---
title: Z.ai: GLM 5.1 — Long-Horizon LLM | ModelsLab
description: Access Z.ai: GLM 5.1 API for autonomous 8-hour tasks and coding. Try GLM 5.1 model now for agentic engineering.
url: https://modelslab-frontend-v2-927501783998.us-east4.run.app/zai-glm-51
canonical: https://modelslab-frontend-v2-927501783998.us-east4.run.app/zai-glm-51
type: website
component: Seo/ModelPage
generated_at: 2026-05-13T10:29:25.255983Z
---

Available now on ModelsLab · Language Model

Z.ai: GLM 5.1
Autonomous Tasks, 8 Hours
---

[Try Z.ai: GLM 5.1](/models/open_router/z-ai-glm-5.1) [API Documentation](https://docs.modelslab.com)

Deploy GLM 5.1 Power
---

Long-Horizon

### Sustained Execution

Handles single tasks autonomously up to 8 hours from planning to production.

Coding Strength

### Agentic Engineering

Matches Claude Opus 4.6 in coding and general capabilities with 200K context.

Deep Reasoning

### Enable Thinking Mode

Activates compulsory reasoning for complex tasks via thinking parameter.

Examples

See what Z.ai: GLM 5.1 can create
---

Copy any prompt below and try it yourself in the [playground](/models/open_router/z-ai-glm-5.1).

Code Refactor

“Refactor this Python function for better performance and add error handling: def process\_data(data): return sum(data)”

Tech Docs

“Write technical documentation for a REST API endpoint that handles user authentication with JWT tokens.”

System Design

“Design a scalable microservices architecture for an e-commerce platform including database schema.”

Debug Script

“Debug this bash script that fails on large files and optimize it: for file in \*.log; do grep error $file > output.txt; done”

For Developers

A few lines of code.
GLM 5.1. One Call.
---

ModelsLab handles the infrastructure: fast inference, auto-scaling, and a developer-friendly API. No GPU management needed.

- **Serverless:** scales to zero, scales to millions
- **Pay per token,** no minimums
- **Python and JavaScript SDKs,** plus REST API

[API Documentation ](https://docs.modelslab.com)

PythonJavaScriptcURL

Copy

```
<code>import requests

response = requests.post(
    "https://modelslab.com/api/v7/llm/chat/completions",
    json={
  "key": "YOUR_API_KEY",
  "prompt": "",
  "model_id": ""
}
)
print(response.json())</code>
```

FAQ

Common questions about Z.ai: GLM 5.1
---

[Read the docs ](https://docs.modelslab.com)

### What is Z.ai: GLM 5.1?

Z.ai: GLM 5.1 is the flagship LLM for long-horizon tasks. It executes autonomously up to 8 hours. Matches Claude Opus 4.6 in coding.

### How to use Z.ai: GLM 5.1 API?

Set model to glm-5.1 in chat completions endpoint. Use Bearer token auth at api.z.ai/api/paas/v4. Supports 200K context, 128K output.

### Is Z.ai: GLM 5.1 model good for coding?

Yes, excels in agentic engineering and real-world coding. Outperforms GPT-5.4 in sustained execution benchmarks.

### Z.ai: GLM 5.1 alternative to Claude?

Direct alternative with aligned capabilities. Use for complex reasoning via thinking enabled. Migrate by updating model ID.

### Z.ai: GLM 5.1 LLM context limits?

200K token context window. 131K max tokens output. Enable stream and tool_stream for real-time handling.

### z ai glm 5.1 model pricing?

Costs deducted at 1x quota off-peak, higher peak. Check Z.ai dashboard for API key usage. Free tier available.

Ready to create?
---

Start generating with Z.ai: GLM 5.1 on ModelsLab.

[Try Z.ai: GLM 5.1](/models/open_router/z-ai-glm-5.1) [API Documentation](https://docs.modelslab.com)

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*This markdown version is optimized for AI agents and LLMs.*

**Links:**
- [Website](https://modelslab.com)
- [API Documentation](https://docs.modelslab.com)
- [Blog](https://modelslab.com/blog)

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*Generated by ModelsLab - 2026-05-13*