---
title: "prometheus.enrich | Grafana Cloud documentation"
description: "The prometheus.enrich component enriches metrics with labels from service discovery"
---

# `prometheus.enrich`

> **EXPERIMENTAL**: This is an [experimental](/docs/release-life-cycle/) component. Experimental components are subject to frequent breaking changes, and may be removed with no equivalent replacement. To enable and use an experimental component, you must set the `stability.level` [flag](/docs/alloy/latest/reference/cli/run/) to `experimental`.

The `prometheus.enrich` component enriches metrics with additional labels from service discovery targets. It matches a label from incoming metrics against a label from discovered targets, and copies specified labels from the matched target to the metric sample. If match doesn’t happen, the metrics will be passed through.

## Usage

Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```alloy
prometheus.enrich "<LABEL>" {
  targets = <DISCOVERY_COMPONENT>.targets
  
  target_match_label = "<LABEL>"
  
  forward_to = [<RECEIVER_LIST>]
}
```

## Arguments

You can use the following arguments with `prometheus.enrich`:

Expand table

| Name                  | Type                    | Description                                                                                        | Default | Required |
|-----------------------|-------------------------|----------------------------------------------------------------------------------------------------|---------|----------|
| `forward_to`          | `list(MetricsReceiver)` | Where the metrics should be forwarded to, after enrichment.                                        |         | yes      |
| `target_match_label`  | `string`                | The label from discovered targets to match against, for example, `"__inventory_consul_service"`.   |         | yes      |
| `targets`             | `list(map(string))`     | List of targets from a discovery component.                                                        |         | yes      |
| `labels_to_copy`      | `list(string)`          | List of labels to copy from discovered targets to metrics. If empty, all labels are copied.        |         | no       |
| `metrics_match_label` | `string`                | The label from incoming metrics to match against discovered targets, for example `"service_name"`. |         | no       |

If not provided, the `metrics_match_label` attribute defaults to the value of `target_match_label`.

## Blocks

The `prometheus.enrich` component doesn’t support any blocks. You can configure this component with arguments.

## Exports

The following values are exported:

Expand table

| Name       | Type              | Description                                               |
|------------|-------------------|-----------------------------------------------------------|
| `receiver` | `MetricsReceiver` | The input receiver where samples are sent to be enriched. |

## Debug information

`prometheus.enrich` doesn’t expose any component-specific debug information.

## Debug metrics

- `prometheus_fanout_latency` (histogram): Write latency for sending to direct and indirect components.
- `prometheus_forwarded_samples_total` (counter): Total number of samples sent to downstream components.
- `prometheus_target_cache_size` (gauge): The number of targets in the `targets` list.

## Example

### Enrich metrics from `prometheus.scrape`

The following example shows how the `prometheus.enrich` enriches incoming metrics from `prometheus.scrape.default`, using HTTP discovery, and forwards the results to `prometheus.remote_write.default` component:

Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```alloy
discovery.http "default" {
    url = "http://network-inventory.example.com/prometheus_sd"
}

prometheus.scrape "default" {
  targets = [
    {"__address__" = "example-app:9001"},
  ]

  forward_to = [prometheus.enrich.default.receiver]
}

prometheus.enrich "default" {
	targets = discovery.http.default.targets

	target_match_label = "hostname"

	forward_to = [prometheus.remote_write.default.receiver]
}

prometheus.remote_write "default" {
  endpoint {
    url = "http://mimir:9009/api/v1/push"
  }
}
```

### Enrich metrics from `prometheus.receive_http`

The following example shows how the `prometheus.enrich` enriches incoming metrics from `prometheus.receive_http.default`, using HTTP discovery, and forwards the results to `prometheus.remote_write.default` component:

Alloy ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```alloy
discovery.file "network_devices" {  
   files = ["/etc/alloy/devices.json"]  
}  
  
prometheus.receive_http "default" {
  http {
    listen_address = "0.0.0.0"
    listen_port = 9999
  }
  
  forward_to = [prometheus.enrich.default.receiver]
}

prometheus.enrich "default" {  
    targets = discovery.file.network_devices.targets  
  
    target_match_label = "hostname"  
    
    forward_to = [prometheus.remote_write.default.receiver]  
}

prometheus.remote_write "default" {  
  endpoint {  
    url = "http://mimir:9009/api/v1/push"    
  }    
}
```

## Compatible components

`prometheus.enrich` can accept arguments from the following components:

- Components that export [Targets](/docs/grafana-cloud/send-data/alloy/reference/compatibility/#targets-exporters)
- Components that export [Prometheus `MetricsReceiver`](/docs/grafana-cloud/send-data/alloy/reference/compatibility/#prometheus-metricsreceiver-exporters)

`prometheus.enrich` has exports that can be consumed by the following components:

- Components that consume [Prometheus `MetricsReceiver`](/docs/grafana-cloud/send-data/alloy/reference/compatibility/#prometheus-metricsreceiver-consumers)

> Note
> 
> Connecting some components may not be sensible or components may require further configuration to make the connection work correctly. Refer to the linked documentation for more details.