Stronger agentic coding
Z.ai reports a 50% gain over GLM-5.2 on its in-house Code Bench, and DeepSWE v1.1 up from 46.2 to 66.9. It was trained on long tasks that mirror real engineering work.
Z.ai
Operational· 100% uptime, 7 daysGLM-5.3 API
The GLM-5.3 API for coding agents and code security, 73% below Z.ai's list price
Price per 1M tokens73%off
- Input
- $0.38
$1.40 - Output
- $1.21
$4.40 - Cached input
- $0.038
Model ID
glm-5.3chat.py
from openai import OpenAIclient = OpenAI( base_url="https://api.zurelay.com/v1", api_key="YOUR_ZURELAY_KEY",)stream = client.chat.completions.create( model="glm-5.3", messages=[{"role": "user", "content": "Explain quicksort in two sentences."}], stream=True,)for chunk in stream: if chunk.choices: print(chunk.choices[0].delta.content or "", end="")Base URL https://api.zurelay.com/v1. Works with any OpenAI SDK.
- Context window
- 1M tokens
- Max output
- 128K tokens
- Input
- Text
- Output
- Text
- Released
- Aug 14, 2026
- Uptime, 7 days
- 100%
Pricing
GLM-5.3 API pricing. A fraction of the list price.
Pay as you go from prepaid credit, with no subscription and no minimum. Requests that fail are never billed.
| Rate | zurelay | Z.ai list | You save |
|---|---|---|---|
Input per 1M tokens | $0.38 | 73%off | |
Output per 1M tokens | $1.21 | 73%off | |
Cached input per 1M tokens | $0.038 | — | — |
One rate at every prompt length, up to the full 1M context window. Streaming, tool calls and structured outputs cost nothing extra.
Savings calculator
Move the sliders to your monthly usage.
Input tokens per month50M
Output tokens per month10M
zurelay
$31.10
Z.ai list price
$114.00
You save every month$82.90
$994.80 a year
Overview
What is GLM-5.3?
GLM-5.3 is Z.ai's flagship model for complex software engineering and long-running agents, with a 1M-token context window and up to 128K output tokens. The zurelay GLM-5.3 API serves the same model through one OpenAI-compatible endpoint, billed per token at 73% below Z.ai's list price.
GLM-5.3 is Z.ai's flagship model for complex coding and agent work. Z.ai announced it on August 14, 2026, first for its GLM Coding Plan, then opened the GLM-5.3 API and published the weights on Hugging Face later that month. The model reads and writes text, holds up to 1M tokens of context and writes up to 128K output tokens per request.
GLM-5.3 uses the same base model as GLM-5.2: a Mixture-of-Experts model with 744B total parameters and 40B active per token. Every gain comes from post-training on long, realistic work environments, some of which represent several days of work for an experienced engineer. Z.ai reports a 50% gain over GLM-5.2 on its in-house Z.ai Code Bench, and Terminal-Bench 3.0 rising from 4.6 to 28.3. It also spends fewer tokens: at max effort it averages about 75K output tokens per Code Bench task, against 96K for GLM-5.2.
Reasoning is always on. Z.ai's API takes a reasoning_effort of low, high or max, with max as the default and the setting Z.ai recommends for coding. Thinking can no longer be switched off, so requests that set thinking to disabled on older GLM models should move to low effort. The model supports function calling, structured JSON output, streaming and context caching. Z.ai also reports a jump in security work: 84.5% on the CyberGym vulnerability discovery benchmark, up from 77.2% for GLM-5.2.
On zurelay you call GLM-5.3 with the OpenAI SDK you already use: set the base URL to https://api.zurelay.com/v1 and the model to glm-5.3. You pay $0.38 per 1M input tokens and $1.21 per 1M output tokens, against Z.ai's list price of $1.40 and $4.40, with cached input at $0.038. The rate is the same at every prompt length, and you pay from prepaid credit with no subscription.
Strengths
Where GLM-5.3 shines. And what teams build with it.
Fewer tokens per task
At max effort GLM-5.3 averages about 75K output tokens per Code Bench task, against 96K for GLM-5.2, while scoring higher. At high effort it uses around 50K.
