GLM 4.5 Air
GLM 4.5 Air is Z.AI's efficiency-focused model released July 28, 2025. It delivers fast inference for high-volume workloads while keeping reasoning and coding capability at reduced cost compared to the full GLM-4.5. Your use is subject to Z.AI's Terms & Privacy Policies.
View API reference- Input and output price
- Input $0.20, Output $1.10, Per 1M tokens
- 24h uptime
- Loading AI Gateway uptime
import { streamText } from 'ai'
const result = streamText({ model: 'zai/glm-4.5-air', prompt: 'Why is the sky blue?'})Copy link to headingPlayground
Try out GLM 4.5 Air by Z.AI. Usage is billed to your team at API rates. Free users (those who haven't made a payment) get $5 of credits every 30 days.
GLM 4.5 Air
GLM 4.5 Air
Copy link to headingProviders
Route requests across multiple providers. Copy a provider slug to set your preference. Visit the docs for more info. Using a provider means you agree to their terms, listed under Legal.
Copy link to headingUptime24 hours
Direct request success rate on AI Gateway and per-provider. Visit the docs for more info.
Copy link to headingThroughput24 hours
P50 throughput on live AI Gateway traffic, in tokens per second (TPS). Visit the docs for more info.
Copy link to headingLatency24 hours
P50 time to first token (TTFT) on live AI Gateway traffic, in milliseconds. View the docs for more info.
Getting started
Call GLM 4.5 Air through AI Gateway with the AI SDK generateText and streamText functions, or through the OpenAI Chat Completions, OpenAI Responses, and Anthropic Messages APIs by changing the base URL. AI Gateway authenticates the request and routes it to an available provider.
Install the AI SDK (pnpm add ai dotenv), create an API key from the API Keys page, and set it as AI_GATEWAY_API_KEY in your environment. Full setup is covered in the text generation quickstart.
import { generateText } from 'ai';import 'dotenv/config';
async function main() { const result = await generateText({ model: 'zai/glm-4.5-air', prompt: 'Why is the sky blue?', });
console.log(result.text);}
main().catch(console.error);Top-level parameters
The same GLM 4.5 Air request in each API format AI Gateway supports.
import { generateText } from 'ai';import 'dotenv/config';
async function main() { const result = await generateText({ model: 'zai/glm-4.5-air', system: 'You are a concise technical assistant.', prompt: 'Summarize the tradeoffs between static generation and SSR.', maxOutputTokens: 1024, });
console.log(result.text);}
main().catch(console.error);Standard parameters like prompt, messages, temperature, and tools work as documented in the AI SDK docs. These are the parameters with model-specific behavior.
| Parameter | Type | Required | Description |
|---|---|---|---|
model | string | Yes | Model ID in the form creator/model, e.g. zai/glm-4.5-air. AI Gateway routes the request to an available provider. |
maxOutputTokens | number | No | Hard cap on generated tokens. GLM 4.5 Air supports up to 96,000 output tokens. Reasoning tokens count toward this limit. |
reasoning | 'provider-default' | 'none' | 'minimal' | 'low' | 'medium' | 'high' | 'xhigh' | No | Provider-agnostic reasoning effort, available in AI SDK 7 or later. Maps to the provider’s native reasoning configuration; reasoning settings under providerOptions take precedence when both are set. See the Reasoning section below. |
providerOptions | Record<string, JSONValue> | No | AI Gateway routing options under gateway, plus any provider-native options under the provider’s own namespace — see the table below. |
Input limits
| Input | Formats | Sources | Max count | Max size | Limits |
|---|---|---|---|---|---|
| Text | — | — | — | — | Prompt and response share the 128K-token context window |
Provider options
Set AI Gateway routing options under providerOptions.gateway. For provider-specific options, pass them under the provider’s namespace as documented by the AI SDK.
