> ## Documentation Index
> Fetch the complete documentation index at: https://seilabs-docs-evm-cookbook.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Token Standards

> Explore the different token types on Sei including native SEI, smart contract tokens (ERC20/CW20), and NFTs, with implementation guidance for each standard.

<Info>
  **Use ERC20, ERC721, or ERC1155 for new tokens.** Per [Proposal 115](https://seistream.app/proposals/115), CosmWasm code uploads and contract instantiations are disabled on Sei. As a result, no new CW20, CW721, or CW1155 tokens can be deployed. The CW standards below are documented for users and developers who interact with already-deployed legacy contracts.
</Info>

<Warning>
  **Do not use tokenfactory for new tokens or integrations.** Tokenfactory tutorials and development support have been retired. Legacy module surfaces may remain available for compatibility, but tokenfactory is not a supported development path. Use ERC20 for new fungible tokens. See [Tokenfactory is not supported](/cosmos-sdk#tokenfactory-is-not-supported).
</Warning>

This section describes the token standards that Sei supports. As a developer,
you need to understand these standards, because they are the foundation of many
dApps.

Sei supports these token types:

* [Sei token](#sei-token)
* [Smart contract tokens](#smart-contract-tokens)

## Sei token

The Sei token is the native token of Sei. It has multiple roles in the
ecosystem:

* **Fee token**: Used to pay transaction fees on the Sei network.
* **Governance token**: Used to participate in governance decisions that affect
  the network.

**EVM**

`1 sei = 10**18 wei = 1_000_000_000_000_000_000 wei`

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

**Cosmos**

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

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

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

`1 gwei = 1 nsei`

## Fungible tokens

Fungible tokens are digital assets that are interchangeable with one another and
are not unique. Sei supports both the ERC20 and CW20 fungible token standards.

### Smart contract tokens

* **ERC20** (recommended): The ERC20 standard defines a common set of rules for
  fungible tokens on EVM-based blockchains. These tokens can be transferred,
  approved, and queried with standard functions. **Use ERC20 for any new
  fungible token on Sei.**
* **CW20** (legacy only): The Cosmos-side fungible token standard. Per
  [Prop 115](https://seistream.app/proposals/115), no new CW20 contracts
  can be deployed. Existing CW20 tokens continue to work, and you can still
  create pointer contracts for them.
* **Interoperability and pointer contracts**:
  [Pointer contracts](/learn/pointers) expose existing CW20 tokens as ERC20 on
  the EVM. A registry tracks pointer contracts and helps you discover them.

<Info>
  **Interoperability:** You can deploy ERC20 pointer contracts for existing CW20 tokens. New tokens should be deployed as ERC20 directly.

  For more detailed guidance, see the
  [pointer contracts documentation](/learn/pointers).
</Info>

## NFTs

Non-fungible tokens (NFTs) represent unique digital assets. For new NFT
collections, Sei supports ERC721 and ERC1155, and their royalty-aware
counterparts through ERC2981. Sei also supports legacy CW721 and CW1155
contracts.

* **ERC721 and ERC1155** (recommended): EVM standards for non-fungible and
  semi-fungible tokens. **Use these for any new NFT collection on Sei.**
* **ERC2981**: Defines a royalty mechanism for NFTs so that creators receive
  a percentage of sales.
* **CW721 and CW1155** (legacy only): Per [Prop 115](https://seistream.app/proposals/115),
  no new CW721 or CW1155 contracts can be deployed. Existing collections continue
  to work, and you can expose them on the EVM through pointer contracts.
* **Interoperability**: As with fungible tokens, legacy CW NFT collections
  can interact with the EVM through pointer contracts.

## Wrapped Sei (wSei)

To interact with some dApps, you may need to wrap your Sei tokens first (similar to Wrapped ETH on Ethereum). The Wrapped Sei Token (WSEI) is deployed at the contract address [`0xE30feDd158A2e3b13e9badaeABaFc5516e95e8C7`](https://seiscan.io/address/0xE30feDd158A2e3b13e9badaeABaFc5516e95e8C7).


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