Claude Sonnet 5
claude-sonnet-5Sonnet 5 is Anthropic's most capable Sonnet-class model, delivering frontier-level performance across coding, agentic workflows, and professional knowledge tasks. It supports text, image, and file inputs, features a 1M-token context window, and offers adaptive thinking with configurable reasoning levels (low, medium, high, max, and x-high) to balance speed, cost, and reasoning depth. Optimized for complex coding, long-horizon agent execution, and professional workflows, Sonnet 5 combines strong reasoning, robust instruction following, and enhanced safety features, including an updated tokenizer and real-time cyber safeguards for high-risk dual-use scenarios.
- Context
- 1M tokens
- Endpoint
Pricing
Quick Start
Select an endpoint and copy a working example for this model.
from openai import OpenAI client = OpenAI( api_key="YOUR_API_KEY", base_url="https://api.apertis.ai/v1") response = client.chat.completions.create( model="claude-sonnet-5", messages=[ {"role": "user", "content": "Hello!"} ], max_tokens=1024, temperature=0.7) print(response.choices[0].message.content) # Optional: Enable context compression to reduce token usage# response = client.chat.completions.create(# model="claude-sonnet-5",# messages=[{"role": "user", "content": "Hello!"}],# extra_body={"compression": {"enabled": True, "model": "gpt-4.1-mini"}}# )Supported Parameters
API docsmodelmessagesmax_tokenstemperaturetop_pstreamtoolsreasoning_effortstream_optionsthinkingextra_bodyCursor IDE Model IDs
Use these namespaced identifiers in Cursor IDE to avoid conflicts with built-in models.
Compare with Other Models
See how this model compares to others from the same provider.
Claude Fable 5.1
Claude Fable 5.1 is an upgraded version of Fable 5, delivering broad improvements with particularly strong gains in agentic coding, long-running workflows, and professional knowledge work. It excels at large code refactors, front-end and visual code generation, financial analysis, and complex analytical tasks. Compared with Fable 5, it also produces more concise plans and summaries while maintaining strong performance across extended tasks, making it a natural upgrade for existing Fable workflows and a strong option alongside Opus 5 for reasoning-intensive applications.
- Context
- 1M
- Input
- $10.00/M
- Output
- $50.00/M
Claude Sonnet 4.5 (Thinking)
Claude Sonnet 4.5 is Anthropic's most advanced Sonnet model, built for real-world agents and coding workflows. It delivers top-tier coding performance (including SWE-bench Verified) with stronger system design, security, and spec adherence, and supports long-running autonomous work with progress tracking. It introduces more powerful agent features — better tool orchestration, speculative parallel execution, and smarter context/memory management — making it especially effective for complex, multi-context workflows across engineering, security, finance, and research.
- Context
- 1M
- Input
- $1.50/M
- Output
- $7.50/M
Claude Haiku 4.5 (Thinking)
Claude Haiku 4.5 is Anthropic's fastest, most efficient model, offering near-frontier capability at much lower cost and latency. It now supports extended, controllable reasoning and full tool-assisted workflows, including coding and computer use. With >73% on SWE-bench Verified, it matches Sonnet-level performance while staying highly responsive for real-time and large-scale deployments.
- Context
- 200K
- Input
- $0.50/M
- Output
- $2.50/M
Claude Sonnet 4
Claude Sonnet 4 is a major upgrade over Sonnet 3.7, delivering stronger coding and reasoning with better precision and control. It reaches 72.7% on SWE-bench, while staying efficient and responsive, making it useful for everything from everyday coding to complex software projects. Improvements include better autonomous codebase navigation, fewer agent workflow errors, and more reliable handling of complex instructions.
- Context
- 200K
- Input
- $1.00/M
- Output
- $5.00/M