Vulnerability discovery
GLM-5.3 scores 84.5% on CyberGym, up from 77.2% for GLM-5.2. Working with security teams, Z.ai says it found 1,097 medium-to-high severity issues in real-world codebases.
1M tokens of context
A large repository, long build logs or a full agent trace fits in one request, with up to 128K output tokens for long patches and reports.
Use cases
Coding agents
Run repository-scale refactors, bug fixes and test loops in agent harnesses that call tools over many steps.
Terminal automation
Drive shell-based agents that build, test and debug in a sandbox. Z.ai reports its largest gains on Terminal-Bench 3.0.
Secure code review
Review source code for vulnerabilities and draft fixes before release. Z.ai built GLM-5.3 for white-box code review and vulnerability discovery.
Whole-codebase questions
Ask about architecture, call chains or a large diff across an entire project in one 1M-token request.
Get started
Call GLM-5.3 in three steps.
No waitlist and no new SDK. If your code already talks to OpenAI, it already talks to zurelay.
- 1
Create a key
Sign up, add credit and create an API key. Set a monthly budget or a rate limit per key if you like.
- 2
Point your SDK at zurelay
Change the base URL. Everything else in your code stays the same.
https://api.zurelay.com/v1 - 3
Use glm-5.3
Send chat completions as usual. Streaming, tool calls and usage reporting work as you expect.
glm-5.3
Works with the tools you already use
Compare
Similar models. All on the same key.
73%off
GLM-5.2
$0.38 / $1.21 per 1M tokens
Pick GLM-5.2 when you need thinking switched off or MIT-licensed weights; Z.ai lists both models at the same price.
GLM-5.2 API58%off
Kimi K3
$1.27 / $6.37 per 1M tokens
Pick Kimi K3 when your agent needs image input or you want Moonshot's larger 2.8T-parameter model for long-horizon coding.
Kimi K3 API65%off
Claude Fable 5
$3.50 / $17.50 per 1M tokens
Pick Claude Fable 5 when top coding results matter more than cost; Z.ai's own Code Bench still puts it ahead of GLM-5.3.
Claude Fable 5 APIFAQ
GLM-5.3 API questions.
Anything else, write to sales@zurelay.com and an engineer will answer.
How much does the GLM-5.3 API cost on zurelay?
GLM-5.3 costs $0.38 per 1M input tokens and $1.21 per 1M output tokens on zurelay, with cached input at $0.038. Z.ai's list price is $1.40 input and $4.40 output, so you save 73%. One rate applies at every prompt length.
Is there a cheaper GLM API than Z.ai's own?
Yes. zurelay serves the same glm-5.3 model at 73% below Z.ai's list price. You top up prepaid credit and pay only for the tokens you use, with no subscription or coding plan.
How do I call the GLM-5.3 API with the OpenAI SDK?
Install the official OpenAI SDK, set the base URL to https://api.zurelay.com/v1 and use your zurelay API key. Then pass model "glm-5.3" to chat.completions.create. Set reasoning_effort to low, high or max; max is the default and the one Z.ai recommends for coding.
What is the GLM-5.3 context window?
GLM-5.3 has a 1M-token context window and writes up to 128K output tokens per request. It takes text input only and returns text. If you need image input, look at Kimi K3.
What is GLM-5.3 best at?
Z.ai built GLM-5.3 for complex software engineering and long-running agents. It reports a 50% gain over GLM-5.2 on its in-house Code Bench and top open-model results on Terminal-Bench 3.0. It is also strong at code security work, with 84.5% on the CyberGym vulnerability discovery benchmark.
How is GLM-5.3 different from GLM-5.2?
GLM-5.3 keeps GLM-5.2's base model, 1M-token context and 128K output limit, and Z.ai lists both at the same price. The changes come from post-training: stronger coding, better security results and fewer output tokens per task. GLM-5.3 always reasons at low, high or max effort, while GLM-5.2 can switch thinking off.
Is GLM-5.3 open source?
The weights are on Hugging Face under the GLM-5.3 License. It allows commercial use, modification and redistribution. Only Model-as-a-Service operators with very large annual revenue must first pass a Z.ai security review.
Does the GLM-5.3 API support streaming and per-key limits?
