***

title: Postman SDK customization options
updated: 2026-02-04T00:00:00.000Z
max-toc-depth: 2
----------------

The `customizations` section of the [`postman-sdk.config.json` file](/docs/sdk-generator/configure/overview/) is used to customize your SDKs.

## authentication

The `authentication` options allow you to configure the authentication that your API uses, that's set using the [auth](/docs/sdk-generator/configure/core-options/#auth) options.

This is an object with the following options:

| Option   | Type   | Description                                 |
| -------- | ------ | ------------------------------------------- |
| `access` | object | Custom access token authentication options. |
| `apiKey` | object | API key authentication options.             |

### access

The access options allow you to configure the custom access token that's sent to your API when the [`auth`](/docs/sdk-generator/configure/core-options/#auth) option has a custom prefix.

This is an object with the following options:

| Option   | Type   | Description                                                   |
| -------- | ------ | ------------------------------------------------------------- |
| `prefix` | string | The prefix to use for the custom access token authentication. |

#### prefix

The `prefix` is used to define a custom prefix when using an access token. By default, when using custom access token authentication, the Authorization header is passed as `Bearer <token>`.

For example, if your bearer token is `Passw0rd123!`, the header would be:

| Header          | Value                 |
| --------------- | --------------------- |
| `Authorization` | `Bearer Passw0rd123!` |

By setting the `prefix`, you can replace Bearer with the value of your choice.

For example, if you have the following:

```json
{
    ...
    "auth": [
      "custom"
    ],
    "customizations": {
      "authentication": {
        "access": {
          "prefix": "Token"
        }
      }
    }
    ...
}
```

Then, the header would be:

| Header          | Value                |
| --------------- | -------------------- |
| `Authorization` | `Token Passw0rd123!` |

### apiKey

The `apiKey` option is used to configure the API key authentication for the SDKs. This is used if the auth setting is set to `apikey`.

This is an object with the following options:

| Option   | Type   | Default     | Description                                 |
| -------- | ------ | ----------- | ------------------------------------------- |
| `header` | string | `X-API-KEY` | Custom access token authentication options. |

#### header

The `header` option sets the header to use for the API key authentication. This is used by the SDKs to set the header when making requests to the API.

For example, if you have the following:

```json
{
    ...
    "customizations": {
      "authentication": {
        "apiKey": {
          "header":"MY_CUSTOM_APIKEY_HEADER"
        }
      }
    }
    ...
}
```

Then, the API key will be passed to your API using the `MY_CUSTOM_APIKEY_HEADER` header.

If this isn't set, then API keys by default are passed using the `X-API-KEY` header.