What is Anthropic: Claude Opus 5.5's context window?

Anthropic: Claude Opus 5.5 supports a context window of 1,000,000 tokens, allowing you to process large documents and maintain long conversations.

How to use Anthropic: Claude Opus 5.5 API via Ofox?

Simply set your base URL to https://api.ofox.run/v1 and use your Ofox API key. The API is OpenAI-compatible — just change the base URL and API key in your existing code.

Anthropic: Claude Opus 5.5

Name: Anthropic: Claude Opus 5.5
Brand: anthropic
Price: 4 USD
Availability: InStock

Chat

anthropic/claude-opus-5.5

Compare Try in Playground Get started

Claude Opus 5.5 is the successor to Claude Opus 5 in Anthropic's Opus line, for demanding reasoning, coding, and long-horizon agentic work. It supports text, image, and file inputs with text output, with always-on adaptive reasoning (effort is the only control), a 1M-token context window, and up to 128K output tokens, at a lower per-token price than Claude Opus 5.

Context Window

Max Output Tokens

128K

Released

2026-09-22

Capabilities

VisionFunction CallingReasoningPrompt CachingWeb SearchPDF Input

Available Providers

Bedrock

Supported Protocols

openaianthropic

Providers

Bedrockprovider.type: "aws_bedrock"

Input Tokens

$4/M

Output Tokens

$20/M

Cache Read

$0.2/M

Cache Write (5 min)

$5/M

Cache Write (1 hour)

$8/M

Web Search

$0.015/R

Protocols

openai/v1/chat/completions/v1/responses

anthropic

Playground

Open in OfoxChat

Code Examples

import anthropic

client = anthropic.Anthropic(
    base_url="https://api.ofox.run/anthropic",
    api_key="YOUR_OFOX_API_KEY",
)

message = client.messages.create(
    model="anthropic/claude-opus-5.5",
    max_tokens=1024,
    messages=[
        {"role": "user", "content": "Hello!"}
    ],
)

print(message.content[0].text)