Token Standards

In this section, we delve into the various token standards supported on Sei. Understanding these standards is crucial for developers as they form the foundation of many decentralized applications.

Sei offers support for four main token types:

• Sei Token
• Token Factory Tokens
• Smart Contract Tokens
• IBC Tokens

Sei Token

The Sei token is the native token of the Sei blockchain, serving multiple roles within the ecosystem.

• Fee Token: Used to pay transaction fees on the Sei network.
• Governance Token: Used to participate in governance decisions affecting the network.

EVM

1sei = 10**18 wei = 1000000000000000000wei

1sei = 10**9 wei = 1000000000gwei (giga-wei)

Native

1sei = 10**18 asei = 1000000000000000000asei (atto-sei)

1sei = 10**9 nsei = 1000000000nsei (nano-sei)

1sei = 10**6 usei = 1000000usei (micro-sei)

1gwei = 1nsei

Fungible Tokens

Fungible tokens are digital assets that are interchangeable with one another and are not unique. Sei supports both ERC20 and CW20 fungible token standards, so developers have the option to create tokens using the native TokenFactory or via smart contract standards.

TokenFactory

TokenFactory allows for the creation of tokens that are natively integrated into the base chain modules. This integration means bank balances are available through native bank queries, unlike CW20 or ERC20 tokens which require querying the smart contract directly.

• Native Integration: Tokens created via TokenFactory are integrated into the chain allowing the core modules to efficiently interact with these tokens and RPC clients to return their balances in native bank and account queries.
• Efficient Queries: Tokens are available through native queries, making it more efficient than querying smart contracts directly.
• Recommended Use: Ideal for scenarios where performance and ease of access are priorities or for native applications.

Learn more about creating tokens using TokenFactory in the TokenFactory Tutorial.

Smart Contract Tokens

• ERC20: The ERC20 standard defines a common set of rules for fungible tokens on EVM-based blockchains. These tokens can be transferred, approved, and queried using standard functions.
• CW20: The CW20 standard is the wasm equivalent of ERC20, providing similar functionalities with much easier tracking and no need for external indexers.
• Standard Compatibility: Supporting both CW20 and ERC20 ensure compatibility with existing dApps and ecosystems while enabling onboarding of EVM-centric projects.
• Interoperability: Both standards support pointer contracts, enabling seamless interaction between native and EVM environments.
• Interoperability and Pointer Contracts: Pointer contracts enable interoperability between ERC20 and CW20 tokens, allowing for seamless interaction between the two standards. A registry is kept to track pointer contracts and facilitate interoperability.
• Recommended Use: Suitable for applications needing standard token interactions for use with existing dApps and maximum compatibility.

Interoperability

Regardless of the choice, both TokenFactory and CW20/ERC20 tokens can have pointer contracts deployed, facilitating seamless cross-vm interoperability.

For more detailed guidance, refer to the Pointer Contracts Documentation.

NFTs

Non-fungible tokens (NFTs) represent unique digital assets. Sei supports both ERC721 and CW721 standards as well as their counterparts with royalties (2981).

• ERC721: The ERC721 standard defines the structure for non-fungible tokens on EVM-based blockchains. Each token is unique and cannot be exchanged on a one-to-one basis like fungible tokens.
• CW721: The CW721 standard is the wasm equivalent of ERC721, providing similar functionalities with the added benefit of not requiring complicated indexing techniques and platforms to track them.
• CW2981 & ERC2981: These standards define royalty mechanisms for NFTs, ensuring creators receive a percentage of sales.
• Interoperability: Similar to fungible tokens, NFTs can interact across different standards using pointer contracts.
• Pointer Contract Registry: A registry for tracking pointer contracts specific to NFTs.

IBC Tokens

Inter-Blockchain Communication (IBC) is a trustless permissionless interchain messaging protocol that enables communication between many different chains. IBC tokens are tokens bridged from one chain to another using the IBC protocol. Channels are set up to establish communication between the chains. Each channel has a unique identifier and specific configurations. View the IBC Channel (opens in a new tab) section of the Sei chain registry for channel information.