## Bundler

The Bundler makes first time sign up easier by allowing a user to register an fid, add a key and rent storage in one transaction. If you want to create a new Farcaster account in a single transaction, use the Bundler.

## Read

### Price

Get the price in wei to register an fid, including 1 storage unit. To add additional storage units to the calculation, use the `extraStorage` parameter.

| Parameter      | type     | Description                                         |
|----------------|----------|-----------------------------------------------------|
| extraStorage   | `uint256`| Number of extra units to include in the price     |

## Write

### Register

Register an fid, add one or more keys, and rent storage in a single step. For a detailed usage example, see the [signup demo app](https://farcaster-signup-demo.vercel.app/bundler).

| Parameter       | type             | Description                                                       |
|-----------------|------------------|-------------------------------------------------------------------|
| `msg.value`     | `wei`           | Payment amount for registration                                   |
| registerParams   | `RegistrationParams` | Registration related parameters and signature               |
| signerParams    | `SignerParams[]`| Key related parameters and signature                              |
| extraStorage     | `uint256`      | Additional storage units to rent                                 |

**RegistrationParams struct** The `RegistrationParams` struct includes registration parameters and an IdGateway [`Register`](https://docs.neynar.com/farcaster/reference/contracts/reference/id-gateway#register-signature) signature from the fid recipient.

| Parameter     | type     | Description                                                                            |
|---------------|----------|----------------------------------------------------------------------------------------|
| to            | `address`| Address to register the fid to                                                        |
| recovery      | `address`| Recovery address for the new fid                                                      |
| deadline      | `uint256`| Signature expiration timestamp                                                         |
| sig           | `bytes`  | EIP-712 [`Register`](https://docs.neynar.com/farcaster/reference/contracts/reference/id-gateway#register-signature) signature from the `to` address |

**SignerParams struct** The `SignerParams` struct includes signer key parameters and a KeyGateway [`Add`](https://docs.neynar.com/farcaster/reference/contracts/reference/key-gateway#add-signature) signature from the fid recipient. Callers may provide multiple `SignerParams` structs to add multiple keys at registration time.

| Parameter       | type     | Description                                                         |
|-----------------|----------|---------------------------------------------------------------------|
| keyType         | `uint32` | Must be set to `1`. This is currently the only supported `keyType`. |
| key             | `bytes`  | Public key to add                                                   |
| metadataType    | `uint8`  | Must be set to `1`. This is currently the only supported `metadataType`. |
| metadata        | `bytes`  | Encoded [`SignedKeyRequestMetadata`](https://docs.neynar.com/farcaster/reference/contracts/reference/signed-key-request-validator#signedkeyrequestmetadata-struct) |
| deadline        | `uint256`| Signature expiration timestamp                                        |
| sig             | `bytes`  | EIP-712 [`Add`](https://docs.neynar.com/farcaster/reference/contracts/reference/key-gateway#add-signature) signature from `registrationParams.to` address |

## Errors

| Error           | Selector    | Description                                                              |
|----------------|-------------|---------------------------------------------------------------------------|
| InvalidPayment  | `3c6b4b28`  | The caller provided insufficient payment.                                |
| InvalidMetadata  | `bcecb64a`  | The signed metadata provided with the key is invalid.                   |
| InvalidSignature | `8baa579f`  | The provided signature is invalid. It may be incorrectly formatted, or signed by the wrong address. |
| SignatureExpired | `0819bdcd`  | The provided signature has expired. Collect a new signature from the signer with a later deadline timestamp. |

## Source

[`Bundler.sol`](https://github.com/farcasterxyz/contracts/blob/1aceebe916de446f69b98ba1745a42f071785730/src/Bundler.sol)