# PATCH - Update

The App Data API enables you to create, update, delete and list data you associated to your application. **App Data** lets you create **tables** of key/value pairs. It is for **application** centric data as opposed to **user** centric data. You can use the data in your targeting queries and/or in a message template.

### Request structure

#### Route

The App Data API exposes a PATCH endpoint that lets you add, update or delete keys and their associated values from a **table**:

`https://api.batch.com/1.0/BATCH_API_KEY/app-data/TABLE_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/app-data/TABLE_NAME"
```

The `TABLE_NAME` value must be a string that only contains letters, numbers or the following characters: `_`, `-`.

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 App Data table.

Here is a how a complete JSON payload looks like:

```json
{
  "overwrite": true,
  "values": {
    "aKey1": "value to add",
    "aKey2": null // value to delete
  }
}
```

Let's see the parameters in detail.

\[ { "id": "overwrite", "type": "boolean", "req": "Required", "desc": "Determines whether all the table data should be overwritten" }, { "id": "values", "type": "object", "req": "Required", "desc": "A dictionary of key/value. A value must be a string or null. A `null` value will delete the associated key.\
Supports up to 10,000 elements." } ]

**NOTE**: In overwrite mode, null values are not supported.

### Responses

#### Success

If the POST to the API endpoint is successful you will receive an **HTTP 202** confirmation and an empty json payload.

#### 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 application data is usually done in realtime, **we offer no guarantees**. If you send a campaign right after the app-data creation, you might end up with missing keys.


---

# 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/app-data/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.