> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.mixlayer.com/api-reference/inference-ap-is/completions-legacy/completions/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.mixlayer.com/_mcp/server.

# Create a text completion

POST https://models.mixlayer.ai/v1/completions
Content-Type: application/json

Completes a text prompt. Set `stream` to true to receive JSON chunks as server-sent events; the stream ends with `data: [DONE]`.

Reference: https://docs.mixlayer.com/api-reference/inference-ap-is/completions-legacy/completions

## Authentication

- `Authorization` header (bearer token, required) — Mixlayer API key or console user session supplied as a Bearer token.

## Request

### Body (application/json)

This endpoint expects a CompletionsRequest.

- `model` (string, required) — Model identifier to use for generation.
- `prompt` (string, required) — Text prompt to complete.
- `max_tokens` (integer, optional, nullable) — Maximum number of tokens to generate.
- `stop` (list of string, optional, nullable) — Strings that stop generation when encountered.
- `stream` (boolean, optional, default: false) — When true, return server-sent events and terminate with `data: [DONE]`.
- `stream_options` (StreamOptions, optional, nullable)
- `temperature` (float, optional, nullable) — Sampling temperature. Higher values make output more random.
- `top_k` (integer, optional, nullable) — Restricts sampling to the highest-probability tokens.

## Response

### 200

A complete response or a stream of completion chunks, selected by the request's `stream` field

- `choices` (list of CompletionChoice, required) — Generated completion choices.
- `created` (long, required) — Unix timestamp when the completion was created.
- `id` (string, required) — Unique identifier for the completion.
- `model` (string, required) — Model used to generate the completion.
- `object` (enum, required) — Object type, always `text_completion`.
  - Allowed values: `text_completion`
- `usage` (Usage, required) — Token usage for the request.

## Errors

### 400 Bad Request Error

Invalid request or malformed JSON

- `error` (OpenAIErrorDetails, required)

### 401 Unauthorized Error

Missing or invalid API key

- `error` (OpenAIErrorDetails, required)

### 402 Payment Required Error

Billing is required

- `error` (OpenAIErrorDetails, required)

### 403 Forbidden Error

The API key lacks inference permission

- `error` (OpenAIErrorDetails, required)

### 429 Too Many Requests Error

Rate limit exceeded

- `error` (OpenAIErrorDetails, required)

### 500 Internal Server Error

Generation failed

- `error` (OpenAIErrorDetails, required)

## Types

### StreamOptions

- `include_obfuscation` (boolean, optional, nullable) — Accepted for OpenAI compatibility; obfuscation is not added by the gateway.
- `include_usage` (boolean, optional, default: false) — Include a final usage-only chunk before the `[DONE]` event.

### CompletionChoice

- `finish_reason` (string, required) — Why generation stopped.
- `index` (integer, required) — Index of this choice in the response.
- `text` (string, required) — Generated completion text.

### Usage

- `completion_tokens` (integer, required) — Number of generated tokens.
- `prompt_tokens` (integer, required) — Number of input tokens.
- `prompt_tokens_details` (PromptTokensDetails, required) — Detailed input-token usage.
- `total_tokens` (integer, required) — Total input and generated tokens.
- `server_tool_use` (map from string to long, optional)

### OpenAIErrorDetails

- `message` (string, required)
- `type` (string, required)
- `code` (string, optional, nullable)

### PromptTokensDetails

- `audio_tokens` (integer, required) — Number of audio input tokens.
- `cached_tokens` (integer, required) — Number of cached input tokens.

## Examples

**Request**

```json
{
  "model": "string",
  "prompt": "string"
}
```

**Response**

```json
{
  "choices": [
    {
      "finish_reason": "string",
      "index": 1,
      "text": "string"
    }
  ],
  "created": 1,
  "id": "string",
  "model": "string",
  "object": "text_completion",
  "usage": {
    "completion_tokens": 1,
    "prompt_tokens": 1,
    "prompt_tokens_details": {
      "audio_tokens": 1,
      "cached_tokens": 1
    },
    "total_tokens": 1,
    "server_tool_use": {}
  }
}
```

**SDK Code**

```python
import requests

url = "https://models.mixlayer.ai/v1/completions"

payload = {
    "model": "string",
    "prompt": "string"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())
```

```javascript
const url = 'https://models.mixlayer.ai/v1/completions';
const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: '{"model":"string","prompt":"string"}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://models.mixlayer.ai/v1/completions"

	payload := strings.NewReader("{\n  \"model\": \"string\",\n  \"prompt\": \"string\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://models.mixlayer.ai/v1/completions")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"model\": \"string\",\n  \"prompt\": \"string\"\n}"

response = http.request(request)
puts response.read_body
```

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://models.mixlayer.ai/v1/completions")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"model\": \"string\",\n  \"prompt\": \"string\"\n}")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://models.mixlayer.ai/v1/completions', [
  'body' => '{
  "model": "string",
  "prompt": "string"
}',
  'headers' => [
    'Authorization' => 'Bearer <token>',
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```