> ## Documentation Index
> Fetch the complete documentation index at: https://docs.trusset.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Detect Token

> Read a contract and report which token standard it follows

Reads the contract at an address and reports what it is, without writing anything. Call it before [Import Token](/endpoints/tokenization/import-token) so a form is never filled in for a request that can only be refused.

## Body Parameters

<ParamField body="tokenAddress" type="string" required>
  Contract to read, on the network your instance resolves to. Case-insensitive, lowercased in the response.
</ParamField>

## Response Fields

<ResponseField name="data" type="object">
  <Expandable>
    <ResponseField name="tokenAddress" type="string">The address read, lowercased.</ResponseField>
    <ResponseField name="framework" type="string">`erc3643`, `erc1400`, `erc721`, `erc1155` or `erc20`. The first standard the contract answers for, tested in that order.</ResponseField>
    <ResponseField name="name" type="string">Token name. Falls back to the symbol, then to a name derived from the framework, when the contract does not answer.</ResponseField>
    <ResponseField name="symbol" type="string">Token symbol, at most 16 characters.</ResponseField>
    <ResponseField name="decimals" type="integer">Decimals, defaulting to `18` when unreadable. Always `0` for `erc721` and `erc1155`.</ResponseField>
    <ResponseField name="totalSupply" type="string">Total supply formatted at `decimals`. Always `"0"` for `erc1155`, which has no single supply.</ResponseField>
    <ResponseField name="environment" type="string">The instance type this read ran against.</ResponseField>
    <ResponseField name="degradedMetadata" type="boolean">Present and `true` when part of the metadata could not be read and a fallback was used. Absent on a clean read. Do not treat a fallback name or symbol as the token's own.</ResponseField>
    <ResponseField name="details" type="object">Framework-specific facts. See below.</ResponseField>
    <ResponseField name="alreadyImported" type="boolean">`true` when this instance already holds an active import for the address. Importing again is refused.</ResponseField>
    <ResponseField name="isOwn" type="boolean">`true` when the asset belongs to this instance already. Importing it is refused.</ResponseField>
    <ResponseField name="ownTokenKind" type="string">What kind of own asset it is, or `null`.</ResponseField>
  </Expandable>
</ResponseField>

## The details block

`details` carries only what the detected standard exposes. It is `{}` for `erc20` and `erc721`.

| `framework` | `details`                                               |
| ----------- | ------------------------------------------------------- |
| `erc3643`   | `identityRegistry`, `compliance`, `onchainID`, `paused` |
| `erc1400`   | `isControllable`, `isIssuable`, `granularity`           |
| `erc1155`   | `uri`, the collection metadata URI                      |

An address inside `details` is `null` when the contract returned nothing usable, and `paused` is `null` when the flag could not be read, which is not the same as unpaused.

A token this instance issued through Trusset comes back as `erc3643` with two extra keys: `trussetStockToken: true` and `isin`. It is reported so it can be recognized, not so it can be imported.

<Warning>
  Detection reports the standard a contract answers for, not that the contract is safe or that the asset behind it is what anyone claims. It reads public view functions and nothing more.
</Warning>

<RequestExample>
  ```bash cURL theme={null}
  curl -X POST "https://api.trusset.org/external-tokens/api/detect" \
    -H "X-API-Key: trusset_your_key_here" \
    -H "Content-Type: application/json" \
    -d '{"tokenAddress": "0x9f8c1d4b2e7a3056c1b8f4d29e0a7c3518b6d24f"}'
  ```

  ```typescript TypeScript theme={null}
  const res = await fetch(
    'https://api.trusset.org/external-tokens/api/detect',
    {
      method: 'POST',
      headers: { 'X-API-Key': 'trusset_your_key_here', 'Content-Type': 'application/json' },
      body: JSON.stringify({ tokenAddress })
    }
  );
  const { success, data, error } = await res.json();

  if (!success) throw new Error(`${error.code}: ${error.message}`);
  if (data.alreadyImported || data.isOwn) {
    throw new Error('This token cannot be imported into this instance');
  }
  ```
</RequestExample>

<ResponseExample>
  ```json Response - ERC-3643 theme={null}
  {
    "success": true,
    "data": {
      "tokenAddress": "0x9f8c1d4b2e7a3056c1b8f4d29e0a7c3518b6d24f",
      "framework": "erc3643",
      "name": "Nyala Fund I",
      "symbol": "NYF1",
      "decimals": 18,
      "totalSupply": "5000000.0",
      "environment": "PRODUCTION",
      "details": {
        "identityRegistry": "0x9e3c8A15f4d70b2681C5a3f9027d4bE8115C7d21",
        "compliance": "0x2b7Ff4E80a1c53D6970bC81dE4a5f0917Ac3d829",
        "onchainID": null,
        "paused": false
      },
      "alreadyImported": false,
      "isOwn": false,
      "ownTokenKind": null
    }
  }
  ```

  ```json Response - Plain ERC-20 theme={null}
  {
    "success": true,
    "data": {
      "tokenAddress": "0x3f8b1c7e2a9d5f4b6c8e0a2d7f1b3c9e5a4d6b8c",
      "framework": "erc20",
      "name": "Wrapped Asset",
      "symbol": "WRAP",
      "decimals": 18,
      "totalSupply": "1200000.0",
      "environment": "PRODUCTION",
      "details": {},
      "alreadyImported": false,
      "isOwn": false,
      "ownTokenKind": null
    }
  }
  ```

  ```json Error - Not a Contract theme={null}
  {
    "success": false,
    "data": null,
    "error": {
      "code": "NOT_A_CONTRACT",
      "message": "No contract found at this address on the selected network"
    }
  }
  ```
</ResponseExample>

## Error Codes

| Code                   | HTTP  | Cause                                                           |
| ---------------------- | ----- | --------------------------------------------------------------- |
| `INVALID_ADDRESS`      | `400` | `tokenAddress` is missing or not a valid address                |
| `NOT_A_CONTRACT`       | `400` | No deployed bytecode at the address on this network             |
| `UNSUPPORTED_TOKEN`    | `400` | The contract answers for none of the five standards             |
| `DETECTION_FAILED`     | `400` | The read completed but produced nothing usable                  |
| `PROVIDER_UNAVAILABLE` | `503` | The chain could not be reached. Nothing was read. Retry shortly |