Claude Opus 5.5 is Anthropic's flagship model for demanding reasoning, coding, and long-horizon agentic work, succeeding Claude Opus 5. Particularly strong at multi-step changes in large codebases and code review. Multimodal input (text, image, file), 1M-token context, extended thinking, tools and structured outputs.
Claude Opus 5.5 is Anthropic's flagship model, succeeding Claude Opus 5, for demanding reasoning, coding and long-horizon agentic work. It is particularly strong at multi-step changes in large…
Multimodal input (text, images and files) with text output, a 1M-token context window and up to 128K output tokens. Supports extended thinking with configurable reasoning effort, function calling / tools, structured (JSON) outputs, temperature / stop controls and a verbosity setting. The model is moderated by the provider.
Input is billed at $4 per million tokens and output at $20 per million (USD). Prompt caching is available: cached input reads are billed at a steep discount to fresh input, with separate cache-write rates (including a 1-hour cache option). See the pricing on this page for the current numbers.
Call it through the Anthropic Messages API (POST /v1/messages) or the OpenAI-compatible Chat Completions API (POST /v1/chat/completions) with model anthropic/claude-opus-5.5 and your OrcaRouter API key — any Anthropic or OpenAI SDK works by setting the base URL to OrcaRouter. Supports tools / function calling, response_format for structured outputs, and reasoning_effort to tune depth.
OpenAI-compatible — keep the SDK you already use
https://api.orcarouter.ai/v1https://api.orcarouter.aiimport os
from openai import OpenAI
client = OpenAI(
base_url="https://api.orcarouter.ai/v1",
api_key=os.environ["ORCAROUTER_API_KEY"],
)
response = client.chat.completions.create(
model="anthropic/claude-opus-5.5",
messages=[{"role": "user", "content": "Hello"}],
)
print(response.choices[0].message.content)include_reasoningmax_completion_tokensmax_tokensreasoningreasoning_effortresponse_formatstopstructured_outputstemperaturetool_choicetoolsverbosity| Input / 1M tokens | $4.00 |
|---|---|
| Output / 1M tokens | $20.00 |
| Cache read / 1M | $0.200 |
| Cache write / 1M | $5.00 |
| Currency | USD |
Estimate based on list price
Estimate only — actual token counts depend on the provider's tokenizer.
What developers are saying this week
GET /api/public/models/anthropic/claude-opus-5.5Open @misc{orcarouter_claude_opus_5_5,
title = {Claude Opus 5.5 API},
author = {Anthropic},
year = {2026},
howpublished = {OrcaRouter},
url = {https://www.orcarouter.ai/models/anthropic/claude-opus-5.5}
}Anthropic. (2026). Claude Opus 5.5 API. OrcaRouter. https://www.orcarouter.ai/models/anthropic/claude-opus-5.5