# List heartbeat

URL: https://docs.hanzo.ai/docs/openapi/o11y/get-o11y-alerts-heartbeat

> Reports whether the alert path's heartbeat is still arriving: the dead-man's switch for paging.

`GET /v1/o11y/alerts/heartbeat`

> [O11y →](https://docs.hanzo.ai/docs/openapi/o11y) · [All API references →](https://docs.hanzo.ai/docs/openapi) · [Get started →](https://docs.hanzo.ai/docs/guides)

|               |                                                 |
| ------------- | ----------------------------------------------- |
| **Address**   | `https://api.hanzo.ai/v1/o11y/alerts/heartbeat` |
| **Method**    | `GET`                                           |
| **Operation** | `get_o11y_alerts_heartbeat`                     |
| **Auth**      | `Authorization: Bearer $HANZO_API_KEY`          |

Reports whether the alert path's heartbeat is still arriving:
the dead-man's switch for paging. The o11y ruler fires one alert forever,
labelled watchdog="true", and every notification of it that reaches this
process is a heartbeat — recorded as ALERT-HEARTBEAT, never sent to a human.

It answers 200 with the heartbeat's age while one arrived within the last 15
minutes, and 503 once none has. A 503 means the path from the ruler to this
receiver stopped — the ruler, its Alertmanager, or this process — which nothing
inside the cluster can be trusted to say, so something OUTSIDE it polls this and
pages on the 503. Process-local, like the replay ring: a restart starts the
clock again rather than answering 503 before the first beat can arrive.

## Request

`GET /v1/o11y/alerts/heartbeat` takes no parameters and no body — the credential is the whole request.

## Response

| Status    | Body            | Meaning           |
| --------- | --------------- | ----------------- |
| `200`     | o11y.Heartbeat  | ok                |
| `202`     | Approval        | held for approval |
| `default` | problem-details | refused           |

`200` body — 2 fields.

| Field          | In   | Type            | Always | Description                                                                                        |
| -------------- | ---- | --------------- | ------ | -------------------------------------------------------------------------------------------------- |
| `ageSeconds`   | body | integer (int64) | —      | AgeSeconds is how long ago the last heartbeat arrived — or this process started, before its first. |
| `limitSeconds` | body | integer (int64) | —      | LimitSeconds is how old the heartbeat may get before this answers 503.                             |

Failure carries the platform error shape — see [Errors](https://docs.hanzo.ai/docs/errors).

## Examples

**CLI**

`hanzo` has no subcommand for this operation — the CLI serves only what cloud's live route table confirms. Use HTTP or an SDK.

**SDK**

**.ts**

```ts
import { Configuration, O11yApi } from 'hanzoai';

const api = new O11yApi(new Configuration({ accessToken: process.env.HANZO_API_KEY }));
const { data } = await api.getO11yAlertsHeartbeat();
```

**.py**

```python
from hanzoai.cloud import ApiClient, Configuration
from hanzoai.cloud.api import O11yApi

client = ApiClient(Configuration(access_token=os.environ["HANZO_API_KEY"]))
result = O11yApi(client).get_o11y_alerts_heartbeat()
```

**.go**

```go
cfg := hanzoai.NewConfiguration()
cfg.AddDefaultHeader("Authorization", "Bearer "+os.Getenv("HANZO_API_KEY"))
client := hanzoai.NewAPIClient(cfg)

resp, _, err := client.O11yAPI.GetO11yAlertsHeartbeat(context.Background()).Execute()
if err != nil {
	return err
}
```

**.rs**

```rust
use hanzo_client::apis::{configuration::Configuration, o11y_api};

let mut cfg = Configuration::new();
cfg.bearer_access_token = std::env::var("HANZO_API_KEY").ok();

let result = o11y_api::get_o11y_alerts_heartbeat(&cfg, Default::default()).await?;
```

**.java**

```java
import ai.hanzo.cloud.ApiClient;
import ai.hanzo.cloud.api.O11yApi;

ApiClient client = new ApiClient();
client.setBearerToken(System.getenv("HANZO_API_KEY"));

var result = new O11yApi(client).getO11yAlertsHeartbeat();
```

**HTTP**

```bash
curl https://api.hanzo.ai/v1/o11y/alerts/heartbeat \
  -H "Authorization: Bearer $HANZO_API_KEY"
```

**MCP**

MCP reaches **o11y** through the `o11y` tool, which names its 307 operations with its own verbs — this one among them, under a name only MCP declares. `describe` explains any of them:

```bash
curl -X POST https://api.hanzo.ai/v1/mcp \
  -H "Content-Type: application/json" \
  -d '{
       "jsonrpc": "2.0",
       "id": 1,
       "method": "tools/call",
       "params": {
         "name": "describe",
         "arguments": {
           "op": "list_o11y_autocomplete_aggregate_attributes"
         }
       }
     }'
```

---

[O11y API](https://docs.hanzo.ai/docs/openapi/o11y) · [All Hanzo APIs](https://docs.hanzo.ai/docs/openapi) · [Interactive reference](https://docs.hanzo.ai/docs/openapi/reference)