# Retrieve a controller by id

This endpoint retrieves a specific controller by its unique identifier (Id).

Controllers on the TEOS platform are blockchain-level entities that define restrictions and permissions for specific operations with blockchain data types.

A controller may include whitelisted and blacklisted addresses, which determine which wallets or users can interact with the associated assets.\
This endpoint returns full details of a controller, including its metadata and address lists, by providing its unique ID.

📘 Learn more about [controllers](/resources/using-the-teos-api/concepts/controllers.md).

#### Request Endpoint:

```http
GET /odata/v1.0/Controllers({key})
```

Retrieves the controller object identified by the specified {key} (UUID).\
You can optionally use OData query options to expand related entities or select specific fields.

**Supported OData query options:**\
Expand, Select

#### Parameters

| **Name** | **Type**      | **Description**                                    |
| -------- | ------------- | -------------------------------------------------- |
| key      | string (UUID) | The unique identifier of the requested controller. |

#### Example Request:

```http
GET /Controllers(6046ab4b-c4c8-4839-7f1c-08da318afc96)
```

#### Response Body:

`application/json`  — Returns the details of the requested controller.

| **Parameter**              | **Type**      | **Description**                                                    |
| -------------------------- | ------------- | ------------------------------------------------------------------ |
| Id                         | string (UUID) | Unique identifier of the controller.                               |
| Name                       | string        | Name of the controller.                                            |
| Description                | string        | Description of the controller.                                     |
| EthereumAddress/ICPAddress | string        | The blockchain address associated with the controller.             |
| IssuerAddress              | string        | Address of the issuer that created the controller.                 |
| WhitelistAddresses         | array         | List of addresses allowed to interact with this controller.        |
| WhitelistAddresses.Address | string        | Whitelisted blockchain address.                                    |
| WhitelistAddresses.Limit   | string        | Optional transaction or interaction limit for the address.         |
| BlacklistAddresses         | array         | List of addresses restricted from interacting with the controller. |
| BlacklistAddresses.Address | string        | Blacklisted blockchain address.                                    |
| BlacklistAddresses.Reason  | integer       | Reason code for blacklisting.                                      |
| CreatedInBlockchainOn      | datetime      | Date and time when the controller was created on the blockchain.   |
| CreatedBy                  | string (UUID) | Identifier of the user who created the controller.                 |
| CreatedOn                  | datetime      | Timestamp when the controller was created in the system.           |
| UpdatedOn                  | datetime      | Timestamp of the last update.                                      |
| UpdatedBy                  | string (UUID) | Identifier of the user who last updated the controller.            |

#### Example Response Body:

In EVM-compatible networks (e.g., Sparknet, Ethereum, and Polygon), the  address ("IssuerAddress", "WhetelistAddress" and etc) is 42 characters long. In non-EVM networks, the address length may differ. For example, on Internet Computer, it is 63 characters.

```json
{
  "Id": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
  "Name": "Example Controller",
  "Description": "Defines whitelist and blacklist for controlled asset operations",
  "EthereumAddress": "0xe0450ce1e2ef73b15514ae6a003b90d0ebac8836",
  "IssuerAddress": "0x1977832755fb404b96ea7a1d95b67df2135e94f1",
  "WhitelistAddresses": [
    {
      "Address": "0x3c878fccdbae5915433e0ec859c781f1d07b3665",
      "Limit": "1000"
    }
  ],
  "BlacklistAddresses": [
    {
      "Address": "0x1977832755fb404b96ea7a1d95b67df2135e94f1",
      "Reason": 1
    }
  ],
  "CreatedInBlockchainOn": "2025-10-10T07:15:44.565Z",
  "CreatedBy": "37514BE7-D096-4BB8-95DA-EDB03B723BB2",
  "CreatedOn": "2022-07-21T09:40:23.263Z",
  "UpdatedOn": "2022-07-21T09:40:23.263Z",
  "UpdatedBy": "3fa85f64-5717-4562-b3fc-2c963f66afa6"
}

```

#### Response Codes:

| **Code** | **Description**                                     |
| -------- | --------------------------------------------------- |
| 200      | The controller was successfully retrieved.          |
| 400      | The request is invalid. Error details are included. |
| 401      | Unauthorized.                                       |
| 404      | The controller does not exist.                      |

<br>


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://teos-docs.coreledger.net/guides/controllers/retrieve-a-controller-by-id.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.