xAI: Grok 4 Fast

Name: Grok 4 Fast API
Brand: Xai

stable

Grok 4 Fast is available through Everstack's OpenAI-compatible gateway with routing, fallback, retries, and observability.

grok-4-fastgrok

Provider Quick start

Context

tokens

Max output

30K

tokens

Input

$0.20

per 1M

Output

$0.50

per 1M

Activity

Daily period usage

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

Providers

ProviderContextInput /MOutput /M

xAI

2M$0.20$0.50

Pricing

Item	Price	Unit
Input	$0.20	per 1M tokens
Output	$0.50	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: grok-4-fast
Family: grok
Status: stable
Knowledge: -
Released: -

Gateway Config

API: 2024-01-01
Auth: XAI_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: "@xai/grok-4-fast",  messages: [{ role: "user", content: "Explain vector cache routing." }],});console.log(completion.choices[0]?.message?.content);

Endpoint

Base URL

https://api.x.ai/v1

Chat completions

https://api.x.ai/v1/chat/completions

Model

grok-4-fast

Auth env

XAI_API_KEY

Grok 4 Fast FAQ

How much does the Grok 4 Fast API cost?

Through xAI, Grok 4 Fast costs $0.20 per 1M input tokens and $0.50 per 1M output tokens.

What is the context window of Grok 4 Fast?

Grok 4 Fast accepts up to 2M tokens of context and returns up to 30K output tokens on xAI.

What can Grok 4 Fast do?

Grok 4 Fast supports chat, function calling, image input and reasoning. It accepts text and image input.

How do I call Grok 4 Fast through Everstack?

Point any OpenAI-compatible SDK at your Everstack gateway and set the model to @xai/grok-4-fast. Everstack adds retries, provider fallback, caching, per-tenant budgets and OpenTelemetry traces for every request.