Learn more in the AI SDK provider docs.
import { generateText } from 'ai';import 'dotenv/config';
async function main() { const result = await generateText({ model: 'zai/glm-4.5-air', prompt: 'Why is the sky blue?', providerOptions: { gateway: { only: ['zai'], }, }, });
console.log(result.text);}
main().catch(console.error);These AI Gateway routing options apply to every model. Provider-specific options pass through under the provider’s own namespace (for example providerOptions.anthropic) exactly as documented by the AI SDK.
| Parameter | Type | Required | Description |
|---|---|---|---|
providerOptions.gateway.only | string[] | No | Restrict routing to these provider slugs. Requests fail over only within the listed providers. |
providerOptions.gateway.order | string[] | No | Preferred provider order. Listed providers are tried first; unlisted providers remain available as fallbacks. |
providerOptions.gateway.sort | 'cost' | 'ttft' | 'tps' | No | Rank candidate providers by price, time to first token, or tokens per second instead of the default routing order. |
providerOptions.gateway.zeroDataRetention | boolean | No | Route only to providers with a zero-data-retention policy for this model. |
Routing across providers
AI Gateway serves the same model through multiple providers and fails over automatically. order expresses a preference while keeping every provider eligible; only is a hard allowlist — if none of the listed providers are available the request fails instead of falling back.
Options under a provider's own namespace (for example providerOptions.anthropic) are forwarded to that provider with the request. Providers ignore option namespaces that don't apply to them, so it is safe to set provider options alongside gateway routing options.
Reasoning
AI Gateway bridges reasoning across every API format. The AI SDK exposes a provider-agnostic top-level reasoning level (none, minimal, low, medium, high, or xhigh); the Chat Completions and Responses formats take the same effort under reasoning.effort; and the Anthropic Messages format uses a native thinking token budget. Whichever you send, the gateway maps it to the target model’s native configuration, converting between effort levels and token budgets as needed. Reasoning-related settings under providerOptions take full precedence over the top-level reasoning value and are never merged. Reasoning tokens typically count toward your output-token usage, though how they’re reported and billed varies by provider.
Learn more in the AI Gateway reasoning guide.
import { generateText } from 'ai';import 'dotenv/config';
async function main() { const result = await generateText({ model: 'zai/glm-4.5-air', prompt: 'Explain the Monty Hall problem step by step.', reasoning: 'high', });
console.log(result.text);}
main().catch(console.error);Tool calling
Expose tools the model can call. Define each tool’s inputs with a Zod schema.
import { generateText, tool } from 'ai';import { z } from 'zod';import 'dotenv/config';
async function main() { const result = await generateText({ model: 'zai/glm-4.5-air', prompt: 'What is the weather in San Francisco?', tools: { getWeather: tool({ description: 'Get the current weather for a location', inputSchema: z.object({ location: z.string() }), execute: async ({ location }) => ({ location, temperatureC: 18 }), }), }, });
console.log(result.text);}
main().catch(console.error);Copy link to headingMore models by Z.AI
| Model |
|---|
| 1M | 2.9 s | 147 tps | $0.37/M | $1.25/M | Read$0.08/M | — | +1 | | 09/18/2026 | |||||
| 1M | 0.5 s | 147 tps | $0.08/M | $0.25/M | Read$0.01/M | — | +1 |    +17 | 08/26/2026 | |||||
| 1M | 0.1 s | 394 tps | $0.70/M+1 more | $2.20/M+1 more | Read$0.12/M | — |   +17 | 08/18/2026 | ||||||
| 1M | 0.3 s | 459 tps | $2.10/M | $6.60/M | Read$0.21/M | — |  | 06/23/2026 | ||||||
| 1M | 0.2 s | 442 tps | $0.49/M+1 more | $1.56/M+1 more | Read$0.09/M | — | +14 | 06/16/2026 | ||||||
| 200K | 1.2 s | 93 tps | $0.06/M | $0.40/M | Read$0.01/M | — | | 01/19/2026 |
Copy link to headingAbout GLM 4.5 Air
GLM 4.5 Air was released July 28, 2025 as the efficiency-optimized variant in Z.AI's GLM-4.5 generation. Where GLM-4.5 targets maximum capability, GLM 4.5 Air trades a degree of depth for faster inference and lower per-token cost, making it practical for high-throughput production pipelines.
