Claude Sonnet 4.6
Claude Sonnet 4.6 brings Opus-approaching intelligence to the Sonnet tier with adaptive thinking, a context window of 1M tokens, strong agentic coding, frontend UI quality, and computer use accuracy improvements, plus MCP support for scaled tool use and interleaved thinking with tool calls.
import { streamText } from 'ai'
const result = streamText({ model: 'anthropic/claude-sonnet-4.6', prompt: 'Why is the sky blue?'})Playground
Try out Claude Sonnet 4.6 by Anthropic. Usage is billed to your team at API rates. Free users (those who haven't made a payment) get $5 of credits every 30 days.
Providers
Route requests across multiple providers. Copy a provider slug to set your preference. Visit the docs for more info. Using a provider means you agree to their terms, listed under Legal.
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P50 throughput on live AI Gateway traffic, in tokens per second (TPS). Visit the docs for more info.
P50 time to first token (TTFT) on live AI Gateway traffic, in milliseconds. View the docs for more info.
Direct request success rate on AI Gateway and per-provider. Visit the docs for more info.
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About Claude Sonnet 4.6
Claude Sonnet 4.6 launched on AI Gateway on February 17, 2026. Anthropic described it as approaching Opus-level intelligence. The model advances multiple capabilities the Sonnet tier developed across the 4.x generation: stronger agentic coding, improved code review, better frontend UI quality, and higher computer use accuracy.
Two architecture features define Sonnet 4.6. First, adaptive thinking: the model decides when and how much to reason, rather than requiring a fixed extended thinking budget. Simpler requests get a proportionate response. Complex ones receive deeper reasoning automatically. You don't need to categorize each request in advance. This evolves the thinking mode introduced in Claude 3.7 Sonnet into a smarter, model-directed form.
Second, a 1M-token context window at Sonnet pricing. Claude Sonnet 4.5 was the first Sonnet-tier model to reach 1M tokens; Sonnet 4.6 keeps that as standard. For teams working with large codebases, long document collections, or extended agent histories, Opus-approaching quality at 1M tokens and Sonnet pricing changes what's economically feasible.
MCP (Model Context Protocol) support for scaled tool use means Sonnet 4.6 can participate in large tool ecosystems without specifying individual tools for each interaction. The model proactively executes tasks, delegates to subagents, and parallelizes tool calls.
What To Consider When Choosing a Provider
- Configuration: Adaptive thinking calibrates token usage automatically. Pair it with the
effortparameter to manage cost on mixed workloads where some requests benefit from deep reasoning and others don't. - Zero Data Retention: AI Gateway supports Zero Data Retention for this model via direct gateway requests (BYOK is not included). To configure this, check the documentation.
- Authentication: AI Gateway authenticates requests using an API key or OIDC token. You do not need to manage provider credentials directly.
When to Use Claude Sonnet 4.6
Best For
- Agentic coding and code review: Requiring strong intelligence with efficient reasoning, the primary capability improvements in this release
- Frontend UI development: Quality of visual output matters, highlighted as an area of improvement over previous Sonnet versions
- Computer use workflows: Higher accuracy on GUI automation and screen-driven agents ships as a 4.6 improvement, at Sonnet pricing rather than the Opus tier
- Large-context agentic tasks: The context window of 1M tokens enables processing entire codebases or document sets at Sonnet pricing
- MCP-based tool environments: The model needs to interact with large, diverse tool ecosystems
Consider Alternatives When
- Maximum intelligence ceiling: Claude Opus 4.6 provides full Opus depth with the same 1M context window
- Tight latency budgets: Haiku 4.5 is faster and cheaper for well-bounded high-throughput requests
- Explicit thinking budgets: Earlier models like Claude 3.7 Sonnet accept a fixed
thinkingtoken budget instead of adaptive mode
Conclusion
Claude Sonnet 4.6 combines context of 1M tokens, adaptive thinking, MCP (Model Context Protocol) support, and Opus-approaching intelligence at Sonnet pricing. It's a strong default for agentic coding, large-context analysis, and frontend development.
Frequently Asked Questions
How does adaptive thinking differ from the fixed thinking budgets in earlier models?
The model decides when and how much to reason based on the request, rather than applying a developer-specified token budget. For mixed workloads with varying complexity, this avoids over-spending thinking tokens on simple requests while still applying deep reasoning to hard ones.
Does Claude Sonnet 4.6 have the context window of 1M tokens?
Yes. The context window of 1M tokens is part of Sonnet 4.6's standard specification.
What does MCP support mean for tool use in Sonnet 4.6?
MCP (Model Context Protocol) support lets the model interact with larger, standardized tool ecosystems without requiring individual tool specification per interaction. The model can proactively execute tasks, delegate to subagents, and parallelize tool calls.
Can Sonnet 4.6 interleave thinking and tool calls?
Yes. Sonnet 4.6 can interleave thinking and tool calls within a single response, reasoning about a problem, calling a tool, reasoning about the result, and calling another tool, all in one turn.
How do I configure adaptive thinking and effort for Sonnet 4.6 in the AI SDK?
Set the model to
anthropic/claude-sonnet-4.6. UnderproviderOptions.anthropic, pass aneffortlevel (for example,medium) andthinking.typeset toadaptive.What does "Opus-approaching intelligence" mean practically for my use cases?
Sonnet 4.6 narrows the gap between the Sonnet and Opus tiers. For tasks where Opus previously justified its higher cost, benchmark Sonnet 4.6 as a potentially equivalent alternative at lower per-token pricing.
What were the specific capability improvements in Sonnet 4.6 over previous Sonnet models?
Agentic coding, code review, frontend UI generation, and higher-fidelity instruction following all improved. The model approaches Opus-level intelligence while maintaining Sonnet-tier cost and latency.