Anthropic: Claude Sonnet 4.5
anthropic/claude-sonnet-4.5- Modalities
- text+image+file->text
- In / out price
- $3 / $15
- Context
- 1M
- Released
- Sep 29, 2025
- Knowledge cutoff
- 2025-01-31
per 1M
Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. It delivers state-of-the-art performance on coding benchmarks such as SWE-bench Verified, with...
Supported parameters
include_reasoningInclude reasoning
Include a reasoning summary in the response.
max_completion_tokensMax completion tokens
Same idea as max_tokens. Some newer models use this field instead.
max_tokensMax tokens
Upper bound on generated tokens. Output stops at the limit.
reasoningReasoning
Enable or configure reasoning. The fields differ by model.
response_formatResponse format
For example json_object or json_schema, to constrain the shape.
stopStop
Stop when these strings are produced. A string or an array of strings.
structured_outputsStructured outputs
Generate a parseable structure that follows a JSON Schema.
temperatureTemperature
Sampling temperature. Lower is steadier, higher is more varied. Often 0 to 2.Default 1
tool_choiceTool choice
Whether to call a tool: auto, none, or a named function.
toolsTools
Function definitions the model may call via tool_calls.
top_kTop-K
Sample only from the K most likely tokens.
top_pTop-p
Sample only from tokens whose cumulative probability reaches top_p.Default 1