Z.AI: GLM-5.1

Name: GLM-5.1 API
Brand: Zai

stable

GLM-5.1 is available through Everstack's OpenAI-compatible gateway with routing, fallback, retries, and observability.

glm-5.1glmreleased Apr 7, 2026

Provider Quick start

Context

200K

tokens

Max output

131.1K

tokens

Input

$1.40

per 1M

Output

$4.40

per 1M

Activity

Daily period usage

Aggregated managed Everstack traffic. Buckets below 5 tenants or 100 requests are withheld.

Providers

ProviderContextInput /MOutput /M

Pricing

Item	Price	Unit
Input	$1.40	per 1M tokens
Output	$4.40	per 1M tokens
Cache read	$0.26	per 1M tokens
Cache write	-	per 1M tokens

Performance

Reliability

Compare

Compare usage and performance

Place this model beside up to three other catalog models.

Capabilities

Modalities

Input

Output

Details

Model ID: glm-5.1
Family: glm
Status: stable
Knowledge: -
Released: Apr 7, 2026

Gateway Config

API: 2024-01-01
Auth: ZHIPU_API_KEY
Discovery: static
Provider type: static

Quick Start

index.ts

import Everstack from "@everstack/node";const client = new Everstack({  apiKey: process.env.EVERSTACK_API_KEY!,  baseUrl: "https://{instance}.{region}.everstack.ai",});const completion = await client.chat.completions.create({  model: "@zai/glm-5.1",  messages: [{ role: "user", content: "Explain vector cache routing." }],});console.log(completion.choices[0]?.message?.content);

Endpoint

Base URL

https://api.z.ai/api/paas/v4

Chat completions

https://api.z.ai/api/paas/v4/chat/completions

Model

glm-5.1

Auth env

ZHIPU_API_KEY

GLM-5.1 FAQ

How much does the GLM-5.1 API cost?

Through Z.AI, GLM-5.1 costs $1.40 per 1M input tokens and $4.40 per 1M output tokens. The lowest input price in the catalog is $1.00 per 1M tokens on Hugging Face.

What is the context window of GLM-5.1?

GLM-5.1 accepts up to 200K tokens of context and returns up to 131.1K output tokens on Z.AI.

Which providers offer GLM-5.1?

GLM-5.1 is available from Hugging Face, Fireworks AI, Together AI and Z.AI. Everstack can route between them with automatic fallback when one is unavailable.

What can GLM-5.1 do?

GLM-5.1 supports chat, function calling and reasoning. It accepts text input.

How do I call GLM-5.1 through Everstack?

Point any OpenAI-compatible SDK at your Everstack gateway and set the model to @zai/glm-5.1. Everstack adds retries, provider fallback, caching, per-tenant budgets and OpenTelemetry traces for every request.