# Gelato Web3 Functions

## Overview

Gelato's Web3 Functions is a powerful automation system designed to streamline and enhance Web3 operations. Web3 Functions serve as a comprehensive tool, enabling developers to effortlessly set up, manage, and automate their smart contract tasks. Determining your Needs

**Off-chain Data or Computation?** Sometimes, automation tasks require data that isn't readily available on the blockchain, or they might need computations that are better performed off-chain. In such cases, Typescript Functions should be the choice.

**All Checks On-chain?** If all the conditions necessary for your automation task can be directly verified on the blockchain, you have the option to select between Typescript Functions, Solidity Functions & Automated Transactions

## Triggers

1. Time Interval Description: Use this trigger to execute tasks at regular intervals, e.g., every 10 minutes or once every 24 hours. It's like setting a straightforward, recurring alarm.
2. Cron Expressions Description: This offers a more refined control compared to the Time Interval. With cron expressions, you can set tasks to run at specific moments, such as "every Tuesday at 3 PM" or "on the 1st of every month". It gives you precision in task scheduling.
3. On-Chain Event Description: Ideal for those wanting their tasks to respond dynamically to blockchain activities. Whenever a specified event occurs on the blockchain, this trigger springs your task into action. It's like a vigilant watcher, always ready to act.
4. Every Block Description: This function operates with the rhythm of the blockchain itself, executing your chosen function each time a new block is created.

## What to Execute?

### Typescript Functions

Typescript Functions are decentralized cloud functions that work similarly to AWS Lambda or Google Cloud, just for web3. They enable developers to execute on-chain transactions based on arbitrary off-chain data (APIs / subgraphs, etc) & computation. These functions are written in Typescript, stored on IPFS and run by Gelato.

### Solidity Functions

Solidity Functions are crucial for making on-chain tasks automatic and more efficient. They connect set conditions with specific actions in a smart contract, providing a straightforward method to turn user needs into automated processes. Consider them as a set of "if-then" rules: If certain conditions are met on the blockchain, then a specific function gets executed. This level of automation ensures that the decentralized application can operate with minimal manual intervention, providing a seamless user experience.

### Automated Transaction

Automated Transaction ensures that a specific function on the target smart contract gets reliably triggered. When you pre-define the inputs, it means that every time Gelato initiates the function call, it uses consistent, predetermined arguments.

## Quick Start

### Writing & Deploying Typescript Functions

1. Clone the hardhat-template repo

```shell
git clone web3-functions-hardhat-template
```

2. CD into the folder and install

```shell
cd web3-functions-hardhat-template && yarn install
```

3. Update the `index.ts` in one of the examples

```typescript
Web3Function.onRun(async (context: Web3FunctionContext) => {
  const { userArgs, multiChainProvider } = context;

  const provider = multiChainProvider.default();
  // Retrieve Last oracle update time
  const oracleAddress =
    (userArgs.oracle as string) ?? "0x71B9B0F6C999CBbB0FeF9c92B80D54e4973214da";

  // YOUR CUSTOM LOGIC
  .....

  // Return if nothing has to be pushed on-chain
    return { canExec: false, message: `Coingecko call failed` };

  // Return if tx has to be pushed on-chain
  return {
    canExec: true,
    callData: [
      {
        to: oracleAddress,
        data: oracle.interface.encodeFunctionData("updatePrice", [price]),
      },
    ],
  };
});
```

4. Deploy the Web3 Function to IPFS and create the Task

```shell
npx w3f deploy web3-functions/YOUR-FUNCTION/index.ts
```

Result:

```shell
$ npx w3f deploy web3-functions/YOUR-FUNCTION/index.ts
 ✓ Web3Function deployed to ipfs.
 ✓ CID: QmYMysfAhYYYrdhVytSTiE9phuoT49kMByktXSbVp1aRPx

To create a task that runs your Web3 Function every minute, visit:
> https://beta.app.gelato.network/new-task?cid=QmYMysfAhYYYrdhVytSTiE9phuoT49kMByktXSbVp1aRPx
✨  Done in 3.56s.
```

Finally, go to the [Gelato App](https://beta.app.gelato.app), create a new task, decide on the trigger, and input the CID.

<figure><img src="https://content.gitbook.com/content/Au0D0cnqYXeowSVawC8I/blobs/vKsKaHFO5nbbjPAZA0dt/image.png" alt=""><figcaption></figcaption></figure>

### Writing & Deploying Solidity Functions

The central part of a solidity function is the **Checker**. A Checker acts as a bridge between conditions and smart contract executions. Its purpose? To check conditions and determine whether a task should be executed by Gelato. Every checker returns two main things:

* canExec (Boolean): Indicates if Gelato should execute the task.
* execData (Bytes): Contains the data that executors will use during execution.

Once you have deployed your checker, go to the [Gelato App](https://beta.app.gelato.app), create a new task, decide the trigger, and input the address of the checker contract and the method that does the check.