> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter.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**.

![Enable Broadcast](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)

## 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.

![Opik Trace View](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)

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