GLM-5.3

Z.ai’s large model for complex coding and long agent tasks, built on the same base model as GLM-5.2.

Context window
1M tokens
Accepts
Text
Input per 1M tokens
$1.40
Output per 1M tokens
$4.40

Send your first request

Set LYCEUM_API_KEY to your API key, then run this request. Usage is billed to your account.

Base URL
https://api.lyceum.technology/openai/v1
Model ID
z-ai/glm-5.3
Request fields
model, messages, stream, max_tokens, tools, tool_choice

Documented request fields for this endpoint. See the documentation for model-specific controls and limits.

app.py · Install openai and set LYCEUM_API_KEY

import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["LYCEUM_API_KEY"],
    base_url="https://api.lyceum.technology/openai/v1",
)

response = client.chat.completions.create(
    model="z-ai/glm-5.3",
    messages=[{"role": "user", "content": "Hello!"}],
)

print(response.choices[0].message.content)

What it costs and how fast it runs

You pay only for the tokens you use. Speed figures come from our own status checks.

Token pricing

GLM-5.3: token prices in US dollars per million tokens
USD per million tokens
Input$1.40
Cached input$0.26
Output$4.40

No base fee. Caching applies only where listed. Check the model's processing region before sending data.

Speed on Lyceum

GLM-5.3: median speed in our status checks over the last 7 days
Last 7 days
Time to first token290 ms
Output speed82 tokens/s

Median over the last 7 days from our status checks: short requests. Measured 6 October 2026, 09:41 UTC. Reasoning tokens count towards both figures. Live status and availability

The model in detail

Checked against the sources below. Anything they don't state is left out.

Capabilities

Input and output
Text in, text out
Context window
1M tokens
Reasoning
On by default
Tool calling
Supported

Architecture and licence

Total parameters
744B
Active parameters
40B
Architecture
Mixture of experts
Released
14 August 2026

Availability

API model ID
z-ai/glm-5.3
Provider
Z.ai
Processing region
EU-hosted
Sources