# Preview metric reduction rules

URL: https://docs.hanzo.ai/docs/openapi/o11y/previewmetricreductionrule

> Estimates the series reduction and the dashboards and alerts a candidate volume-control rule would touch, without persisting it.

`POST /v1/o11y/metric_reduction_rules/preview`

> [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/metric_reduction_rules/preview` |
| **Method**    | `POST`                                                        |
| **Operation** | `PreviewMetricReductionRule`                                  |
| **Auth**      | `Authorization: Bearer $HANZO_API_KEY`                        |

Estimates the series reduction and the dashboards and
alerts a candidate volume-control rule would touch, without persisting it.

## Request

4 fields, body `application/json` (required).

| Field        | In   | Type            | Required | Description                                           |
| ------------ | ---- | --------------- | -------- | ----------------------------------------------------- |
| `labels`     | body | string\[]       | yes      | Labels are the label names the rule would match.      |
| `lookbackMs` | body | integer (int64) | —        | LookbackMs is how far back to sample when estimating. |
| `matchType`  | body | string          | yes      | MatchType is drop or keep.                            |
| `metricName` | body | string          | yes      | MetricName is the metric the rule would govern.       |

## Response

| Status    | Body                             | Meaning           |
| --------- | -------------------------------- | ----------------- |
| `200`     | o11y.O11yReductionRulePreviewOut | ok                |
| `202`     | Approval                         | held for approval |
| `default` | problem-details                  | refused           |

`200` body — 16 fields.

| Field                                  | In   | Type                          | Always | Description                                                         |
| -------------------------------------- | ---- | ----------------------------- | ------ | ------------------------------------------------------------------- |
| `data`                                 | body | o11y.O11yReductionRulePreview | —      |                                                                     |
| `data.affectedAssets`                  | body | o11y.O11yAffectedAsset\[]     | —      | AffectedAssets are the dashboards and alerts the rule would touch.  |
| `data.affectedAssets[].id`             | body | string                        | —      | ID is the asset's id.                                               |
| `data.affectedAssets[].impactedLabels` | body | string\[]                     | —      | ImpactedLabels are the rule labels the asset uses.                  |
| `data.affectedAssets[].name`           | body | string                        | —      | Name is the asset's name.                                           |
| `data.affectedAssets[].type`           | body | string                        | —      | Type is dashboard or alert\_rule.                                   |
| `data.affectedAssets[].widget`         | body | o11y.O11yAffectedWidget       | —      |                                                                     |
| `data.affectedAssets[].widget.id`      | body | string                        | —      | ID is the panel's id.                                               |
| `data.affectedAssets[].widget.name`    | body | string                        | —      | Name is the panel's name.                                           |
| `data.currentRetainedSeries`           | body | integer (uint64)              | —      | CurrentRetainedSeries is how many survive the rules in force today. |
| `data.droppedLabels`                   | body | string\[]                     | —      | DroppedLabels are the labels the rule would drop.                   |
| `data.effectiveFrom`                   | body | string (date-time)            | —      | EffectiveFrom is when the rule would take effect.                   |
| `data.ingestedSeries`                  | body | integer (uint64)              | —      | IngestedSeries is how many series the metric ingests today.         |
| `data.reductionPercent`                | body | number (double)               | —      | ReductionPercent is the estimated reduction, in percent.            |
| `data.retainedSeries`                  | body | integer (uint64)              | —      | RetainedSeries is how many would survive with the candidate rule.   |
| `status`                               | body | string                        | —      | Status is "success".                                                |

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

## Examples

**CLI**

```bash
hanzo o11y metric_reduction_rules preview \
  --labels '["<labels>"]' \
  --match-type <matchType> \
  --metric-name <metricName>
```

**SDK**

**.ts**

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

const api = new O11yApi(new Configuration({ accessToken: process.env.HANZO_API_KEY }));
const { data } = await api.previewMetricReductionRule({ metricName: "<metricName>", matchType: "<matchType>", labels: ["<labels>"] });
```

**.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).preview_metric_reduction_rule(metric_name="<metricName>", match_type="<matchType>", labels=["<labels>"])
```

**.go**

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

resp, _, err := client.O11yAPI.PreviewMetricReductionRule(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::preview_metric_reduction_rule(&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).previewMetricReductionRule();
```

**HTTP**

```bash
curl -X POST https://api.hanzo.ai/v1/o11y/metric_reduction_rules/preview \
  -H "Authorization: Bearer $HANZO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
       "metricName": "<metricName>",
       "matchType": "<matchType>",
       "labels": [
         "<labels>"
       ]
     }'
```

**MCP**

Tool `o11y`, op `PreviewMetricReductionRule` — POST the JSON-RPC envelope to `https://api.hanzo.ai/v1/mcp`.

```bash
curl -X POST https://api.hanzo.ai/v1/mcp \
  -H "Authorization: Bearer $HANZO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
       "jsonrpc": "2.0",
       "id": 1,
       "method": "tools/call",
       "params": {
         "name": "o11y",
         "arguments": {
           "op": "PreviewMetricReductionRule",
           "input": {
             "metricName": "<metricName>",
             "matchType": "<matchType>",
             "labels": [
               "<labels>"
             ]
           }
         }
       }
     }'
```

---

[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)