> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bettertoken.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Claude Sonnet 5.5 is now available on BetterToken

> Claude Sonnet 5.5 is available on BetterToken as claude-sonnet-5-5 for focused coding, bug fixes, professional documents, presentations, and spreadsheets.

Release date: September 28, 2026

Claude Sonnet 5.5 is the second model in Anthropic's Claude 5.5 family. Anthropic positions it as a faster option for well-scoped everyday work, including coding, bug fixes, and polished documents, slides, and spreadsheets. For more open-ended, complex work, consider Opus 5.5.

**Claude Sonnet 5.5** is now available on BetterToken. Set the Base URL to `https://bettertoken.ai`, and use `claude-sonnet-5-5` as the model ID. Check the <a href={"https://bettertoken.ai/pricing"}>model plaza</a> for current availability and pricing.

## Highlights

* **Focused coding**: use it for well-defined implementation tasks and bug fixes.
* **Professional output**: Anthropic highlights its work on documents, slides, and spreadsheets.
* **Long context**: Anthropic lists a 1M-token context window and up to 128K output tokens.

## Before switching from Sonnet 5

If your client calls the Anthropic Messages API directly, review the [official migration guide](https://platform.claude.com/docs/en/models/sonnet-5-5/migration-guide) before changing the model ID. Sonnet 5.5 changes some thinking and tool-choice behavior; test representative requests first.

## Connect it

1. <a href={"https://bettertoken.ai/register"}>Create a BetterToken API Key</a>.
2. Use `https://bettertoken.ai` as the Base URL.
3. Set the model ID to `claude-sonnet-5-5`.
4. Test a representative task before moving production traffic.

Use the [Claude Code setup guide](/en/ai-tools/claude-code) for client setup, or compare alternatives in the [model selection guide](/en/faq/model-calling/model-selection-guide).

## Official sources

* [Introducing Claude Sonnet 5.5](https://www.anthropic.com/claude-sonnet-5-5)
* [Claude Sonnet 5.5 model overview](https://platform.claude.com/docs/en/models/sonnet-5-5/overview)


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