---
type: api
title: Start the watch service
description: Start the Watcher service if it is not already running.
url: https://www.elastic.co/elastic/docs-builder/docs/4493/api/doc/elasticsearch/operation/operation-watcher-start
resource: https://www.elastic.co/elastic/docs-builder/docs/4493/api/doc/elasticsearch/operation/operation-watcher-start
products:
  - Elasticsearch
---

# Start the watch service

## Paths

- `POST` `/_watcher/_start`

## Description

Start the Watcher service if it is not already running.

## Required authorization

- Cluster privileges: `manage_watcher`

## Authentication

- Api key: `Authorization: <value>`
  Elasticsearch APIs support key-based authentication.
  You must create an API key and use the encoded value in the request header.
  For example:
  
  
  ```
  curl -X GET "${ES_URL}/_cat/indices?v=true" \
    -H "Authorization: ApiKey ${API_KEY}"
  ```
  
  To get API keys, use the `/_security/api_key` APIs.
- Basic: `Authorization: Basic <credentials>`
- Bearer: `Authorization: Bearer <token>`
  Elasticsearch APIs support the use of bearer tokens in the `Authorization` HTTP header to authenticate with the API.
  For examples, refer to [Token-based authentication services](https://www.elastic.co/docs/deploy-manage/users-roles/cluster-or-deployment-auth/token-based-authentication-services)

## Query string parameters

- `master_timeout` (string · default: 30s) — optional
  Period to wait for a connection to the master node.

## Response

`application/json`

- `acknowledged` (boolean)
  For a successful response, this value is always true. On failure, an exception is returned instead.
## Code examples

#### Console

```console
POST _watcher/_start
```

#### JavaScript

```javascript
const response = await client.watcher.start();
```

#### Python

```python
resp = client.watcher.start()
```

#### curl

```curl
curl -X POST "$ELASTICSEARCH_URL/_watcher/_start" \
  -H "Authorization: ApiKey $ELASTIC_API_KEY"
```

#### Java

```java
client.watcher().start(s -> s);
```

#### PHP

```php
$resp = $client->watcher()->start();
```

#### Ruby

```ruby
response = client.watcher.start
```

## Response examples

#### Watcher start response example1

A successful response from `POST _watcher/_start`.

```json
{
  "acknowledged": true
}
```