Semi-Fungible Tokens (SFT)

Semi-Fungible Tokens (SFTs) represent blockchain's most versatile asset class—combining the interchangeability of cryptocurrencies with the uniqueness of NFTs in a single, efficient standard. For Klever Blockchain builders and users, SFTs open doors that neither fungible tokens nor NFTs can unlock alone: concert tickets that transform into collectibles, gaming currencies that coexist with unique weapons, and fractional ownership of real-world assets—all managed from one smart contract with dramatically lower costs.

What are Semi-Fungible Tokens?

Semi-Fungible Tokens combine both fungible and non-fungible behaviors within a single collection. Tokens sharing the same nonce (ID) are fungible with each other, while different nonces represent distinct, non-fungible asset types.

The classic example: concert tickets. Before the show, all General Admission tickets (same nonce) are interchangeable—you can swap yours for any other GA ticket. After the event, applications can interpret the ticket differently based on metadata (e.g., marking it as "redeemed"), turning it into a collectible. The token itself doesn't change type—its metadata and how applications interpret it does.

Key Characteristics

The core SFT principle: tokens that share an ID are fungible within that class, while different IDs represent distinct assets. This enables sophisticated systems using a single contract.

• Fungible within nonce - All tokens with the same nonce/ID are interchangeable
• Non-fungible across nonces - Different nonces represent distinct asset types
• Configurable supply - Set supply per nonce (1 for unique, many for editions)
• Single collection efficiency - One collection manages unlimited token types
• Metadata-driven state - Application logic interprets token state via attributes

State Transition Triggers

State transitions in SFTs are handled through application logic rather than token-level changes. Common triggers include:

• Time-based: Event passes expire, becoming historical artifacts
• Redemption-based: Vouchers are used, becoming proof-of-purchase NFTs
• Action-based: Gaming items gain unique attributes through player actions
• Attribute acquisition: Standard items become unique when signed or modified

Klever Blockchain's Native SFT Advantage

Klever Blockchain takes SFT implementation further than Ethereum-based solutions by building SFT support directly into the protocol. Rather than requiring developers to deploy complex smart contracts, Klever's KDA (Klever Digital Assets) framework offers native token creation with SFT capabilities out of the box.

The KDA framework supports three token types:

• Fungible — Traditional interchangeable tokens (balance-based)
• NonFungible — Unique one-of-one assets (each nonce has supply of 1)
• SemiFungible — Multiple nonces with configurable supply per nonce

No Smart Contract Required

Creating SFTs on Klever requires no smart contract expertise. The 3-step process through Klever Wallet or KleverScan handles everything: define token properties, configure permissions, and deploy. For developers wanting deeper control, the Rust-based KVM (Klever Virtual Machine) provides full programmability.

On-Chain Metadata Storage

Klever stores comprehensive token data directly on-chain:

KdaTokenData {
    token_type: SemiFungible,
    amount: BigUint,           // Current balance
    name: ManagedBuffer,       // Display name
    attributes: ManagedBuffer, // Custom user-defined data
    royalties: BigUint,        // Built-in creator royalties
    creator: ManagedAddress,   // Immutable creator record
    uris: ManagedVec,          // Links to media
}

This hybrid approach—critical data on-chain, media off-chain—ensures token integrity while maintaining efficiency. The attributes field accepts any serializable struct, giving developers complete flexibility over what data lives permanently on Klever's ledger.

Built-in Royalties

Where Ethereum marketplaces must voluntarily honor royalty requests (and increasingly don't), Klever enforces royalties at the protocol level with 0-100% precision (stored as integers: 5566 = 55.66%).

Performance Comparison

Creating SFTs on Klever Blockchain

To create an SFT collection, use the Create Asset contract. Cost: 20,000 KLV (configurable by governance).

Define token properties, set permissions (canBurn, canMint, canFreeze, canPause, canWipe), configure royalties, and deploy.

Managing SFTs

SFTs can be managed using the Asset Trigger contract for operations such as:

• Minting new tokens within the collection
• Updating metadata
• Managing roles and permissions

For more details on available triggers, see the Contracts page.

Next Steps

• Token Comparison - Understand the differences between FT, NFT, and SFT
• Use Cases - Explore 20+ practical applications for SFTs
• Application Guide - Learn how to build applications with SFTs