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Claude Sonnet 5.5 API

NewLLM

Claude Sonnet 5.5 is Anthropic's newest Sonnet route: it keeps Sonnet 5's $2 / $10 rate card and 1M context, and adds always-on adaptive thinking to the balanced vision-and-tools mix.

Read the docsGet your API key
  • Input · USD / 1M tokens$0.56 USDOfficial price$2 USD
  • Output · USD / 1M tokens$2.8 USDOfficial price$10 USD
  • Savings72%
  • Context1M
  • Last verified2026-09-28
  • View tool pricing and billing rules

What are we making today?

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01

Where it fits

Claude Sonnet 5.5 is Anthropic's newest Sonnet route: it keeps Sonnet 5's $2 / $10 rate card and 1M context, and adds always-on adaptive thinking to the balanced vision-and-tools mix.

Choose Sonnet 5.5 for daily agent work that needs long context and tools, then replay your existing Sonnet 5 prompts before switching a working agent over.

02

Model capabilities

Vision

Accepts visual input alongside text for multimodal coding and analysis tasks.

Tool use

Can select and call tools in agent workflows that support structured tool use.

Adaptive thinking

Adjusts reasoning effort to the difficulty of the request.

03

OpenAI-compatible API

Keep your client and change the base URL, API key, and model ID.

curl
curl https://api.omniakey.com/v1/chat/completions \
  -H "Authorization: Bearer $OMNIAKEY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-5-5",
    "messages": [{"role": "user", "content": "Explain this codebase"}],
    "stream": true
  }'

04

Compatible coding tools

Claude Code
Cursor
Cline
Aider

More Anthropic models

Claude Opus 5

1M · claude-opus-5

Claude Opus 5.5

1M · claude-opus-5-5

Claude Haiku 5.5

1M · claude-haiku-5-5

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Frequently asked questions

How much does Claude Sonnet 5.5 cost on OmniaKey?

OmniaKey charges $0.56 USD per 1M input tokens and $2.8 USD per 1M output tokens, in USD. Official prices are $2 USD and $10 USD; you save 72%.

What is the context window for Claude Sonnet 5.5?

The listed context window is 1M. Actual usable limits can also depend on the client and upstream request format.

Which coding tools work with Claude Sonnet 5.5?

The current catalog lists compatibility with Claude Code, Cursor, Cline, Aider. Use the model ID shown on this page when the client supports model selection.