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Claude Sonnet 4.5

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 improvements across system design, code security, and specification adherence. The model is designed for extended autonomous operation, maintaining task continuity across sessions and providing fact-based progress tracking. Sonnet 4.5 also introduces stronger agentic capabilities, including improved tool orchestration, speculative parallel execution, and more efficient context and memory management. With enhanced context tracking and awareness of token usage across tool calls, it is particularly well-suited for multi-context and long-running workflows. Use cases span software engineering, cybersecurity, financial analysis, research agents, and other domains requiring sustained reasoning and tool use.

Input / output, from
$1.50 / $7.50 per 1M
Weekly tokens / requests
313.7K / 29
Context
1M tokens
Released
Sep 29, 2025
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Agent setup

Paste into Claude Code, Cursor, or Codex

Help me set up the Respan gateway: fetch and follow https://www.respan.ai/docs/agent-setup.md. Use model "anthropic/claude-sonnet-4-5".

Read docs

Providers

4 routes from 3 providers, cheapest first, priced per 1M tokens after gateway discounts.

ProviderInputOutput
OpenRouteropenrouter/anthropic/claude-sonnet-4.5:batch
$1.50/M$7.50/M
Anthropicanthropic/claude-sonnet-4-5
$3.00/M$15.00/M
OpenRouteropenrouter/anthropic/claude-sonnet-4.5
$3.00/M$15.00/M
Perplexityperplexity/anthropic/claude-sonnet-4-5
$3.00/M$15.00/M

Is a provider down? OpenRouter status, Anthropic status, Perplexity status

Pricing

Averaged across 4 routes from 3 providers, in USD per 1M tokens after gateway discounts.

Average input
$2.63 per 1M
Average output
$13.13 per 1M
Average cache read
$0.26 per 1M
Average cache write
$3.28 per 1M

Cost by volume

Total cost from 0 to 1T tokens on the cheapest and most expensive provider.

Highest$3.00/MAnthropic, OpenRouter, and PerplexityLowest$1.50/MOpenRouter

Throughput and latency

30-day averages from requests through the Respan gateway, 3 of 4 routes had traffic in that window. Under each figure, every model on the gateway by its average, this one in blue.

Output speed

Higher is better

31tokens/sbest, on OpenRouter

Faster than 17% of the other 485 models on the gateway
  • OpenRouter31 tok/s
  • Anthropic4.4 tok/s
  • Perplexity2.3 tok/s

Response latency

Lower is better

1.8sbest, on Anthropic

Faster than 0% of the other 501 models on the gateway
  • Anthropic1.8 s
  • Perplexity2.2 s
  • OpenRouter7.3 s

No traffic in the last 30 days on OpenRouter.

Benchmarks

The Respan Index plus 37 published scores from 11 sources, each linked to where it was published.

29.0/ 100

Respan Index#68 of 143

143 ranked models. The shaded band is this model's 95% interval, 25.8 to 32.6. Inkling and Claude Opus 4.1 fall inside it, so the gap is within the margin of error.
Claude Sonnet 4.5 by category: Coding 12.8, Agents 41.3, Reasoning 19.2, Knowledge & language 31.1, Human preference 50.1
  1. 68Claude Sonnet 4.529.0
  2. 67Inkling29.7
  3. 68Claude Opus 4.129.0

Published scores

BenchmarkScore
SWE-bench VerifiedAnthropic77.2%
SWE-bench VerifiedEpoch AI71.3%
Terminal-Bench 2.0Anthropic51%
WeirdMLHåvard Tveit Ihle47.7%
GSO Opt@1GSO12.7%
How the Respan Index works

How Claude compares: Claude vs Gemini, Claude vs Grok, Claude vs GPT

Apps

Use Claude Sonnet 4.5 in the tools you already run. Each guide points the app at the Respan gateway.

Setup guides for more apps are in the integration docs.

Claude Sonnet 4.5 FAQ

Short answers, built from the data on this page.

Certified where it counts.

Built to meet the security and privacy standards that enterprise and healthcare teams require.

ISO 27001

The internationally recognized standard for information security management.

SOC 2

Secure, compliant management of your data across all of our systems.

GDPR

Operated under GDPR, the world's strictest standard for data privacy.

HIPAA

HIPAA compliant, with a BAA available for healthcare teams.

Works with your entire stack

Use Respan with your favorite frameworks and tools.

AnthropicAI21 LabsxAIVercel AI SDK
LangChainOpenRouterAssemblyAICursor
LiteLLMGroqBasetenMem0
CohereCogneeLlamaIndexFireworks
DeepSeekLinkupHaystackTogether AI
PerplexityInference.netPostHogRubyLLM
SlackMastraAzure OpenAIMistral
AWS BedrockMoonshotHyperspellBAML
ModaInstructorGoogle GeminiParasail
ReductoZapierAgnoNebius
OpenAINovita AIReplicateSuperagent

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