> ## 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.

# Tokenization

> Import a tokenized asset issued elsewhere and describe it for your instance

Importing is how an asset that already exists on chain becomes usable inside your instance. Trusset does not deploy it, does not hold it, and does not become a party to it. What the import creates is a record: what the token is, which standard it follows, what your instance calls it, and what you publish about it.

That record is what the rest of the platform reads. A [Lending](/endpoints/lending/introduction) market can only be deployed against a token this instance has imported, and the trading venues resolve their instruments the same way.

## Base Path

```
https://api.trusset.org/external-tokens/api
```

Every request authenticates with an instance API key in the `X-API-Key` header. See [Authentication](/endpoints/authentication). An import belongs to the instance that made it, so two instances importing the same contract each hold their own record.

## What can be imported

Detection reads the contract and decides which standard it follows. Five are recognized.

| `framework` | Recognized by                                        | Carried in `details`                                    |
| ----------- | ---------------------------------------------------- | ------------------------------------------------------- |
| `erc3643`   | A readable `identityRegistry()`                      | `identityRegistry`, `compliance`, `onchainID`, `paused` |
| `erc1400`   | `isControllable()` and `isIssuable()` both answering | `isControllable`, `isIssuable`, `granularity`           |
| `erc721`    | ERC-165 reporting the ERC-721 interface              | Nothing                                                 |
| `erc1155`   | ERC-165 reporting the ERC-1155 interface             | `uri`                                                   |
| `erc20`     | Name, symbol, decimals and total supply all readable | Nothing                                                 |

Detection stops at the first match, in that order. A contract that answers none of them is refused with `UNSUPPORTED_TOKEN`.

<Note>
  A token this instance issued through Trusset is detected as `erc3643` and carries `details.trussetStockToken: true` with its `isin`. It cannot be imported: it already belongs to the instance and is listed in its own assets. [Import Token](/endpoints/tokenization/import-token) refuses it with `TOKEN_IS_OWN`.
</Note>

## Import a token

<Steps>
  <Step title="Detect">
    [Detect Token](/endpoints/tokenization/detect-token) reads the contract and returns what it is, before anything is written. It also answers `alreadyImported` and `isOwn`, so a form is never filled in for a request that can only be refused.
  </Step>

  <Step title="Import">
    [Import Token](/endpoints/tokenization/import-token) writes the record. You supply the `assetType`, which is your classification of the asset and is not read from the chain.
  </Step>

  <Step title="Describe">
    [Update Profile](/endpoints/tokenization/update-profile) publishes what you assert about the instrument: issuer, jurisdiction, ISIN, LEI, documents. Everything here is your assertion, not a Trusset verification.
  </Step>

  <Step title="Keep it current">
    [Refresh On-Chain State](/endpoints/tokenization/refresh-onchain) re-reads the contract and reports whether the stored framework still matches what the chain says.
  </Step>
</Steps>

## Chain-read facts and issuer assertions stay apart

The record holds two kinds of thing and never merges them.

`name`, `symbol`, `decimals`, `framework`, `totalSupply` and `metadata` come from the contract. They are re-read by [Refresh On-Chain State](/endpoints/tokenization/refresh-onchain) and by nothing else.

`assetType`, `imageURI` and everything under `profile` are yours. No endpoint verifies them, and anywhere they surface downstream they are marked as issuer-asserted. The [instrument record](/endpoints/lending/list-pending-markets) that a lending market publishes carries that provenance explicitly.

## Response envelope

```json theme={null}
{
  "success": true,
  "data": { },
  "error": null,
  "metadata": {
    "timestamp": "2026-09-05T12:00:00.000Z",
    "requestId": "550e8400-e29b-41d4-a716-446655440000",
    "instanceId": "inst_abc123"
  }
}
```

On failure, `success` is `false`, `data` is `null`, and `error` carries `code` and `message`. Always branch on `success` rather than on the HTTP status alone.

<Warning>
  `IMPORT_NOT_FOUND` answers with `400`, not `404`. Branch on the code.
</Warning>

## Limits

An instance holds at most 200 active imports. The 201st is refused with `IMPORT_LIMIT_REACHED`. Removing an import frees a slot.

Writes on this surface are limited to 10 requests per minute, keyed by API key. [List Imports](/endpoints/tokenization/list-imports) and [Get Import](/endpoints/tokenization/get-import) are limited to 100 per minute. Both sit inside the ceiling of 200 per minute that applies to every request made with an instance API key. See [Rate Limits](/endpoints/rate-limits).