Claude Opus 5.5 API

Anthropic Claude Opus 5.5: frontier model for agentic coding, long-horizon tasks and deep analysis. 1M context.

Anthropic·ChatAvailable

from$1.44/ 1M input tokens$1.610% off

Model IDclaude-opus-5.5

reasoningtoolscoding1m-context

Input

Text

Output

Chat

Provider

7 providers

Last 7 days · not enough recent requests for stats yet.

Claude Opus 5.5 pricing

Prices are per unit; requests without a provider are routed to the cheapest provider that supports your parameters.

OptionPrice (USD)
All options
$1.44 / 1M input tokens
144 Credits$1.610% off

Try Claude Opus 5.5 before you integrate

Test output quality, compare provider prices and estimate cost before writing any code.

Provider
Chat

Settings

PriceKIE AI
1M input tokens$1.44
1M output tokens$7.2

Credits for max_tokens are held first, then settled to the actual usage.

Claude Opus 5.5Auto (cheapest)
Claude Opus 5.5

Start a conversation. Replies stream in and are billed by actual token usage.

Enter to send · Shift + Enter for a new line

Claude Opus 5.5 prompt examples

Ready-to-use prompts. Load one into the playground and tweak it.

Source
Scene

5 prompts

Review this diff for correctness and security. List blocking issues with file and line, then any non-blocking suggestions. <paste diff here>

Interactive 3D scene

Creative coding

Build a single-file Three.js page showing a small volcanic island with animated water, a day/night slider and orbit controls.

Here is a screenshot of our revenue dashboard. Describe the three most important trends and anything that looks like a data error.

Claude Opus 5.5 API reference

Endpoints, request fields and runnable examples for this model.

Base URL

https://01router.com/api/v1
llms.txt

Quick start

Set API_KEY to your project key, then run a sample from your server. Replace example media URLs with your own public URLs.

Auto-routing chooses a provider that supports the request. Select a provider to see its input constraints and pinned request examples.

curl https://01router.com/api/v1/chat/completions \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-opus-5.5",
    "messages": [{ "role": "user", "content": "Hello!" }],
    "stream": false
  }'

Endpoints

Only endpoints relevant to this model are listed. Paths below include /api/v1. Click an endpoint to read its usage.

Authentication

Send your API key as a Bearer token. Requests are billed to the key owner's credits.

Authorization: Bearer YOUR_API_KEY
Content-Type: application/json
Get an API key

Input

Send messages directly in the request body. Chat requests do not use an input wrapper.

Request body

NameTypeRequiredDescription
modelstringYes"claude-opus-5.5"
providerstringNoPin a provider; omit to auto-route to the cheapest. One of: replicate | wavespeed | kie | apimart | evolink | vercel | openrouter
messagesobject[]YesOpenAI-format messages, each with role and content.
streambooleanNotrue returns an SSE stream.
max_tokensintegerNoOutput token cap; credits are pre-held for it (default 4096).

Output

This example uses stream: false. Read the reply from choices[0].message.content. With stream: true, read SSE chunks from choices[].delta until [DONE].

Task completed

{
  "id": "chatcmpl-example",
  "object": "chat.completion",
  "model": "claude-opus-5.5",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Hello! How can I help?"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 9,
    "completion_tokens": 8,
    "total_tokens": 17
  }
}

Response fields

NameTypeRequiredDescription
idstringYesChat completion ID
objectstringYeschat.completion
modelstringYesclaude-opus-5.5
choicesobject[]YesReply choices; message.content contains the non-streaming response.
usageobjectNoToken usage: prompt_tokens, completion_tokens and total_tokens. Availability depends on the provider.

Model schema

This public endpoint returns the model parameters and each provider’s supported constraints and prices.

curl "https://01router.com/api/v1/models/claude-opus-5.5"

Errors

Check the HTTP status and error.message. Fix the request before retrying validation or authentication errors. A failed generation is reported in status and error on the task itself.

{
  "error": {
    "message": "Invalid or missing API key",
    "code": "unauthorized"
  }
}

400Invalid body or parameter value

401Missing or invalid API key

402Not enough credits

404Unknown model or generation

429Too many requests — retry after the given seconds

502Every provider rejected the task (credits refunded)

Auth, routing, billing and error codes are covered in →

Use with AI

Give your coding assistant this model reference: endpoints, input constraints, output fields and request examples in plain text.

Open llms.txt

How does Claude Opus 5.5 compare?

Specs and starting prices side by side. Test with the same prompt before you choose.

Claude Opus 5.5Claude Sonnet 5.5GPT-6 AstraGPT-6 Sol
VendorAnthropicAnthropicOpenAIOpenAI
Starting price$1.44 / 1M input tokens$0.72 / 1M input tokens$2.52 / 1M input tokens$0.54 / 1M input tokens
InputTextTextTextText
Provider7 providers6 providers7 providers7 providers

Claude Opus 5.5 API FAQ

What is Claude Opus 5.5 best at?

Long-running agentic coding, knowledge work, reading charts and screenshots, and computer use. It is Anthropic's model for open-ended work that needs sustained judgment; Sonnet 5.5 covers everyday, high-volume work.

What are the context and output limits?

Up to 1M tokens of context and up to 128K output tokens. It accepts text and images and returns text, JSON and tool calls.

Can I turn thinking off?

Adaptive thinking is always on and controlled by the effort setting (low to max). Thinking tokens count toward max_tokens and are billed as output, so lower effort for simple requests.

Does it support tool calling and streaming?

Yes. Function calling and streaming are supported; forcing a specific tool choice may be rejected by some providers.

How is it billed on 01router?

Per 1M input and output tokens, settled from the provider's usage report. See the pricing table for each provider.

Related models

Other models you can call with the same API key.