OpenRouter: Claude Sonnet 4

Name: Claude Sonnet 4 API
Brand: Anthropic

stable

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

anthropic-claude-sonnet-4claudereleased May 22, 2025

Provider Quick start

Context

tokens

Max output

64K

tokens

Input

$3.00

per 1M

Output

$15.00

per 1M

Activity

Daily period usage

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

Providers

ProviderContextInput /MOutput /M

OpenRouter

1M$3.00$15.00

Pricing

Item	Price	Unit
Input	$3.00	per 1M tokens
Output	$15.00	per 1M tokens
Cache read	$0.30	per 1M tokens
Cache write	$3.75	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: anthropic-claude-sonnet-4
Family: claude
Status: stable
Knowledge: -
Released: May 22, 2025

Gateway Config

API: 2024-01-01
Auth: OPENROUTER_API_KEY
Discovery: dynamic
Provider type: meta

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: "@openrouter/anthropic-claude-sonnet-4",  messages: [{ role: "user", content: "Explain vector cache routing." }],});console.log(completion.choices[0]?.message?.content);

Endpoint

Base URL

https://openrouter.ai/api/v1

Chat completions

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

Model

anthropic-claude-sonnet-4

Auth env

OPENROUTER_API_KEY

Claude Sonnet 4 FAQ

How much does the Claude Sonnet 4 API cost?

Through OpenRouter, Claude Sonnet 4 costs $3.00 per 1M input tokens and $15.00 per 1M output tokens.

What is the context window of Claude Sonnet 4?

Claude Sonnet 4 accepts up to 1M tokens of context and returns up to 64K output tokens on OpenRouter.

What can Claude Sonnet 4 do?

Claude Sonnet 4 supports chat, function calling, image input and reasoning. It accepts image, text and PDF input.

How do I call Claude Sonnet 4 through Everstack?

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