GLM-5.1 API
About
Build advanced reasoning agents with GLM-5.1, a specialized AI model optimized for complex logic and chain-of-thought tasks. This model delivers available completely free of charge, native tool calling support. Access GLM-5.1 via the Alibaba Token Plan API with up to 128K output tokens.
Capabilities
Input Modalities
text
Output Modalities
text
Reasoning
Yes
Structured Output
Yes
Tool Use
Yes
WeightsClosed
Temperature
Adjustable
Attachment
Not Supported
Limits
Context Window
203K
Tokens
Input Limit
203K
Tokens
Max Output
128K
Tokens
Pricing
Standard (per 1M tokens)
Input
Free
Output
Free
Caching (per 1M tokens)
Read
Free
Write
Free
Frequently Asked Questions
GLM-5.1 by Alibaba Token Plan costs Free per 1M input tokens and Free per 1M output tokens. Cached reads cost Free per 1M tokens. Cache writes cost Free per 1M tokens.
Model Details
API Integration
NPM Package
@ai-sdk/openai-compatible
Environment Variables
ALIBABA_TOKEN_PLAN_API_KEY
API Base URL
https://token-plan.ap-southeast-1.maas.aliyuncs.com/compatible-mode/v1