Overview

The Upgradeable ERC-1155F smart contract template by Fireblocks can be used to issue ERC-1155 semi-fungible tokens (SFTs). Similar to ERC-721, each token is represented by a contract address and a TokenID. However, unlike ERC-721, each TokenID may have an amount that represents the number of similar tokens that share the same attributes.

This token contract works seamlessly with your Fireblocks workspace and can be used to:

• Create unique NFTs like in-game items, digital collectibles, and tokenized assets.
• Represent multiple tokens with a single contract.
• Reduce deployment costs by bundling multiple token types.

The contract is considered upgradeable since it is deployed as an implementation contract and a proxy contract, which points to the latest implementation. Learn more.

This article describes several common operations you can use for smart contracts deployed from this template.

Deploying

When deploying smart contracts using the Upgradeable ERC-1155F template, make sure to enter the addresses you want for the Default Admin, Minter, and Pauser roles. You can treat your deployed contract as a collection since you can use it to mint multiple unique NFTs.

Learn more about smart contract roles.

Minting

Before minting tokens, the Minter role must be granted to an address. A Minter role is assigned during deployment as mentioned in the previous section. However, the Default Admin role can assign additional Minter roles after the contract has been deployed.

1. On the Tokenization page, select More Actions (...) > Manage contract corresponding to the relevant smart contract.
2. Copy the Minter role hash from the Read functions.
3. Select Write and use the grantRole function.
4. Enter the hash for the Minter role you copied in step 2, and then enter the address that should be granted the role.
5. Select Submit.

After the Minter role is granted, any address with the Minter role can mint NFTs from your deployed contract by using the mint function.

1. On the Tokenization page, select More Actions (...) > Manage contract corresponding to the relevant smart contract.
2. Select Write and use the mint function.
3. Select the source vault account.
4. Enter the address where you want to receive the NFT.
5. Enter a token ID for the SFT.
6. Enter the link to the token metadata, such as an image, in the Uri field.
   • Only links entered during the first mint of each TokenID will be stored in the smart contract. Upon subsequent mints of the TokenID, you will be unable to store data using this field.
7. Enter 0x in the Data field.
   • This parameter stores arbitrary data on-chain when minting ERC-1155 tokens. Since this field is not optional and must be formatted correctly, entering 0x allows you to pass this parameter as an empty value and complete the mint function.
8. Select Submit.

If the NFT was sent to a vault account in Fireblocks, it will appear in the NFT Gallery.

Batch minting

You can also mint a batch of new ERC-1155 tokens at once by using the mintBatch function instead of the mint function. When batch minting, you can input multiple values in each field by selecting the Enter key after each value.

Burning

Before burning tokens, the Burner role must be granted to an address. Only the Default Admin role can assign the Burner role to an address.

1. On the Tokenization page, select More Actions (...) > Manage contract corresponding to the relevant smart contract.
2. Copy the Burner role hash from the Read functions.
3. Select Write and use the grantRole function.
4. Enter the hash for the Burner role you copied in step 2, and then enter the address that should be granted the role.
5. Select Submit.

After the Burner role is granted, the address with the Burner role can burn tokens by using the burn function when managing the smart contract.

Updating NFT metadata

Your NFT’s metadata, often a form of media, can be added when minting the token. You can also add or update the metadata later by using the tokenUriUpdate function.

Contract metadata (contractURI)

You can add and manage the metadata linked to your smart contract by using the contractUriUpdate function. For example, you may want to link your ERC-1155 token to a Terms of Service, an Investment Offering, or other important documentation. We provide the Contract URI field so you can store links on the smart contract.

To store a link on the smart contract, we provide the Contract URI field where you can add those links.

First, you need to grant someone the Contract Admin role for the smart contract.

1. On the Tokenization page, select More Actions (...) > Manage contract corresponding to the relevant smart contract.
2. Copy the Contract Admin role hash from the Read functions.
3. Select Write and use the grantRole function.
4. Enter the hash for the Contract Admin role you copied in step 2, and then enter the address that should be granted the role.
5. Select Submit.

At this point, the user granted the Contract Admin role can access the smart contract and add the link as metadata.