Yes. Set stream: true to receive tokens as they are generated, and add stream_options.include_usage to get token counts in the final chunk. You can give each zurelay API key its own monthly budget and requests-per-minute cap. Failed requests are retried on another route and never billed.
Is GLM-5.3 on zurelay the same model Z.ai serves?
Yes. Requests go to glm-5.3 itself, never a smaller or substitute model. Output is sampled, so wording varies from run to run, just as it does on Z.ai's own API. zurelay is an independent service and is not affiliated with Z.ai.
More models on zurelay
All models- Claude Opus 5.5 API$1.40 / $7.00 per 1M tokens−65%
- GPT-6 Astra API$2.50 / $12.50 per 1M tokens−75%
- Nano Banana Pro APIfrom $0.035 per image−74%
- Nano Banana 2 APIfrom $0.025 per image−63%
- Claude Sonnet 5.5 API$0.80 / $4.00 per 1M tokens−60%
- GPT-6.1 Sol API$0.50 / $2.50 per 1M tokens−75%
- GPT-6 Sol API$0.50 / $2.50 per 1M tokens−75%
- GPT-6 Luna API$0.025 / $0.125 per 1M tokens−75%
- Grok 4.7 API$0.70 / $2.10 per 1M tokens−65%
- MiMo V2.6 Pro API$0.18 / $0.36 per 1M tokens−59%
- MiMo V2.6 Flash API$0.06 / $0.12 per 1M tokens−57%
- DeepSeek V4.1 Flash API$0.037 / $0.15 per 1M tokens−88%
- DeepSeek V4 Flash API$0.045 / $0.18 per 1M tokens−85%
- DeepSeek V4 Flash 0731 API$0.022 / $0.06 per 1M tokens−61%
- DeepSeek V4 Pro 0813 API$0.23 / $0.62 per 1M tokens−84%
- Claude Fable 5.1 API$3.50 / $17.50 per 1M tokens−65%
- Claude Fable 5 API$3.50 / $17.50 per 1M tokens−65%
- Claude Opus 5 API$1.75 / $8.75 per 1M tokens−65%
- Claude Opus 4.8 API$1.75 / $8.75 per 1M tokens−65%
- Claude Opus 4.7 API$1.78 / $8.93 per 1M tokens−64%
- Claude Opus 4.6 API$1.75 / $8.75 per 1M tokens−65%
- Claude Haiku 4.5 API$0.38 / $1.90 per 1M tokens−62%
- GPT-5.6 Sol API$1.14 / $5.70 per 1M tokens−72%
- GPT-5.6 Terra API$0.54 / $3.26 per 1M tokens−73%
- GPT-5.6 Luna API$0.08 / $0.49 per 1M tokens−59%
- Gemini 3.7 Flash API$0.32 / $1.59 per 1M tokens−58%
- Gemini 3.5 Flash-Lite API$0.12 / $1.04 per 1M tokens−58%
- Gemini 3.1 Flash-Lite API$0.10 / $0.59 per 1M tokens−61%
- GLM-5.2 API$0.38 / $1.21 per 1M tokens−73%
- Kimi K3 API$1.27 / $6.37 per 1M tokens−58%
- Qwen 3.8 Max API$1.20 / $3.60 per 1M tokens−40%
- Qwen 3.8 Flash API$0.07 / $0.22 per 1M tokens−53%
- Qwen 3.8 Omni Flash API$0.075 / $0.235 per 1M tokens−50%
- HY4 Preview API$0.40 / $1.20 per 1M tokens−52%
- MiniMax M2.7 API$0.13 / $0.51 per 1M tokens−57%
- GPT Image 2.5 Flare API$0.02 per image−62%
- GPT Image 2.5 Sunburst API$0.02 per image−62%
- GPT Image 2 API$0.02 per image−62%
- Seedance 2.5 APIfrom $0.14 per secondVideo
- Seedance 2.0 APIfrom $0.097 per secondVideo
- Seedance 2.0 Fast APIfrom $0.074 per secondVideo
- Seedance 2.0 Mini APIfrom $0.047 per secondVideo
Stop paying list price.
Start saving today.
Create a key in seconds, point the SDK you already use at zurelay, and every request costs up to 85% less from the first token.