# PATCH - Update

The Custom Audience API 1.0 only accepts custom user IDs and avertising IDs. For audiences with install IDs, the version 1.1 should be used.

The Custom Audience API enables you to create, update, delete and list custom audiences. A **custom audience** can contain a list of custom user IDs or advertising IDs (GAID or IDFA).

This is useful to target segments with push notifications or In-App messages, either they are coming from your userbase or created by third-party tools.

Custom audiences created using the API can be targeted from Batch’s dashboard or the Campaigns API.

### Request structure

#### Route

The Custom Audience API exposes a PATCH endpoint that allows to add or delete users from a custom audience :

`https://api.batch.com/1.0/BATCH_API_KEY/custom-audience/AUDIENCE_NAME`

Here is a valid cURL example:

```bash
curl -H "Content-Type: application/json" -H "X-Authorization: BATCH_REST_API_KEY" -X PATCH -d "@payload.json" "https://api.batch.com/1.0/BATCH_API_KEY/custom-audience/AUDIENCE_NAME"
```

The `AUDIENCE_NAME` value is the name of the existing audience you want this operation to be applied to.

The `BATCH_API_KEY` value is either your **Live**, **Dev** or **SDK** Batch API key from the settings page of your app within the dashboard (⚙ Settings → General).

#### Headers

In order to authenticate with the API, you need to provide your **company REST API Key** as the value of the `X-Authorization` header. You can find it in ⚙ Settings → General.

#### Patch data

The body of the request must contain a **valid JSON payload** describing the operations to be executed on the custom audience.

Here is a how a complete JSON payload looks like:

```json
{
  "type": "custom_ids",
  "ids": [
    {
      "action": "add",
      "id": "USER_CUSTOM_ID1"
    },
    {
      "action": "remove",
      "id": "USER_CUSTOM_ID2"
    }
  ]
}
```

Let's see the parameters in detail.

<table><thead><tr><th width="91">Id</th><th width="633.5">Description</th></tr></thead><tbody><tr><td><code>type</code></td><td><strong>string</strong> - <em>Required</em><br>Type of the audience.<br>Acceptable values include: <code>custom_ids</code> or <code>advertising_ids</code> .<br><em>E.g.</em><code>{"type":"custom_ids"}</code></td></tr><tr><td><code>ids</code></td><td><strong>Array of Objects</strong> - <em>Required</em><br>An array of objects describing actions to be applied to the custom audience.<br>Supports up to 10,000 elements.<br><em>E.g.</em><code>[{"action":"add","id":"USER_CUSTOM_ID1"}]</code></td></tr></tbody></table>

<table data-header-hidden><thead><tr><th width="126.5"></th><th width="454"></th></tr></thead><tbody><tr><td><code>action</code></td><td><strong>String</strong> - <em>Required</em><br>The action to be applied to the custom audience.<br>Acceptable values include: <code>add</code> or <code>remove</code> .<br><em>E.g.</em><code>{"action":"add"}</code></td></tr><tr><td><code>id</code></td><td><strong>String - Max. 128 chars</strong> -<br>The ID that will be added to or deleted from the audience.<br><em>E.g.</em><code>{"id":"USER_CUSTOM_ID"}</code></td></tr></tbody></table>

**NOTE**: If both add and remove actions are applied to the same ID, the ID will be deleted from the audience.

### Responses

#### Success

If the POST to the API endpoint is successful you will receive an **HTTP 201** confirmation and **a token**.

```json
{
  "indexing_token": "a0082dc6860938a26280bd3ba927303b"
}
```

Once you get your token, you can use it to [check the indexing state](/developer/api/mep/custom-audience/1.0/get.md) of this update with the API.

#### Failure

If the POST data does not meet the API requirements you will receive an actionable error message. Contact us at <support@batch.com> if you need further support.

* `AUTHENTICATION_INVALID` (Http status code: 401, Error code: 10)
* `API_MISUSE` (Http status code: 403, Error code: 12)
* `ROUTE_NOT_FOUND` (Http status code: 404, Error code: 20)
* `MISSING_PARAMETER` (Http status code: 400, Error code: 30)
* `MALFORMED_PARAMETER` (Http status code: 400, Error code: 31)
* `MALFORMED_JSON_BODY` (Http status code: 400, Error code: 32)
* `SERVER_ERROR` (Http status code: 500, Error code: 1)
* `MAINTENANCE_ERROR` (Http status code: 503, Error code: 2)

### Processing time

While the indexation of IDs is usually done in realtime, we offer no guarantees. If you send a campaign right after the custom audience creation, you might end up with a campaign targeting nobody.


---

# 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://doc.batch.com/developer/api/mep/custom-audience/1.0/update.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.