---
title: "Add a Multi Token minter"
method: POST
path: "/v3/multitoken/mint/add"
tags: ["Multi Tokens (ERC-1155 or compatible)"]
---

# Add a Multi Token minter

`POST /v3/multitoken/mint/add`

## Request

- Base URL: `https://api.tatum.io`
- URL: `https://api.tatum.io/v3/multitoken/mint/add`
- Auth: API key in header `x-api-key`

/v3/multitoken/mint/add

**2 credits per API call**

Add Multi Token minter.

This API is supported for the following blockchains:

*   BNB Smart Chain
*   Celo
*   Ethereum
*   Harmony
*   Klaytn
*   KuCoin Community Chain
*   Polygon
*   Flare
*   Cronos
*   Base
*   Avalanche
*   Fantom
*   Optimism

**Signing a transaction**

When adding a Multi Token minter, you are charged a fee for the transaction, and you must sign the transaction with the private key of the blockchain address from which the fee will be deducted.

Providing the private key in the API is not a secure way of signing transactions, because the private key can be stolen or exposed. Your private keys should never leave your security perimeter. You should use the private keys only for testing a solution you are building on the **testnet** of a blockchain.

For signing transactions on the **mainnet**, we strongly recommend that you use the Tatum [Key Management System (KMS)](https://github.com/tatumio/tatum-kms) and provide the signature ID instead of the private key in the API. Alternatively, you can use the [Tatum JavaScript client](https://github.com/tatumio/tatum-js/tree/v2).

## Query parameters

- `testnetType` 'ethereum-sepolia' | 'flare-coston' | 'flare-coston2' | 'flare-songbird': Specifies the testnet type. The default is ethereum-sepolia for Ethereum (ETH) currency and flare-coston for Flare (FLR) currency. Valid testnet types depend on the specified currency.

## Headers

- `x-testnet-type` Schema (unresolved $ref)

## Request body

- union
  - AddMultiTokenMinter
    - `chain` 'ETH' | 'MATIC' | 'KCS' | 'KLAY' | 'CELO' | 'ONE' | 'BSC' | 'FLR' | 'CRO' | 'BASE' | 'AVAX' | 'OPTIMISM' | 'FTM', required: Chain to work with.
    - `contractAddress` string, required: Address of MultiToken token
    - `minter` string, required: Address of MultiToken minter
    - `fromPrivateKey` string, required: Private key of sender address. Private key, or signature Id must be present.
    - `nonce` number: Nonce to be set to Ethereum transaction. If not present, last known nonce will be used.
    - `fee` CustomFee: The custom defined fee; if not present, will be calculated automatically
      - `gasPrice` string, required: The price for one gas unit (in Gwei)
      - `gasLimit` string, required: The maximum number of gas units that you are willing to spend on processing the transaction at the provided gas price
    - `feeCurrency` 'CELO' | 'CUSD' | 'CEUR': Currency to pay for transaction gas, only valid for CELO chain.
  - AddMultiTokenMinterKMS
    - `chain` 'ETH' | 'MATIC' | 'KCS' | 'KLAY' | 'CELO' | 'ONE' | 'BSC', required: Chain to work with.
    - `contractAddress` string, required: Address of MultiToken token
    - `minter` string, required: Address of MultiToken minter
    - `index` number: If signatureId is mnemonic-based, this is the index to the specific address from that mnemonic.
    - `signatureId` string, uuid, required: Identifier of the private key associated in signing application. Private key, or signature Id must be present.
    - `nonce` number: Nonce to be set to Ethereum transaction. If not present, last known nonce will be used.
    - `fee` CustomFee: The custom defined fee; if not present, will be calculated automatically
      - `gasPrice` string, required: The price for one gas unit (in Gwei)
      - `gasLimit` string, required: The maximum number of gas units that you are willing to spend on processing the transaction at the provided gas price
    - `feeCurrency` 'CELO' | 'CUSD' | 'CEUR': Currency to pay for transaction gas, only valid for CELO chain.

## Response `200`

OK

- union
  - TransactionHash
    - `txId` string, required: The hash (ID) of the transaction
  - SignatureId
    - `signatureId` string, uuid, required: The internal Tatum ID of the prepared transaction for Key Management Sysytem (KMS) to sign<br/>This is different from the <code>signatureId</code> parameter that you provided in the request body. The <code>signatureId</code> parameter in the request body specifies the signature ID associated with the private key in KMS.

## Other responses

- `400`: Bad Request
- `401`: Unauthorized. Not valid or inactive subscription key present in the HTTP Header.
- `403`: Forbidden. The request is authenticated, but it is not possible to required perform operation due to logical error or invalid permissions.
- `500`: Internal server error. There was an error on the server during the processing of the request.

---

[API](https://skmtc.dev/tatum/apis/smart-contracts.md) - [All operations](https://skmtc.dev/tatum/apis/smart-contracts/llms.txt) - [OpenAPI document](https://skmtc.dev/tatum/apis/smart-contracts/revisions/c0146043bb37?raw)