# 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](https://eips.ethereum.org/EIPS/eip-747).

<SimplifiedApiReference
  method="wallet_watchAsset"
  description="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](https://eips.ethereum.org/EIPS/eip-747)."
  parameters={[
    {
      name: 'type',
      type: 'string',
      required: true,
      description:
        'The token type (`ERC20`, `ERC721`, or `ERC1155`). Support for ERC-721 and ERC-1155 tokens is experimental and currently only available on the extension (not on mobile). See [MIP-1](https://github.com/MetaMask/metamask-improvement-proposals/blob/main/MIPs/mip-1.md) and the [MIP proposal lifecycle](https://github.com/MetaMask/metamask-improvement-proposals/blob/main/PROCESS-GUIDE.md#proposal-lifecycle) for more information.',
    },
    {
      name: 'options',
      type: 'object',
      required: false,
      description: 'An object containing information about the token.',
      children: [
        {
          name: 'address',
          type: 'string',
          required: true,
          description: 'The address of the token contract.',
        },
        {
          name: 'decimals',
          type: 'number',
          required: false,
          description: 'The number of token decimals (optional for ERC-20 tokens).',
        },
        {
          name: 'image',
          type: 'string',
          required: false,
          description: 'A string URL of the token logo (optional for ERC-20 tokens).',
        },
        {
          name: 'symbol',
          type: 'string',
          required: false,
          description:
            'A ticker symbol or shorthand, up to 11 characters (optional for ERC-20 tokens).',
        },
        {
          name: 'tokenId',
          type: 'string',
          required: false,
          description:
            'The unique identifier of the NFT (required for ERC-721 and ERC-1155 tokens).',
        },
      ],
    },
  ]}
  returns={{
    type: 'boolean',
    description: '`true` if the token was added, `false` otherwise.',
  }}
  errors={[
    {
      code: -32602,
      message: 'Must specify address, symbol, and decimals.',
      description: 'Must specify address, symbol, and decimals.',
    },
    {
      code: -32602,
      message: 'Invalid symbol: not a string.',
      description: 'Invalid symbol: not a string.',
    },
    {
      code: -32602,
      message: "Invalid symbol '${symbol}': longer than 11 characters.",
      description: "Invalid symbol '${symbol}': longer than 11 characters.",
    },
    {
      code: -32602,
      message: "Invalid decimals '${decimals}': must be 0 <= 36.",
      description: "Invalid decimals '${decimals}': must be 0 <= 36.",
    },
    {
      code: -32602,
      message: "Invalid address '${address}'.",
      description: "Invalid address '${address}'.",
    },
    { code: -32602, message: 'Asset type is required.', description: 'Asset type is required.' },
    {
      code: -32602,
      message: 'Both address and tokenId are required.',
      description: 'Both address and tokenId are required.',
    },
    { code: -32602, message: 'Invalid address.', description: 'Invalid address.' },
    {
      code: -32000,
      message: 'Suggested NFT is not owned by the selected account.',
      description: 'Suggested NFT is not owned by the selected account.',
    },
    {
      code: -32000,
      message: 'Suggested NFT of type ${standard} does not match received type ${type}.',
      description: 'Suggested NFT of type ${standard} does not match received type ${type}.',
    },
    {
      code: -32002,
      message:
        "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.",
      description:
        "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.",
    },
  ]}
  exampleRequest={`await provider.request({
    method: 'wallet_watchAsset',
    params: [
      'ERC20',
      {
        address: '0xb60e8dd61c5d32be8058bb8eb970870f07233155',
        symbol: 'FOO',
        decimals: 18,
        image: 'https://foo.io/token-image.svg',
      },
    ],
})`}
  exampleResponse={`{
    "id": 1,
    "jsonrpc": "2.0",
    "result": true
}`}
/>