4.3 ERC-1155: The Multi-Token Standard

The ERC-1155 standard emerged as a direct response to the inefficiencies of its predecessors, offering a more powerful and versatile framework for managing digital assets on the Ethereum blockchain. Developed by the team at Enjin, a company focused on blockchain gaming, ERC-1155 was conceived to handle the complex requirements of modern decentralized applications, which often need to manage a wide variety of both unique and interchangeable items. Proposed as EIP-1155, it introduced a "multi-token" model that allows a single smart contract to govern an essentially infinite number of different token types, fundamentally changing the economics and logistics of token management on Ethereum.[1]

Motivation and Design Philosophy

The core motivation behind ERC-1155 was to overcome the limitations of maintaining separate contracts for fungible (ERC-20) and non-fungible (ERC-721) tokens. In a typical blockchain game, for example, a developer would need to deploy an ERC-20 contract for in-game currency, and a separate ERC-721 contract for each type of unique item (e.g., swords, armor, special characters). This approach was not only costly, requiring multiple contract deployments, but also fragmented the game's assets and created complexity for users, who would have to approve interactions with each contract individually.[2]

ERC-1155's design philosophy is one of unification and efficiency. It establishes a single, standardized contract interface that can represent any number of tokens, whether they are:

• Fungible: Interchangeable items like gold coins or crafting materials.

• Non-Fungible: Unique, one-of-a-kind items like a legendary sword or a specific plot of virtual land.

• Semi-Fungible: A new category introduced by the standard. These tokens are fungible within their class (e.g., 100 identical concert tickets for Section A) but are not interchangeable with tokens of another class (e.g., tickets for Section B). They can also possess properties that change over time; for instance, a concert ticket is fungible before the event but can become a unique, non-fungible collectible afterward.

By consolidating all of a project's assets into one smart contract, ERC-1155 dramatically reduces deployment costs, simplifies asset management, and enhances transactional efficiency.

Core Innovations and Technical Architecture

Unified Contract and Token IDs

The most significant architectural shift is the use of a single contract to manage multiple token types. Instead of a contract representing a single collection, an ERC-1155 contract acts as a master registry for all of a project's assets. Within this contract, each distinct class of asset is identified by a unique tokenId. The contract tracks the balance of each tokenId for every owner address.

• For a non-fungible token, the contract would mint a supply of exactly 1 for a specific tokenId.

• For a fungible token, the contract would mint a large supply (e.g., 1,000,000) for a different tokenId.

• For a semi-fungible token, the contract could mint a limited supply (e.g., 100) for another tokenId.

This design means that ownership is represented as mapping(address => mapping(uint256 => uint256)), which maps an owner's address to their balance for each specific tokenId.

Batch Operations

The flagship feature of ERC-1155 is its native support for batch operations, which allows multiple types of tokens to be managed in a single atomic transaction. This provides enormous gas savings and a superior user experience.

• balanceOfBatch(address calldata accounts, uint256 calldata ids): This function allows a dApp to query the balances of multiple token types for multiple addresses in a single on-chain call, which is far more efficient than making individual balanceOf calls for each token and address.

• safeBatchTransferFrom(address from, address to, uint256 calldata ids, uint256 calldata amounts, bytes calldata data): This is the standard's most powerful function. It enables a user to transfer multiple different assets—for example, 100 gold coins (id: 1, amount: 100), 5 health potions id: 2, amount: 5), and one unique sword (id: 3, amount: 1)—to another user in a single transaction. This consolidation drastically reduces the gas fees and network congestion that would result from executing three separate transfers under the old standards.

Safe Transfers and Hooks

Building on the safety mechanism introduced in ERC-721, ERC-1155 mandates safe transfer rules to prevent the accidental loss of assets. When tokens are sent to a smart contract address, the recipient contract must implement a receiver interface (IERC1155Receiver) and return a specific magic value to acknowledge that it can accept the tokens. If the recipient contract does not support this interface or rejects the transfer, the entire transaction reverts, ensuring the sender's tokens are never locked in an incompatible contract.

Metadata Handling

ERC-1155 also optimizes metadata management. Instead of requiring a unique URI for every single non-fungible token, the standard uses a single uri(uint256 _id) function. This function typically returns a base URI string that includes a {id} placeholder. Wallets and marketplaces are expected to replace this placeholder with the specific token ID (formatted as a hex string) to construct the final URI for fetching the metadata JSON file. This approach is more efficient for collections with many tokens, as it avoids storing redundant URI data on-chain.

Dominant Use Cases

• Blockchain Gaming: ERC-1155 is the de facto standard for the gaming industry. It provides the perfect framework for managing complex in-game economies that include fungible currencies (e.g., gold, mana), semi-fungible consumables (e.g., potions, scrolls), and unique non-fungible assets (e.g., characters, weapons, land) all within a single, efficient contract. Major blockchain games like The Sandbox and Gods Unchained leverage this standard to power their asset ecosystems.[3]

• Digital Art and Editions: Artists and platforms can use ERC-1155 to issue a unique 1-of-1 masterpiece as an NFT while simultaneously offering a limited series of prints as semi-fungible tokens, all managed by the same contract.[4]

• Decentralized Finance (DeFi): The standard is well-suited for representing complex financial instruments. For example, it can be used to tokenize real estate, where a unique NFT represents the property deed, and a set of fungible tokens represents fractional shares of ownership in that property.[5]

Token Comparison

Feature	ERC-20	ERC-721	ERC-1155
Token type	Fungible	Non-fungible	Both fungible and non-fungible
Single contract	Single token	Single token	Multiple token types
Batch transfers	No	No	Yes
Gas efficiency	Low	Low	High
Use cases	Cryptocurrencies	NFTs (art, collectibles)	Games, DeFi, mixed-token use cases

Taken from CoinTracker

References

[1] Alchemy - "Your Guide to ERC-1155: Comparing ERC-721 to ERC-1155" - https://www.alchemy.com/blog/comparing-erc-721-to-erc-1155

[2] Ethereum - "ERC-1155: Multi Token Standard" - https://eips.ethereum.org/EIPS/eip-1155

[3] Dcentwallet - "ERC-1155: A Revolutionary Leap in Blockchain Asset Management" - https://store.dcentwallet.com/blogs/post/erc-1155-a-revolutionary-leap-in-blockchain-asset-management

[4] Risein - "Introduction to the ERC-1155 Token Standard" - https://www.risein.com/blog/introduction-to-erc-1155-token-standard

[5] CoinTracker - "Introduction to the ERC-1155 Token Standard" - https://www.cointracker.io/learn/erc-1155