbackConsumer} from "infernet-sdk/consumer/Callback.sol"; contract SaysGM is CallbackConsumer { constructor(address registry) CallbackConsumer(registry) {} function sayGM() public { _requestCompute( "hello-world", bytes("Good morning!"), 20 gwei, 1_000_000, 1 ); } function _receiveCompute( uint32 subscriptionId, uint32 interval, uint16 redundancy, address node, bytes calldata input, bytes calldata output, bytes calldata proof ) internal override { console2.log("\n\n" "_____ _____ _______ _ _ _\n" "| __ \\|_ _|__ __| | | | /\\ | |\n" "| |__) | | | | | | | | | / \\ | |\n" "| _ / | | | | | | | |/ /\\ \\ | |\n" "| | \\ \\ _| |_ | | | |__| / ____ \\| |____\n" "|_| \\_\\_____| |_| \\____/_/ \\_\\______|\n\n"); console2.log("subscription Id", subscriptionId); console2.log("interval", interval); console2.log("redundancy", redundancy); console2.log("node", node); console2.log("input:"); console2.logBytes(input); console2.log("output:"); console2.logBytes(output); console2.log("proof:"); console2.logBytes(proof); } } ``` All this contract does is request compute from our `hello-world` container via the `_requestCompute` function. An Infernet node will pick up this subscription, execute the compute, and deliver the result to our contract via the `_receiveCompute` function. ### Adding a Deploy Script In the `scripts` directory, add a new file called `Deploy.s.sol`: ```solidity // SPDX-License-Identifier: BSD-3-Clause-Clear pragma solidity ^0.8.13; import {Script, console2} from "forge-std/Script.sol"; import {SaysGM} from "../src/SaysGM.sol"; contract Deploy is Script { function run() public { // Setup wallet uint256 deployerPrivateKey = vm.envUint("PRIVATE_KEY"); vm.startBroadcast(deployerPrivateKey); // Log address address deployerAddress = vm.addr(deployerPrivateKey); console2.log("Loaded deployer: ", deployerAddress); address registry = 0x663F3ad617193148711d28f5334eE4Ed07016602; // Create consumer SaysGM saysGm = new SaysGM(registry); console2.log("Deployed SaysHello: ", address(saysGm)); // Execute vm.stopBroadcast(); vm.broadcast(); } } ``` The coordinator address is the address of the Infernet coordinator. Our Infernet Anvil Node already has `Coordinator` pre-deployed to that address. ### Adding a Call Script Create another file under the `script` directory called `CallContract.s.sol` ```solidity // SPDX-License-Identifier: BSD-3-Clause-Clear pragma solidity ^0.8.0; import {Script, console2} from "forge-std/Script.sol"; import {SaysGM} from "../src/SaysGM.sol"; contract CallContract is Script { function run() public { // Setup wallet uint256 deployerPrivateKey = vm.envUint("PRIVATE_KEY"); vm.startBroadcast(deployerPrivateKey); SaysGM saysGm = SaysGM(0x13D69Cf7d6CE4218F646B759Dcf334D82c023d8e); saysGm.sayGM(); vm.stopBroadcast(); } } ``` ### Building the Project Before building our project, we'll need to add this line to the `foundry.toml` file: ``` via_ir = true ``` So your `foundry.toml` file should look like [this](./foundry.toml). Otherwise the compiler will complain about stack too deep errors. Now, let's build our project. ```bash forge build ``` The project should build successfully. ### Deploying the Contracts **Deploy Infernet** To deploy our contracts, and later be able to call and test them, we'll need to deploy infernet, as well as our `hello-world` container! Refer to [the readme at the root of this project](../../README.md) for instructions on how to do that. After deploying an Infernet Node locally, we'll need to run the `Deploy` script. ```bash PRIVATE_KEY=0x5de4111afa1a4b94908f83103eb1f1706367c2e68ca870fc3fb9a804cdab365a \ forge script script/Deploy.s.sol:Deploy --broadcast \ --rpc-url http://localhost:8545 ``` The private key here is anvil's anvil's third default address which contains 10000 ETH. ### Calling the Contract Similarly, to run our `CallContract.s.sol` script, we'll invoke it with `forge script`: ```bash PRIVATE_KEY=0x5de4111afa1a4b94908f83103eb1f1706367c2e68ca870fc3fb9a804cdab365a \ forge script script/CallContract.s.sol:Deploy --broadcast \ --rpc-url http://localhost:8545 ``` ### Using a `Makefile` To make running these commands easier, we can add them to a `Makefile`. This allows us to run `make deploy` and `make call` instead of typing out the full command every time. Refer to [this project's Makefile](./Makefile) for an example. ### 🎉 Done! Congratulations! You've successfully created a contract that requests compute from our `hello-world` container.