1. On the Tokenization page, select More Actions (...) > Manage contract corresponding to the relevant smart contract.
2. Select Write and use the contractUriUpdate function.
3. Enter the link to the metadata in the Uri field.
4. Select Submit.

Token recovery

If an ERC-1155F contract is used in conjunction with a Fireblocks Allowlist or Denylist, token recovery is made available. When a user holds tokens but fails the Allowlist or Denylist test, those tokens can be clawed back and returned to the smart contract.

First, you need to grant someone the Recovery role for the smart contract.

1. On the Tokenization page, select More Actions (...) > Manage contract corresponding to the relevant smart contract.
2. Copy the Recovery role hash from the Read functions.
3. Select Write and use the grantRole function.
4. Enter the hash for the Recovery role you copied in step 2, and then enter the address that should be granted the role.
5. Select Submit.

At this point, the user granted the Recovery role can recover those tokens.

1. On the Tokenization page, select More Actions (...) > Manage contract corresponding to the relevant smart contract.
2. Select Write and use the recoverTokens function.
3. Enter the address currently holding the tokens and the amount of tokens to recover.
4. Select Submit.

Salvage

If a token not associated with your ERC-1155F contract is accidentally transferred to it, the token will be stuck since the contract has no governance over it. You can use the Salvage role to send those external tokens back to the address that originally sent them.

First, you need to grant someone the Salvage role for the smart contract.

1. On the Tokenization page, select More Actions (...) > Manage contract corresponding to the relevant smart contract.
2. Copy the Salvage role hash from the Read functions.
3. Select Write and use the grantRole function.
4. Enter the hash for the Salvage role you copied in step 2, and then enter the address that should be granted the role.
5. Select Submit.

At this point, the user granted the Salvage role can send back the tokens.

1. On the Tokenization page, select More Actions (...) > Manage contract corresponding to the relevant smart contract.
2. Select Write and use the Salvage ERC1155 function.
3. Enter the address currently holding the tokens and the amount of tokens to send back.
4. Select Submit.

Connect an Allowlist/Denylist

You can connect either an Allowlist or Denylist token utility contract to your ERC-1155F contract. Token contracts can only be connected to a single Allowlist or Denylist. You cannot connect both to the same token contract. Learn more about our token utility contracts and how to create them.

First, you need to grant someone the Contract Admin role for the smart contract.

1. In the Fireblocks Console, go to the Tokenization page and select More Actions (...) > Manage contract for the ERC-1155F contract you want the Allowlist connected to.
2. Copy the Contract Admin role hash from the Read functions.
3. Select Write and use the grantRole function.
4. Enter the hash for the Contract Admin role you copied in step 2, and then enter the address that should be granted the role.
5. Select Submit.

At this point, the user granted the Contract Admin role can access the smart contract and connect the Allowlist or Denylist.

1. On the Tokenization page, copy the address to the Allowlist or Denylist.
2. Select More Actions (...) > Manage contract corresponding to the relevant smart contract.
3. Select Write and use the accessRegistryUpdate() function.
4. Enter the address to the Allowlist or Denylist in the Access registry field.
5. Select Submit.

Pausing/Unpausing

If needed, you can completely pause the contract from functioning. This may be useful if you believe the contract has been compromised. After resolving any security implications, you can then unpause the contract to resume functionality.

Only the following functions can be called while the contract is paused:

• revokeRole
• renounceRole
• upgradeToAndCall
• salvageERC20
• salvageGas
• initialize
• grantRole
• version
• supportsInterface
• contractUriUpdate

To pause the contract, you must first grant someone the Pauser role for the smart contract.

1. On the Tokenization page, select More Actions (...) > Manage contract corresponding to the relevant smart contract.
2. Copy the Pauser role hash from the Read functions.
3. Select Write and use the grantRole function.
4. Enter the hash for the Pauser role you copied in step 2, and then enter the address that should be granted the role.
5. Select Submit.

At this point, the user granted the Pauser can pause and unpause the contract as needed.

1. On the Tokenization page, select More Actions (...) > Manage contract corresponding to the relevant smart contract.
2. Select Write and use the pause() or unpause() function.
3. Select the vault account containing the address assigned the Pauser role.
4. Select Submit.

Audit report

• Upgradeable ERC-1155F contract audit report by OpenZeppelin