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

# GLM-5.3 FlashX

> Faster-serving GLM-5.3 Flash variant for multimodal coding and long-running agents.

Faster-serving GLM-5.3 Flash variant for multimodal coding and long-running agents.

## Model Information

| Field        | Description               |
| ------------ | ------------------------- |
| `model`      | glm-5.3-flashx            |
| `context`    | 1M tokens                 |
| `max output` | 128K tokens               |
| `endpoint`   | POST /v1/chat/completions |

Context and output sizes describe the model specification. Effective request limits, availability, and billing depend on the MixRoute route.

## Capabilities and Usage

* The model supports native text, image, video, and file understanding and produces text. Input transport depends on the API route.
* Thinking cannot be disabled: thinking.type supports enabled only. Images in Chat Completions use messages\[].content\[] blocks with type=image\_url and image\_url.url.
* FlashX is a separate model ID from glm-5.3-flash; throughput depends on the serving route and workload.

## Request Example

Set `MIXROUTE_API_KEY` before making the request.

```bash theme={null}
curl --request POST "https://api.mixroute.ai/v1/chat/completions" \
  --header "Authorization: Bearer $MIXROUTE_API_KEY" \
  --header "Content-Type: application/json" \
  --data '{
  "model": "glm-5.3-flashx",
  "messages": [
    {
      "role": "user",
      "content": "Explain the tradeoffs of database indexes."
    }
  ],
  "max_tokens": 1024
}'
```

## Request Fields

| Field        | Description                                           |
| ------------ | ----------------------------------------------------- |
| `model`      | Required. Use the exact model ID above.               |
| `messages`   | Required conversation messages with role and content. |
| `max_tokens` | Optional output-token budget.                         |

Complete request format: [chat-openai](/en/api-reference/endpoint/chat-openai).