Anthropic

Claude Opus 4 API

Claude Opus 4 is Anthropic's most intelligent model — excelling at complex reasoning, multi-step agentic workflows, advanced coding, and nuanced long-form writing. It has a 200K token context window and supports vision. Use Opus when output quality matters more than cost.

Input
$15.00
/ 1M tokens
Output
$75.00
/ 1M tokens
Context
200K
tokens
Vision
Yes

Top use cases

  • Complex multi-step agents and tool use
  • Research-grade analysis and synthesis
  • Production-quality long-form writing
  • Advanced coding (architecture, refactoring, code review)
  • High-stakes decision support

Use Claude Opus 4 in 30 seconds

ModelServer is OpenAI-compatible. Point your existing OpenAI SDK at modelserver.dev/v1 and set the model name to claude-opus-4.

claude-opus-4.py
from openai import OpenAI

client = OpenAI(
    api_key="sk-modelserver-...",
    base_url="https://modelserver.dev/v1",
)

response = client.chat.completions.create(
    model="claude-opus-4",
    messages=[
        {"role": "user", "content": "Hello, Claude Opus 4!"}
    ],
)

print(response.choices[0].message.content)

Frequently asked questions

How much does Claude Opus 4 cost?
Claude Opus 4 is priced at $15.00 per 1M input tokens and $75.00 per 1M output tokens via ModelServer. ModelServer adds a flat 5.5% platform fee on top — no markups on individual tokens, no monthly minimum.
What is the Claude Opus 4 context window?
Claude Opus 4 supports a 200K token context window. You can put roughly 150,000 words in a single prompt.
Is Claude Opus 4 OpenAI-compatible via ModelServer?
Yes. Point your OpenAI SDK base_url to https://modelserver.dev/v1 and set model="claude-opus-4". Existing OpenAI-SDK code works without modification.
Who is Claude Opus 4 best for?
Teams that need the highest output quality and can pay flagship pricing.
Does Claude Opus 4 support vision input?
Yes. Claude Opus 4 accepts image inputs alongside text. Pass images as base64 or URL in the OpenAI-compatible message format.

Other Anthropic models

Claude Opus 4 API — Pricing & Access — ModelServer