# GLM-4.5-Air

> GLM-4.5-Air is a lightweight Z.ai text model purpose-built for agent-centric applications, with open weights.

## Key facts

- Model author: Z.ai
- Input: $0.20 per 1M tokens
- Output: $1.10 per 1M tokens
- Cached input: $0.03 per 1M tokens
- Context window: 128,000 tokens
- Maximum output: 96,000 tokens
- Input modalities: text
- Output modalities: text
- Capabilities: reasoning, tools
- Released: 2025-07-28
- Knowledge cutoff: 2024-12-31
- Model IDs: `z-ai/glm-4.5-air`
- Model page: https://www.realrelay.ai/model/z-ai/glm-4.5-air

## Overview

GLM-4.5-Air is a lightweight text model from Z.ai, purpose-built for agent-centric applications. Z.ai lists it as cost-effective and high-performance, which makes it a fit for workloads that send many requests. It supports reasoning and tool calling, and it takes text in and returns text out.

GLM-4.5-Air has a 128K-token context window and can generate up to 96K output tokens. It accepts text input and returns text output. Its knowledge cutoff is December 31, 2024. It was released on July 28, 2025. Its weights are openly available.

## Capabilities

GLM-4.5-Air supports reasoning and tool calling. Z.ai summarizes its strengths as cost-effective, lightweight and high-performance.

## Pricing

GLM-4.5-Air costs $0.20 per 1M input tokens and $1.10 per 1M output tokens. Cache reads cost $0.03 per 1M tokens.

GLM-4.5-Air is available through RealRelay's OpenAI-compatible API.

## Use cases

Use GLM-4.5-Air for agent workloads that make many model calls, such as tool-using assistants and multi-step task runners, where a lightweight, cost-effective model keeps each call affordable.

With reasoning and tool calling available, it also handles routine analysis and automation tasks that need more than a plain chat reply, inside a 128K-token context window.

## Call it

OpenAI-compatible chat completions:

```bash
curl https://www.realrelay.ai/v1/chat/completions \
  -H "Authorization: Bearer $REALRELAY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "z-ai/glm-4.5-air", "messages": [{"role": "user", "content": "Hello"}]}'
```

## FAQ

### What is GLM-4.5-Air?

GLM-4.5-Air is a lightweight Z.ai text model purpose-built for agent-centric applications, with open weights.

### How much does GLM-4.5-Air cost?

GLM-4.5-Air costs $0.20 per 1M input tokens and $1.10 per 1M output tokens, with cache reads at $0.03 per 1M tokens.

### What is the context window of GLM-4.5-Air?

GLM-4.5-Air has a 128K-token context window and can generate up to 96K output tokens.

### What inputs and outputs does GLM-4.5-Air support?

GLM-4.5-Air accepts text input and returns text output.

### Does GLM-4.5-Air support tool calling?

Yes. GLM-4.5-Air supports tool calling, along with reasoning.

### When was GLM-4.5-Air released?

GLM-4.5-Air was released on July 28, 2025.

### How do I call GLM-4.5-Air via the API?

Send requests to RealRelay's OpenAI-compatible API and use the model ID z-ai/glm-4.5-air.