---
title: Chat Completions
description: OpenAI-compatible chat completions API with streaming support for elizaOS Cloud.
---

# Chat Completions

OpenAI-compatible chat completions endpoint for conversational AI.

## Create Chat Completion

<div className="api-endpoint">
  <span className="method-badge method-badge-post">POST</span>
  <span className="path">/api/v1/chat/completions</span>
</div>

Generate a chat completion response from the model.

### Request

<Tabs>
  <Tab title="cURL">

```bash
curl -X POST "https://elizacloud.ai/api/v1/chat/completions" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-oss-120b",
    "messages": [
      {"role": "system", "content": "You are a helpful assistant."},
      {"role": "user", "content": "Hello!"}
    ],
    "temperature": 0.7
  }'
```
  </Tab>
  <Tab title="JavaScript">

```javascript
const response = await fetch('https://elizacloud.ai/api/v1/chat/completions', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    model: 'gpt-oss-120b',
    messages: [
      { role: 'system', content: 'You are a helpful assistant.' },
      { role: 'user', content: 'Hello!' }
    ],
    temperature: 0.7,
  }),
});

const data = await response.json();
console.log(data.choices[0].message.content);

```
  </Tab>
  <Tab title="Python">

```python
import requests

response = requests.post(
    'https://elizacloud.ai/api/v1/chat/completions',
    headers={
        'Authorization': 'Bearer YOUR_API_KEY',
        'Content-Type': 'application/json',
    },
    json={
        'model': 'gpt-oss-120b',
        'messages': [
            {'role': 'system', 'content': 'You are a helpful assistant.'},
            {'role': 'user', 'content': 'Hello!'}
        ],
        'temperature': 0.7,
    }
)

data = response.json()
print(data['choices'][0]['message']['content'])
```
  </Tab>
</Tabs>

### Parameters

| Parameter           | Type         | Required | Description                            |
| ------------------- | ------------ | -------- | -------------------------------------- |
| `model`             | string       | ✓        | Model ID or agent ID                   |
| `messages`          | array        | ✓        | Array of message objects               |
| `temperature`       | number       |          | Sampling temperature (0-2). Default: 1 |
| `max_tokens`        | integer      |          | Maximum tokens to generate             |
| `stream`            | boolean      |          | Stream response chunks. Default: false |
| `top_p`             | number       |          | Nucleus sampling parameter (0-1)       |
| `frequency_penalty` | number       |          | Frequency penalty (-2 to 2)            |
| `presence_penalty`  | number       |          | Presence penalty (-2 to 2)             |
| `stop`              | string/array |          | Stop sequences                         |
| `user`              | string       |          | Unique user identifier                 |

### Message Object

| Field     | Type   | Required | Description                              |
| --------- | ------ | -------- | ---------------------------------------- |
| `role`    | string | ✓        | `system`, `user`, `assistant`, or `tool` |
| `content` | string | ✓        | Message content                          |
| `name`    | string |          | Optional name for the participant        |

### Response

```json
{
  "id": "chatcmpl-abc123",
  "object": "chat.completion",
  "created": 1705312800,
  "model": "gpt-oss-120b",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Hello! How can I help you today?"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 20,
    "completion_tokens": 10,
    "total_tokens": 30
  }
}
```

---

## Streaming

Enable streaming for real-time responses by setting `stream: true`.

### Streaming Request

```javascript
const response = await fetch("https://elizacloud.ai/api/v1/chat/completions", {
  method: "POST",
  headers: {
    Authorization: "Bearer YOUR_API_KEY",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    model: "gpt-oss-120b",
    messages: [{ role: "user", content: "Tell me a story" }],
    stream: true,
  }),
});

const reader = response.body.getReader();
const decoder = new TextDecoder();

while (true) {
  const { done, value } = await reader.read();
  if (done) break;

  const chunk = decoder.decode(value);
  const lines = chunk.split("\n").filter((line) => line.startsWith("data: "));

  for (const line of lines) {
    const data = line.slice(6);
    if (data === "[DONE]") continue;
    const parsed = JSON.parse(data);
    process.stdout.write(parsed.choices[0]?.delta?.content || "");
  }
}
```

---

## Using with Agents

You can use an agent ID as the model to chat with your custom AI agents:

```json
{
  "model": "agent_abc123",
  "messages": [{ "role": "user", "content": "Hello!" }]
}
```

<Info>
  The agent's personality, system prompt, and configured model will be used
  automatically.
</Info>

---

## Available Models

Model availability changes as provider catalogs and account configuration
change. See the [Models API](/cloud/api/models) or API Explorer for the current
catalog and defaults.