---
title: "loki.source.api | Grafana Agent documentation"
description: "Learn about loki.source.api"
---

> For a curated documentation index, see [llms.txt](/llms.txt). For the complete documentation index, see [llms-full.txt](/llms-full.txt).

# loki.source.api

`loki.source.api` receives log entries over HTTP and forwards them to other `loki.*` components.

The HTTP API exposed is compatible with [Loki push API](/docs/loki/latest/api/#push-log-entries-to-loki) and the `logproto` format. This means that other [`loki.write`](../loki.write/) components can be used as a client and send requests to `loki.source.api` which enables using the Agent as a proxy for logs.

## Usage

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

```alloy
loki.source.api "LABEL" {
    http {
        listen_address = "LISTEN_ADDRESS"
        listen_port = PORT
    }
    forward_to = RECEIVER_LIST
}
```

The component will start HTTP server on the configured port and address with the following endpoints:

- `/loki/api/v1/push` - accepting `POST` requests compatible with [Loki push API](/docs/loki/latest/api/#push-log-entries-to-loki), for example, from another Grafana Agent’s [`loki.write`](../loki.write/) component.
- `/loki/api/v1/raw` - accepting `POST` requests with newline-delimited log lines in body. This can be used to send NDJSON or plaintext logs. This is compatible with promtail’s push API endpoint - see [promtail’s documentation](/docs/loki/latest/clients/promtail/configuration/#loki_push_api) for more information. NOTE: when this endpoint is used, the incoming timestamps cannot be used and the `use_incoming_timestamp = true` setting will be ignored.
- `/loki/ready` - accepting `GET` requests - can be used to confirm the server is reachable and healthy.
- `/api/v1/push` - internally reroutes to `/loki/api/v1/push`
- `/api/v1/raw` - internally reroutes to `/loki/api/v1/raw`

## Arguments

`loki.source.api` supports the following arguments:

Expand table

| Name                     | Type                 | Description                                                | Default | Required |
|--------------------------|----------------------|------------------------------------------------------------|---------|----------|
| `forward_to`             | `list(LogsReceiver)` | List of receivers to send log entries to.                  |         | yes      |
| `use_incoming_timestamp` | `bool`               | Whether or not to use the timestamp received from request. | `false` | no       |
| `labels`                 | `map(string)`        | The labels to associate with each received logs record.    | `{}`    | no       |
| `relabel_rules`          | `RelabelRules`       | Relabeling rules to apply on log entries.                  | `{}`    | no       |

The `relabel_rules` field can make use of the `rules` export value from a [`loki.relabel`](../loki.relabel/) component to apply one or more relabeling rules to log entries before they’re forwarded to the list of receivers in `forward_to`.

## Blocks

The following blocks are supported inside the definition of `loki.source.api`:

Expand table

| Hierarchy | Name          | Description                                        | Required |
|-----------|---------------|----------------------------------------------------|----------|
| `http`    | [http](#http) | Configures the HTTP server that receives requests. | no       |

### http

The `http` block configures the HTTP server.

You can use the following arguments to configure the `http` block. Any omitted fields take their default values.

Expand table

| Name                   | Type       | Description                                                                                                      | Default  | Required |
|------------------------|------------|------------------------------------------------------------------------------------------------------------------|----------|----------|
| `conn_limit`           | `int`      | Maximum number of simultaneous HTTP connections. Defaults to no limit.                                           | `0`      | no       |
| `listen_address`       | `string`   | Network address on which the server listens for new connections. Defaults to accepting all incoming connections. | `""`     | no       |
| `listen_port`          | `int`      | Port number on which the server listens for new connections.                                                     | `8080`   | no       |
| `server_idle_timeout`  | `duration` | Idle timeout for HTTP server.                                                                                    | `"120s"` | no       |
| `server_read_timeout`  | `duration` | Read timeout for HTTP server.                                                                                    | `"30s"`  | no       |
| `server_write_timeout` | `duration` | Write timeout for HTTP server.                                                                                   | `"30s"`  | no       |

## Exported fields

`loki.source.api` does not export any fields.

## Component health

`loki.source.api` is only reported as unhealthy if given an invalid configuration.

## Debug metrics

The following are some of the metrics that are exposed when this component is used. Note that the metrics include labels such as `status_code` where relevant, which can be used to measure request success rates.

- `loki_source_api_request_duration_seconds` (histogram): Time (in seconds) spent serving HTTP requests.
- `loki_source_api_request_message_bytes` (histogram): Size (in bytes) of messages received in the request.
- `loki_source_api_response_message_bytes` (histogram): Size (in bytes) of messages sent in response.
- `loki_source_api_tcp_connections` (gauge): Current number of accepted TCP connections.

## Example

This example starts an HTTP server on `0.0.0.0` address and port `9999`. The server receives log entries and forwards them to a `loki.write` component while adding a `forwarded="true"` label. The `loki.write` component will send the logs to the specified loki instance using basic auth credentials provided.

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

```alloy
loki.write "local" {
    endpoint {
        url = "http://loki:3100/api/v1/push"
        basic_auth {
            username = "<your username>"
            password_file = "<your password file>"
        }
    }
}

loki.source.api "loki_push_api" {
    http {
        listen_address = "0.0.0.0"
        listen_port = 9999
    }
    forward_to = [
        loki.write.local.receiver,
    ]
    labels = {
        forwarded = "true",
    }
}
```

## Compatible components

`loki.source.api` can accept arguments from the following components:

- Components that export [Loki `LogsReceiver`](../../compatibility/#loki-logsreceiver-exporters)

> 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.