claude-sonnet-4-6
Capability: 200K context · tool use · vision · prompt caching · streaming
Pricing: per-token, Sonnet tier (live rate)
Sonnet 4.6 is what you should reach for first inside the 4-series. It
keeps the 200K context window and tool-use shape of 4.5, while
delivering measurably better structured output and tighter tool-call
arguments. If you’re starting a new project, default here. If you’re on
4.5, the migration is a single string change — most production code
sees a quality bump with no measurable latency or cost difference.
Request
Body parameters
Response
Code examples
Streaming
Set"stream": true for SSE in the standard Anthropic format. Estimated
credits ship in the HTTP headers before the first event.
Cache control
cache_control blocks reduce cost on repeated prompts. Cache reads at
the discounted rate visible in the
pricing table. With Sonnet 4.6’s
tighter tool-arg generation, retrieval-augmented agent loops see the
biggest cache wins (system prompt + tool schema kept stable, only the
user turn changes).
Errors
When to use
- Default Anthropic mid-tier — start here, benchmark against Opus / Haiku later.
- Code generation / refactoring / structured extraction where Haiku is too imprecise.
- Tool-heavy agents where parallel tool calls and tight argument JSON matter.
- For higher throughput at lower quality, see Haiku 4.5.
- For deeper reasoning across long contexts, see Opus 4.7.