wallet_watchAsset
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.
Params
(2)1. type (required)
Supports ERC-20, ERC-721, and ERC-1155 tokens. Support for ERC-721 and ERC-1155 tokens is experimental and currently only available on the extension (not on mobile). See MIP-1 and MIP proposal lifecycle for more information.
2. options (required)
The address of the token contract.
A ticker symbol or shorthand, up to 11 characters (optional for ERC-20 tokens).
The number of token decimals (optional for ERC-20 tokens).
A string URL of the token logo (optional for ERC-20 tokens).
The unique identifier of the NFT (required for ERC-721 and ERC-1155 tokens).
Result
(WatchAssetResult)true if the token was added, false otherwise.
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