GLM-5.3
Z.ai’s open flagship for coding agents and security work.
About GLM-5.3
GLM-5.3 is Z.ai’s top model, and an unusual kind of upgrade: the base model is the same as GLM-5.2, and every gain came from further training on top of it. The gains are large where Z.ai aimed them — 66.9% on DeepSWE, up from 46.2%, and 84.5% on the CyberGym security benchmark, which Z.ai puts ahead of Claude Fable 5.
It always thinks before answering, at low, high or max effort (max is the default), and handles a million-token context. The weights are open under Z.ai’s own licence, which asks the very largest companies to pass a security review first.
Where it’s strong
Long coding agents that work through a large change.
Security analysis and defensive cyber work.
Command-line automation agents.
Where to be careful
Every call reasons — there is no fast mode — so simple requests are slower and dearer than they need to be.
Z.ai’s headline coding gain is on a private benchmark whose method is not published.
Text only.
Price
For scale: 1,000 requests of about 3,000 tokens in and 1,000 out cost $7.83 — a long prompt and a page of answer each. Every rate is published and stays the same from one request to the next. See every model.
Specs
glm-5.3Call it
Use the OpenAI SDK you already have — point it at Roar AI and name the model. Read the docs.
from openai import OpenAI
client = OpenAI(base_url="https://api.roar-ai.com/v1", api_key="roar_live_…")
reply = client.chat.completions.create(
model="glm-5.3",
messages=[{"role": "user", "content": "Summarise this contract in plain English."}],
)Compare GLM-5.3
Questions
How much does GLM-5.3 cost?
Input is $1.274 per 1M tokens; output is $4.004 per 1M tokens. For scale, 1,000 requests of about 3,000 tokens in and 1,000 out cost $7.83. The rate is published and does not change from one request to the next.
Can I use GLM-5.3 alongside other models?
Yes. Every model on Roar AI is on the same API key and the same monthly invoice, so switching from GLM-5.3 to another model is a change to one word in your code.
Is GLM-5.3 open source?
Its weights are open under the GLM-5.3 License licence, so you could run it yourself. Through Roar AI you call it like any other model, with no servers to manage.