wallet_watchAsset

MetaMask

Requests that the user track the specified token in MetaMask. Returns a boolean indicating if the token was successfully added. Once added, the token is indistinguishable from those added using legacy methods, such as a centralized registry. Introduced by EIP-747. Currently support for ERC721 and ERC1155 tokens is limited to the extension (not on mobile) and is considered experimental. See MIP-1 and MIP proposal lifecycle for more information.

Params

(2)

1. type (required)

string

Supports ERC-20, ERC-721, and ERC-1155 tokens. Currently support for ERC721 and ERC1155 tokens is limited to the extension (not on mobile) and is considered experimental. See MIP-1 and MIP proposal lifecycle for more information.

Allowed values:

ERC20ERC721ERC1155

2. options (required)

address

string

required

The address of the token contract.

symbol

string

A ticker symbol or shorthand, up to 11 characters (optional for ERC-20 tokens).

>= 2 characters<= 11 characters

decimals

number

The number of token decimals (optional for ERC-20 tokens).

image

string

A string URL of the token logo (optional for ERC-20 tokens).

tokenId

string

The unique identifier of the NFT (required for ERC-721 and ERC-1155 tokens).

Result

(WatchAssetResult)

true if the token was added, false otherwise.

boolean

Errors

Code	Message
-32602	Must specify address, symbol, and decimals.
-32602	Invalid symbol: not a string.
-32602	Invalid symbol '${symbol}': longer than 11 characters.
-32602	Invalid decimals '${decimals}': must be 0 <= 36.
-32602	Invalid address '${address}'.
-32602	Asset type is required
-32602	Both address and tokenId are required
-32602	Invalid address
-32000	Suggested NFT is not owned by the selected account.
-32000	Suggested NFT of type ${standard} does not match received type ${type}
-32002	Unable to verify ownership. Possibly because the standard is not supported or the user's currently selected network does not match the chain of the asset in question.

Examples

Request

await window.ethereum.request({
  "method": "wallet_watchAsset",
  "params": {
    "type": "ERC20",
    "options": {
      "address": "0xb60e8dd61c5d32be8058bb8eb970870f07233155",
      "symbol": "FOO",
      "decimals": 18,
      "image": "https://foo.io/token-image.svg"
    }
  }
});

Result

true

Install MetaMask for your platform and refresh the page. The interactive features in this documentation require installing MetaMask.

Params

type

options

Request

await window.ethereum.request({
  "method": "wallet_watchAsset",
  "params": {}
});