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# ZKType - TypeScript bindings for Circom circuits

**ZKType simplifies and makes user-friendly the process of working with Circom circuits.**

- Generate a typed [zkit](https://github.com/dl-solarity/zkit) wrapper for given circuits.
- Support for `groth16` and `plonk` proving systems.
- Ensure that all inputs and proofs are correctly formatted.
- Typization for witness signals substitution.

## Installation

To install the package, run:

```bash
npm install --save-dev @solarity/zktype
```

## Usage

> [!IMPORTANT]
> ZKType is not meant to be used directly as its fitness relies heavily on the environment, e.g., on Circom compilation artifacts management. Consider using [hardhat-zkit](https://github.com/dl-solarity/hardhat-zkit), which is a complete, developer-friendly package.

### CircuitTypesGenerator

`CircuitTypesGenerator` is an entry point for generating TypeScript bindings for a given circuit.

To create a `CircuitTypesGenerator` object, it is necessary to pass a config:

```typescript
ZKTypeConfig = {
  basePath: "circuits",
  projectRoot: process.cwd(),
  circuitsArtifacts: [
    {
      artifactPath: "circuits/auth/Matrix_artifacts.json",
      circuitProtocolType: ["groth16"],
    },
  ],
  outputTypesDir: "generated-types/circuits", 
  signalNamesTypeLimit: 50000,
}
```

This config contains all the information required to generate TypeScript bindings for given circuits.

- `basePath` - Path to the root directory of the project where circuits are stored.
- `projectRoot` - Absolute path to the root directory of the project.
- `circuitsArtifacts` - Array of object containing the path to the circuit artifact and the protocol type of the circuit.
- `outputTypesDir` - Path to the directory where the generated types will be stored.
    - Optional. Default: `generated-types/circuits`.
- `signalNamesTypeLimit` - Maximum number of signals allowed to generate a `SignalNames` union type for the circuit.
    - Optional. Default: 50000.

#### API reference

---

- **`async generateTypes()`**

Generates TypeScript bindings for the given circuits, based on the provided config.

```typescript
const generator = new CircuitTypesGenerator(config);

await generator.generateTypes();
```

Also, this function generates the `hardhat.d.ts` file, where you can find all the possible objects that can be retrieved by the function below.

- **`async getCircuitObject(circuitName: string, protocolType?: string): Promise<any>`**

Returns the constructible object for the given circuit.

```typescript
const generator = new CircuitTypesGenerator(config);

await generator.generateTypes();

const circuitObject = await generator.getCircuitObject("MyCircuit", "groth16");
```

The package supports generation of circuits by the `groth16` and `plonk` protocols at the same time. 
In this case, you will have to specify the protocol type when retrieving the object.

After the `circuitObject` is retrieved, check out the [zkit](https://github.com/dl-solarity/zkit) documentation to see how to work with it.

To ensure that the object can be imported, check the `hardhat.d.ts` file.