The model retains the core reasoning, coding, and agentic capabilities of the GLM-4.5 family while operating at reduced computational overhead. This positions it for workloads where response latency and cost per request are primary constraints: classification, extraction, summarization, and conversational applications that process high volumes of requests.
GLM 4.5 Air supports the same context window of 128K tokens as the full GLM-4.5 model. Through AI Gateway, it benefits from unified API access, built-in observability, and intelligent provider routing with automatic retries.
Copy link to headingWhat To Consider When Choosing a Provider
- Configuration: GLM 4.5 Air is optimized for speed. For tasks requiring deep multi-step reasoning, the full GLM-4.5 or later models like GLM-5 may produce better results.
- Configuration: At $0.2 input and $1.1 output per million tokens, GLM 4.5 Air is designed for workloads where unit economics matter. Estimate your monthly token volume to compare total cost against heavier alternatives.
- Configuration: GLM 4.5 Air uses the same API interface as GLM-4.5, so switching between the two requires only changing the model identifier.
- Zero Data Retention: Zero Data Retention is offered on a per-provider and model basis. See the documentation for details.
- Authentication: AI Gateway authenticates requests using an API key or OIDC token. You do not need to manage provider credentials directly.
Copy link to headingWhen to Use GLM 4.5 Air
Best for
- High-volume production pipelines: Low latency and cost efficiency per request outweigh peak reasoning depth
- Classification and extraction tasks: Competent language understanding without extended chain-of-thought overhead
- Conversational applications: Many concurrent users where response speed directly affects user experience
- Summarization workflows: Large document sets where throughput determines pipeline feasibility
- Development and prototyping: Fast iteration cycles benefit from quick model responses
Consider alternatives when
- Deep reasoning needed: The full GLM-4.5 or GLM-5 provides deeper deliberation capabilities for complex multi-step planning
- Vision or image understanding: GLM-4.5V builds on GLM-4.5-Air with multimodal input support
- Advanced code generation: GLM-4.6 and GLM-4.7 include targeted coding improvements
- Lowest cost simple tasks: Evaluate flash-tier models in the GLM lineup when further capability tradeoffs are acceptable
Copy link to headingConclusion
GLM 4.5 Air fills the efficiency tier in Z.AI's GLM-4.5 generation. It offers the practical balance teams need when deploying language models at scale: broad general capability with the speed and cost profile that high-volume production demands.
Copy link to headingFrequently Asked Questions
How does GLM 4.5 Air compare to the full GLM-4.5?
GLM 4.5 Air is the lightweight variant optimized for faster inference and lower cost. GLM-4.5 provides deeper reasoning capability at higher per-token cost. Both share the same API surface and context window.
What is GLM 4.5 Air best suited for?
High-volume tasks where speed and cost matter: classification, extraction, summarization, and conversational applications. For deep reasoning tasks, consider the full GLM-4.5 or GLM-5.
What is the context window for GLM 4.5 Air?
128K tokens, matching the full GLM-4.5 model.
How do I switch between GLM 4.5 Air and GLM-4.5?
Change the model identifier in your API call. Both models share the same API interface, so no other integration changes are needed.
How do I authenticate with GLM 4.5 Air through AI Gateway?
AI Gateway provides a unified API key. Configure it in your environment and use the model identifier to route requests. No separate Z.AI account is required, though BYOK is supported.
Is GLM 4.5 Air suitable for agentic workflows?
Yes, for agent steps that prioritize speed over deep reasoning. For planning-heavy steps, route those to GLM-4.5 or GLM-5 while using GLM 4.5 Air for faster execution steps.
What is the pricing for GLM 4.5 Air?
Check the pricing panel on this page for today's numbers. AI Gateway tracks rates across every provider that serves GLM 4.5 Air.