Claude Opus 5.5

Claude Opus 5.5 is Anthropic's flagship Opus-tier model and the first release in the Claude 5.5 family, built for long-running agentic coding and knowledge work.

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input · usd / 1m tok

$4.00

output · usd / 1m tok

$20.00

context window

1mtokens

modalities · in → out

takes text and image in, gives text out

pricing

base api ratesusd per 1m tokens

input
$4.00
output
$20.00
cache read
$0.20
cache write · default ttl
$5.00
cache write · 1h ttl
$8.00

providers

Different companies host Claude Opus 5.5. Impossibl routes your request intelligently and handles failover automatically when a provider is down.

  • Azure AI Foundry
  • Anthropic

specifications

takes text and image in, gives text outanthropic/claude-opus-5-5

  • creatorAnthropic
  • model typeText generation
  • context window1,000,000 tokens
  • maximum outputnot published
  • input

    takes text and image in, gives text out

  • outputtext
  • tool callingnot verified
  • releasedsep 22, 2026
  • endpoint/v1/chat/completions

unknown means the public catalog does not establish that fact. a model's documented capabilities can differ from what a particular api supports. see the model documentation for integration details.

try it · your prompt, this model, live

# responses API
import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["IMPOSSIBL_API_KEY"],
    base_url="https://api.impossibl.com/v1",
)

resp = client.responses.create(
    model="anthropic/claude-opus-5-5",
    input="",
)
print(resp.output_text)

edit the prompt, then run

benchmarks

benchmark results are not available for this model yet.

compare Claude Opus 5.5 with other models

frontier labs and open weights, best-ranked firstusd / 1m tok · in / out

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frequently asked questions

What is Claude Opus 5.5?

Claude Opus 5.5 is Anthropic's flagship Opus-tier model and the first release in the Claude 5.5 family, built for long-running agentic coding and knowledge work. It succeeds Claude Opus 5 as the tier's default choice for multi-step changes across large codebases, code review, and financial and scientific analysis.

How much does Claude Opus 5.5 cost?

Claude Opus 5.5 costs $4.00 per million input tokens and $20.00 per million output tokens through the Impossibl API. Cache reads cost $0.20 per million tokens; cache writes cost $5.00 per million tokens; cache writes with one-hour retention cost $8.00 per million tokens. All rates are in USD.

view the pricing table ↑

What is the context length of Claude Opus 5.5?

Claude Opus 5.5 has a 1,000,000-token context window through the Impossibl API.

What inputs and outputs does Claude Opus 5.5 support?

Claude Opus 5.5 accepts text and image as input. Claude Opus 5.5 returns text.

How do I use Claude Opus 5.5 through an API?

Claude Opus 5.5 is available through the Impossibl API. Use anthropic/claude-opus-5-5 as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.

follow the api quickstart →

When was Claude Opus 5.5 released?

Anthropic released Claude Opus 5.5 on September 22, 2026.

this page describes Claude Opus 5.5 as listed by the impossibl public api. prices and availability come from that catalog, refreshed here every five minutes. this is an impossibl offering, not a comparison of independent hosting-provider quotes. model descriptions and release dates, where available, use the creator sources linked under the answers above.

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