> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://www.comet.com/docs/opik/llms.txt.

# Observability for Hermes with Opik

> Install and configure the opik-hermes plugin to export LLM, tool, and agent traces to Opik.

[Hermes](https://github.com/NousResearch/hermes-agent) can send trace data to Opik through the plugin package [`opik-hermes`](https://github.com/comet-ml/opik-hermes).

This integration captures:

* A root trace per agent turn, organized by Hermes `session_id`
* LLM spans (`type=llm`): messages, assistant output, model/provider, token usage, and USD cost
* Tool spans (`type=tool`): tool arguments and results

## Prerequisites

* The [Hermes](https://github.com/NousResearch/hermes-agent) agent framework installed.
* Opik project/workspace details (for cloud or enterprise deployments).

## Setup

#### 1. Install the plugin

```bash
pip install opik-hermes
```

Installing the package automatically registers the plugin with Hermes.

#### 2. Enable the plugin

Add `opik` to the enabled plugins in `~/.hermes/config.yaml`:

```yaml
plugins:
  enabled: [opik]
```

#### 3. Configure Opik credentials

Set the Opik environment variables in `~/.hermes/.env`.

For a local open-source Opik deployment:

```bash
OPIK_URL_OVERRIDE=http://localhost:5173/api
OPIK_PROJECT_NAME=hermes
```

For Comet-hosted Opik:

```bash
OPIK_API_KEY=your-api-key
OPIK_WORKSPACE=your-workspace
```

## Validate setup

Run a Hermes chat session and verify traces appear in the configured Opik project dashboard.

## Next step

For OTEL-native pipelines, see [OpenTelemetry integration](/integrations/opentelemetry).