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

# Comet Opik

> Send traces to Comet Opik

[Comet Opik](https://www.comet.com/site/products/opik/) is an open-source platform for evaluating, testing, and monitoring LLM applications.

## Step 1: Get your Opik credentials

In Comet, set up your Opik workspace and project:

1. Log in to your Comet account
2. Create or select a workspace for your LLM traces
3. Create a project within the workspace
4. Go to **Settings > API Keys** to create or copy your API key

## Step 2: Enable Broadcast in OpenRouter

Go to [Settings > Observability](https://openrouter.ai/settings/observability) and toggle **Enable Broadcast**.

<Frame>
  <img src="https://mintcdn.com/openrouter-d02e98a0/PSwwwiCqAD_BNeni/assets/guides/features/broadcast/arize/broadcast-enable.png?fit=max&auto=format&n=PSwwwiCqAD_BNeni&q=85&s=a48ecd5df85b4e6f3982c8402671f631" alt="Enable Broadcast" width="2692" height="1296" data-path="assets/guides/features/broadcast/arize/broadcast-enable.png" />
</Frame>

## Step 3: Configure Comet Opik

Click the edit icon next to **Comet Opik** and enter:

* **Api Key**: Your Comet API key (starts with `opik_...`)
* **Workspace**: Your Comet workspace name
* **Project Name**: The project name where traces will be logged

## Step 4: Test and save

Click **Test Connection** to verify the setup. The configuration only saves if the test passes.

## Step 5: Send a test trace

Make an API request through OpenRouter and view the trace in your Opik
project dashboard.

<Frame>
  <img src="https://mintcdn.com/openrouter-d02e98a0/PSwwwiCqAD_BNeni/assets/guides/features/broadcast/opik/broadcast-opik-trace.png?fit=max&auto=format&n=PSwwwiCqAD_BNeni&q=85&s=a1efdbc1b136ceccc4546078f5cad6b0" alt="Opik Trace View" width="3368" height="1650" data-path="assets/guides/features/broadcast/opik/broadcast-opik-trace.png" />
</Frame>

## Custom Metadata

Comet Opik supports custom metadata on both traces and spans for organizing and filtering your LLM evaluations.

### Supported Metadata Keys

| Key               | Opik Mapping                           | Description                                  |
| ----------------- | -------------------------------------- | -------------------------------------------- |
| `trace_id`        | Trace metadata (`openrouter_trace_id`) | Group multiple requests into a single trace  |
| `trace_name`      | Trace Name                             | Custom name displayed in the Opik trace list |
| `span_name`       | Span Name                              | Name for intermediate spans in the hierarchy |
| `generation_name` | Span Name                              | Name for the LLM generation span             |

### Example

```json lines theme={null}
{
  "model": "openai/gpt-4o",
  "messages": [{ "role": "user", "content": "Evaluate this response..." }],
  "user": "user_12345",
  "session_id": "session_abc",
  "trace": {
    "trace_name": "Response Quality Eval",
    "generation_name": "Quality Assessment",
    "eval_suite": "quality_v2",
    "test_case_id": "tc_001"
  }
}
```

### Additional Context

* Custom metadata keys from `trace` are included in both the trace and span metadata objects
* Cost information (input, output, total) is automatically added to span metadata
* Model parameters and finish reasons are included in span metadata when available
* The `user` field maps to user identification in trace metadata
* Opik uses UUIDv7 format for trace and span IDs internally; original OpenRouter IDs are stored in metadata as `openrouter_trace_id` and `openrouter_observation_id`

## Privacy Mode

When [Privacy Mode](/guides/features/broadcast#privacy-mode) is enabled for this destination, prompt and completion content is excluded from traces. All other trace data — token usage, costs, timing, model information, and custom metadata — is still sent normally. See [Privacy Mode](/guides/features/broadcast#privacy-mode) for details.