> ## Documentation Index
> Fetch the complete documentation index at: https://launchdarkly.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Mezmo

<View title="Developer" />

<View title="Federal docs" />

<View title="EU docs">
  <Danger>
    **This integration is not available on LaunchDarkly's European Union (EU) instance**

    To learn more, read <a href="/docs/home/infrastructure/eu">LaunchDarkly in the European Union (EU)</a>.
  </Danger>
</View>

<Note>
  **The Mezmo integration is available to customers on select plans**

  The Mezmo integration is only available to customers on select plans. To learn more, [read about our pricing](https://launchdarkly.com/pricing/). To upgrade your plan, [contact Sales](https://launchdarkly.com/contact-sales/).
</Note>

This topic explains how to use the LaunchDarkly Mezmo integration. [Mezmo](https://www.mezmo.com/) is a log management and analysis tool. Mezmo can provide insights into a service's activity. It aggregates application logs, system logs, and more into a common platform so engineers can view all of their services' activity in a single place.

The LaunchDarkly Mezmo integration sends and aggregates LaunchDarkly change history events in Mezmo.

With LaunchDarkly activity logs grouped in among your Mezmo service logs, you can more easily correlate feature flag rollouts with changes in logged behavior.

## Prerequisites

To configure the Mezmo integration, you must have a **Mezmo ingestion key**. Generate an integration key from your [Mezmo organization](https://app.mezmo.com/account/signin).

## Configure the integration

Here's how to configure the Mezmo integration:

1. Click the **gear** icon in the left sidebar to view Organization settings.
2. Click **Integrations** and find "Mezmo."
3. Click **Add integration**. The "Create Mezmo configuration" panel appears.
4. (Optional) Enter a human-readable **Name**.
5. Paste in your Mezmo **ingestion key**.
6. Specify the **Log level** with which LaunchDarkly messages should be posted. The default value is `INFO`.
7. (Optional) Configure a custom policy to control which information LaunchDarkly sends to Mezmo. To learn more, read [Advanced configuration](#advanced-configuration).
8. Click **Save configuration**.

When you configure the integration correctly, LaunchDarkly sends change data to Mezmo.

By default, this data is limited to *flag* activity only. You can expand it to other kinds of data, such as project and environment changes.

## Advanced configuration

The "Policy" configuration field lets you control which kinds of events LaunchDarkly sends to Mezmo.

The default policy value restricts it to flag changes in production environments:

<CodeGroup>
  ```txt title="Policy example" lines wrap theme={null}
  proj/*:env/production:flag/*
  ```
</CodeGroup>

You can override the default policy to restrict exported events to:

* a specific combination of LaunchDarkly projects/environments
* a specific action (or set of actions)
* a specific kind (or kinds) of entities

For example, the example policy below restricts the integration so LaunchDarkly only sends changes from the `web-app` project's production environment to Mezmo:

<CodeGroup>
  ```txt title="Policy example" lines wrap theme={null}
  proj/web-app:env/production:flag/*
  ```
</CodeGroup>

To learn more about policies, read [Using policies](/docs/home/account/roles/role-policies).

## Use the integration

After you configure the integration, LaunchDarkly events appear in Mezmo log statements similar to log statements from other sources. Data from LaunchDarkly is identified with the `launchdarkly` source. Additionally, they are marked with `env` and `app` values corresponding to the appropriate LaunchDarkly environment and project keys, respectively.

You can include LaunchDarkly events in your view by selecting the `launchdarkly` source from the selector at the top of the Mezmo page. Expand any of these log statements for more details.

LaunchDarkly events also include metadata by which you can filter.

For example, to only view log statements corresponding to the `demo-flag` flag, search for the query string `meta.flag_key:demo-flag`.