Z.aiText Generation/v1/ai/chat

GLM 5.3 FlashX API

Access GLM 5.3 FlashX through one API key. Z.ai GLM 5.3 Flash at 200 tok/s.

GLM 5.3 FlashX is the high-speed variant of Z.ai's GLM 5.3 Flash, a native multimodal model delivering inference speeds of up to 200 tokens per second on the same hybrid sparse and linear attention architecture. FlashX is for interactive experiences on top of GLM 5.3 Flash — live coding assistants, chat — where 200 tokens per second changes how the product feels.

Full Docs Get API Key

Takes 30 seconds.

GLM 5.3 FlashX API pricing

Pay per request from your YepAPI balance — no subscription, no monthly minimum. Prices updated October 23, 2026.

Token type	Price
Input	$0.55 / 1M tokens
Output	$1.85 / 1M tokens
Context window	1.0M tokens

What it costs	Per job	Per 1,000
Chat reply1K input + 500 output tokens	$0.0015	$1.48
RAG answer8K input + 800 output tokens	$0.0059	$5.88
Agent step with tools30K input + 2K output tokens	$0.02	$20.20
Long document summary100K input + 2K output tokens	$0.059	$58.70

4,900+

Developers

2.3M+

API calls served

184

Endpoints

$0.01

Per call

Yep, that's it.

Try it live

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

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

Message *

Max Tokens

Maximum tokens in the response.

Stream

Real-time tokens

Hit "Send Request" to see the response

GLM 5.3 FlashX specs

Provider	Z.ai
Model ID	z-ai/glm-5.3-flashx
Endpoint	/v1/ai/chat
Type	Text Generation
Context window	1.05M tokens
Max output	131K tokens
Reasoning	No
OpenAI-compatible	Yes — /v1/ai/chat/completions

How to get a GLM 5.3 FlashX API key

1
Create an account
Sign up at yepapi.com with Google or email. It takes about 30 seconds.
2
Create an API key
Open the dashboard, go to API Keys and create a key. Copy it — it starts with yep_sk_.
3
Call GLM 5.3 FlashX
Send a request to /v1/ai/chat with the x-api-key header and model "z-ai/glm-5.3-flashx".
4
Pay as you go
Usage is billed per request from your balance. Top up any amount; there is no subscription.

Strengths

✓

Up to 200 tokens/s

The fast-serving edition of GLM 5.3 Flash.

✓

Native multimodal

Accepts text, images and video.

✓

1M context, 131K output

Handles up to 1,048,576 input tokens and returns up to 131,072 output tokens per call.

✓

Low cost for the speed

$0.55 per 1M input and $1.85 per 1M output tokens.

Quick start

Copy this snippet and start making calls with GLM 5.3 FlashX.

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-flashx",
    "messages": [
      {
        "role": "user",
        "content": "Explain API gateways in 2 sentences."
      }
    ],
    "maxTokens": 256
  }),
});
const { data } = await res.json();
console.log(data.message.content);

GLM 5.3 FlashX vs similar models

Every model below runs on the same API key — switch by changing the model ID.

Model	Provider	Price	Context
GLM 5.3 FlashX	Z.ai	$0.55 in / $1.85 out per 1M	1.0M
GLM 5.3 Flash	Z.ai	$0.22 in / $0.74 out per 1M	1.0M
GLM 5	Z.ai	$1.48 in / $4.73 out per 1M	205K
GLM 5 Turbo	Z.ai	$1.77 in / $5.91 out per 1M	203K
GLM 5.3	Z.ai	$2.07 in / $6.50 out per 1M	1.0M
GLM 5.2	Z.ai	$2.07 in / $6.50 out per 1M	1.0M
Nemotron 3 Super	NVIDIA	$0 in / $0 out per 1M	262K
Qwen3.7 Flash	Qwen	$0.04 in / $0.19 out per 1M	1M

Why use GLM 5.3 FlashX 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 FlashX API — pricing, context window & access

GLM 5.3 FlashX is the high-speed variant of Z.ai's GLM 5.3 Flash, a native multimodal model delivering inference speeds of up to 200 tokens per second on the same hybrid sparse and linear attention architecture. It pairs a 1,048,576-token context window with up to 131,072 output tokens per response, at $0.55 per 1M input and $1.85 per 1M output tokens through YepAPI.

Through YepAPI you call GLM 5.3 FlashX 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, images, video.

What is GLM 5.3 FlashX?

GLM 5.3 FlashX is the high-speed variant of Z.ai's GLM 5.3 Flash, a native multimodal model delivering inference speeds of up to 200 tokens per second on the same hybrid sparse and linear attention architecture. It accepts text, image and video with a 1,048,576-token context window and up to 131,072 output tokens at $0.55 / $1.85 per 1M tokens. It accepts text, images, video as input, handles up to 1,048,576 tokens of context and returns up to 131,072 output tokens per call.

Build with GLM 5.3 FlashX via YepAPI

YepAPI serves GLM 5.3 FlashX 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-flashx (or the full z-ai/glm-5.3-flashx). 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 FlashX API pricing — $0.55 / 1M input, $1.85 / 1M output

GLM 5.3 FlashX costs $0.55 per 1M input tokens and $1.85 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 131,072-token response cost.

GLM 5.3 FlashX use cases

FlashX is for interactive experiences on top of GLM 5.3 Flash — live coding assistants, chat — where 200 tokens per second changes how the product feels.

Start generating in 30 seconds

Pay per call, no subscriptions.

Get API Key

What developers say

“Switched from SerpAPI and cut our SERP costs by 80%. Same data quality, way simpler billing.”
Marcus T.
SEO Platform Founder

“One API key for AI models, SERP data, and web scraping. Saved us from managing 4 separate providers.”
Priya S.
Full-Stack Developer

“The $5 free credit let us prototype our entire rank tracking feature before committing. No other API does that.”
Jake R.
Indie Hacker

Frequently asked questions

GLM 5.3 FlashX costs $0.55 per 1M input tokens and $1.85 per 1M output tokens through YepAPI, billed per request with no monthly fee. For example, a chat reply (1K input + 500 output tokens) costs about $0.0015.

Sign up at yepapi.com (Google or email, about 30 seconds), open the dashboard and create an API key. The same key works for GLM 5.3 FlashX and every other model — no separate Z.ai account or waitlist.

Use "z-ai/glm-5.3-flashx" as the model on /v1/ai/chat. The short alias "glm-5.3-flashx" also works.

Yes. Point the OpenAI SDK at https://api.yepapi.com/v1/ai with your YepAPI key and set model to "z-ai/glm-5.3-flashx". Streaming works the same way, so existing OpenAI code only needs the base URL and key changed.

GLM 5.3 FlashX supports a 1.0M token context window with up to 131K output tokens per request.