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

# CometAPI

> Use the CometAPI LLM plugin in a Zero Runtime pipeline to access many models through one endpoint. Setup, options, and usage in Python and JavaScript.

CometAPI is an **LLM** plugin. It exposes many models behind a single OpenAI-compatible
endpoint, so you can switch models without changing providers. It takes the transcribed
conversation and generates the reply.

## Setup

Set your CometAPI key in the worker environment. Generate a key from the [CometAPI console](https://www.cometapi.com/):

```bash theme={null}
export COMETAPI_API_KEY=<key>
```

## Usage

Import the plugin and pass it to the pipeline's `llm` slot.

<CodeGroup>
  ```python Python theme={null}
  from zeroruntime.plugins import CometAPILLM

  llm = CometAPILLM(
      model="gpt-4o-mini",
      temperature=0.7,
  )

  # Pipeline(llm=llm, ...)
  ```

  ```typescript Node JS theme={null}
  import { CometAPILLM } from '@zeroruntime/js-sdk/plugins';

  const llm = CometAPILLM({
    model: 'gpt-4o-mini',
    temperature: 0.7,
  });

  // Pipeline({ llm, ... })
  ```
</CodeGroup>

## Configuration Options

*Constructor parameters for `CometAPILLM`. The Python and Node JS SDKs share these field names. CometAPI is OpenAI-compatible and built on the [OpenAI](/runtime-sdk/plugins/llm/openai) plugin.*

| Parameter | Type | Default | Description |
| - | - | - | - |
| `api_key` | `str` | `None` | CometAPI key. Falls back to the `COMETAPI_API_KEY` environment variable when unset. |
| `model` | `str` | `"gpt-4o-mini"` | Model used to generate replies. |
| `temperature` | `float` | `0.7` | Sampling randomness; lower is more deterministic. |
| `max_completion_tokens` | `int` | `None` | Caps the length of each reply. |

## Import paths

| SDK | Import | Constructor |
| - | - | - |
| Python | `from zeroruntime.plugins import CometAPILLM` | `CometAPILLM(...)` |
| Node JS | `import { CometAPILLM } from '@zeroruntime/js-sdk/plugins'` | `CometAPILLM({ ... })` |

The reply is streamed to the [text-to-speech](/runtime-sdk/plugins/tts/cartesia) plugin, which
synthesizes the agent's voice.


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