How do I use GLM 5.3 through YepAPI?

Sign up for a free API key, then send requests to the /v1/ai/chat endpoint.

Z.aiText Generation/v1/ai/chatReasoning

GLM 5.3

Access GLM 5.3 through one API key. Z.ai GLM 5.3 Reasoning for Engineering.

GLM 5.3 is a large-scale reasoning model from Z.ai, built for complex software engineering and long-horizon agent tasks. GLM 5.3 is one of the best value models on the platform for coding agents and batch reasoning: flagship-class engineering ability at budget rates.

Full Docs Get API Key — Free $5 Credit

No credit card required. Takes 30 seconds.

2,400+

Developers

1.2M+

API calls served

100+

Endpoints

$0.01

Per call

Yep, that's it.

Try it live

Send a message and see GLM 5.3 respond in real time.

POST/v1/ai/chatz-ai/glm-5.3

Message *

Max Tokens

Maximum tokens in the response.

Stream

Real-time tokens

Hit "Send Request" to see the response

Context Window

1.3M tokens

Max Output

944K tokens

Input Price

$0.35 / 1M tokens

Output Price

$1.10 / 1M tokens

Strengths

✓

Flagship ability at budget price

Improves on GLM 5.2 at $0.37 / $1.10 per 1M tokens, a fraction of its predecessor.

✓

Long-horizon agents

Built for complex software engineering and agent runs spanning many steps.

✓

1.3M context, very large output

Handles up to 1,310,720 input tokens and returns up to 943,718 output tokens per call.

✓

Tools and structured output

Function calling and JSON schema outputs.

Quick start

Copy this snippet and start making calls with GLM 5.3.

const res = await fetch('https://api.yepapi.com/v1/ai/chat', {
  method: 'POST',
  headers: {
    'x-api-key': 'YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "model": "z-ai/glm-5.3",
    "messages": [
      {
        "role": "user",
        "content": "Explain API gateways in 2 sentences."
      }
    ],
    "maxTokens": 256
  }),
});
const { data } = await res.json();
console.log(data.message.content);

Why use GLM 5.3 through YepAPI?

✓One API key for all models — no separate accounts

✓OpenAI SDK compatible — just change the base URL

✓No monthly minimums — pay per token

✓Switch models with one line of code

✓Full provider passthrough — citations, search results, and all extras included

✓Streaming and non-streaming support on every model

✓Works with Cursor, Claude, LangChain, and any LLM tool

✓Unified billing across all providers

GLM 5.3 API — pricing, context window & access

GLM 5.3 is a large-scale reasoning model from Z.ai, built for complex software engineering and long-horizon agent tasks. It pairs a 1,310,720-token context window with up to 943,718 output tokens per response, at $0.37 per 1M input and $1.10 per 1M output tokens through YepAPI.

Through YepAPI you call GLM 5.3 on an OpenAI-compatible endpoint with a single key — the same key that reaches GPT-6, Claude, Gemini, Grok and the SEO, SERP and scraping APIs. Input: text.

What is GLM 5.3?

GLM 5.3 is a large-scale reasoning model from Z.ai, built for complex software engineering and long-horizon agent tasks. It supports text input and output with a 1,310,720-token context window and up to 943,718 output tokens, and it improves on GLM 5.2 at a far lower price: $0.37 / $1.10 per 1M tokens. It accepts text as input, handles up to 1,310,720 tokens of context and returns up to 943,718 output tokens per call.

Build with GLM 5.3 via YepAPI

YepAPI serves GLM 5.3 on the OpenAI-compatible /v1/ai/chat endpoint. Point your base URL at YepAPI, add your key, and set the model string to glm-5.3 (or the full z-ai/glm-5.3). Function calling, structured outputs and reasoning settings pass straight through, and switching to any other model on the platform is a one-string change per request.

GLM 5.3 API pricing — $0.37 / 1M input, $1.10 / 1M output

GLM 5.3 costs $0.37 per 1M input tokens and $1.10 per 1M output tokens through YepAPI, pay per token with no minimums. Failed calls are never charged, and every request is itemised in your dashboard API Logs so you can see exactly what a very long response cost.

GLM 5.3 use cases

GLM 5.3 is one of the best value models on the platform for coding agents and batch reasoning: flagship-class engineering ability at budget rates.

Try GLM 5.3 free

Every new YepAPI account includes $5 in free credit with no card required — enough to test GLM 5.3 on your own prompts before committing to paid usage. Create an account, copy your key, and call glm-5.3 right away.