GLM 5.3 API
Z.ai reasoning flagship for complex software engineering, repository-scale context, and long-horizon agent tasks.
Provider: Z.ai | Model ID: glm-5-3 | Context Window: 1.0M tokens
On this model: 1.0M tokens context window, agentic workload class, 88% cached-input discount, routed through Z.ai infrastructure.
Pricing
₹160/1M input · ₹490/1M output. Pay-as-you-go micro-metered billing. UPI and cards accepted with zero minimum commitment.
| Token Type | Price (INR) |
|---|---|
| Input Tokens | ₹160/1M tokens |
| Output Tokens | ₹490/1M tokens |
| Prompt Caching Input | ₹20/1M tokens |
Why agentic workloads get expensive
Agent loops resend the whole conversation on every turn, and a failed tool call bills the entire history again. Three controls matter most: cap the loop iterations, trim tool output before it re-enters history, and set a realistic max_tokens instead of leaving the ceiling open.
Good fit for agentic coding
- Autonomous coding agents that read files, run tools, and iterate
- Multi-step workflow automation where the model calls your functions
- Long repository or document context that must stay resident across turns
- Internal developer tools that need reliable structured output
Model Specifications
| Model Identifier | glm-5-3 |
|---|---|
| Provider | Z.ai |
| Category | agentic |
| Context Window | 1.0M tokens |
| Output Pricing Tier | premium |
| API Protocol | OpenAI-compatible REST API (JSON) |
| Endpoint | https://api.luminoai.co.in/v1/chat/completions |
OpenAI-Compatible Integration
Drop into existing OpenAI SDK code by changing the base URL to https://api.luminoai.co.in/v1. The request shape below is the agentic coding pattern.
curl https://api.luminoai.co.in/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer $LUMINO_API_KEY" \
-d '{
"model": "glm-5-3",
"messages": [
{"role": "system", "content": "You are a helpful assistant."},
{"role": "user", "content": "Read the failing test, locate the bug, and return a patch."}
]
}'
GLM 5.3 API FAQ
Does GLM 5.3 support function calling?
Yes — send tools in the standard OpenAI tools array and the model returns tool calls in the same shape your existing client already parses.
What dominates the cost of an agent loop?
Input tokens, because the full history is resent every turn. Cached input pricing is what keeps long loops affordable.
How do I keep long sessions from drifting?
Keep the system prompt stable so the prefix stays cacheable, and summarise older turns instead of dropping them silently.
Explore all models in catalog | API Documentation | Test GLM 5.3 in Playground