How much does prompt caching save on claude-sonnet-4-5-20250929?

claude-sonnet-4-5-20250929 supports prompt caching, which can significantly reduce costs for repeated prompts with shared prefixes. The cache read price is substantially lower than the standard input price. Check the current pricing page for the exact cache hit discount ratio for claude-sonnet-4-5-20250929.

What should you evaluate before moving production traffic to Claude Sonnet 4.5?

Test your software engineering, cybersecurity, and financial analysis workflows. Verify extended autonomous operation and tool orchestration for long-running tasks.

How do you get a cache hit on claude-sonnet-4-5-20250929?

To get a cache hit on claude-sonnet-4-5-20250929, send requests with identical prompt prefixes. The cache is keyed by the beginning of your prompt; as long as the prefix matches a previous request, subsequent calls benefit from the lower cached rate. Keep system messages and initial context consistent across calls for best results.

Does Claude Sonnet 4.5 support tool calling and structured output?

Yes. Sonnet 4.5 supports improved tool orchestration, speculative parallel execution, and efficient context and memory management. Test with your specific tool definitions.

Does claude-sonnet-4-5-20250929 have a free tier?

Claude Sonnet 4.5 is billed per use and the record publishes no free-tier allowance. The current published rates are input $3.0000 per 1M tokens and output $15.0000 per 1M tokens. Trial credit or promotional quota is tied to your account rather than to the model, so check the console before planning around a free tier.

How does claude-sonnet-4-5-20250929 compare with other models, and what should you compare?

Compare claude-sonnet-4-5-20250929 against models of similar capability and pricing on your actual workload. Evaluate latency, output quality, instruction following, and cost per task. Run side-by-side tests with your own prompts — the best model depends on your specific use case, not just benchmark scores.

Model detail

Claude Sonnet 4.5 20250929

Provided by Anthropic

Pay-as-you-go

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.

Model specs

Model ID: claude-sonnet-4-5-20250929

Context length: 200K
Max output: 64K
I/O modalities
Released: 2025-09

API endpoints

One MixRoute gateway, OpenAI-compatible

Anthropic Messages /v1/messages POST
OpenAI-compatible /v1/chat/completions POST
Gemini /v1beta/models/{model}:generateContent POST

Pricing

Flat rate, unit: /1M Tokens

Input

$3.0000 /1M Tokens

Completion

$15.0000 /1M Tokens

Cache read

$0.3000 /1M Tokens

Cache creation

$3.7500 /1M Tokens

Selection summary

Quickly judge whether it fits your workload

What is this model good for?

Real-world agents and coding with state-of-the-art performance

Use Claude Sonnet 4.5 for software engineering, cybersecurity, financial analysis, and research agents. It delivers state-of-the-art coding performance with improved tool orchestration and context management.

What should you check before using it?

Test extended autonomous operation and tool orchestration

Sonnet 4.5 supports extended autonomous operation with fact-based progress tracking. Test speculative parallel execution and context management for long-running workflows. Knowledge cutoff: 2025-01.

Why use it through MixRoute?

Claude Sonnet 4.5 keeps its 200,000-token context on one route

The full 200,000-token context stays reachable on the same route. MixRoute serves Claude Sonnet 4.5 on the OpenAI-compatible endpoint /v1/chat/completions; point your existing client at https://api.mixroute.ai/v1 with the model ID claude-sonnet-4-5-20250929 and re-run your integration tests.

Capabilities & compatibility

Unconfirmed capabilities stay "Unknown," no guesses

Tool calling

Claude Sonnet 4.5 supports function and tool calls.

EX Send a tools definition; the response returns tool_calls to execute and feed results back.

Structured output

Claude Sonnet 4.5 can produce JSON-formatted output on demand.

EX response_format: { type: "json_schema" } forces valid JSON output.

Streaming

Claude Sonnet 4.5 supports streamed responses.

EX stream: true streams tokens incrementally, so chat UIs render as they arrive.

Prompt caching

Claude Sonnet 4.5 supports prompt caching under supported routing conditions.

EX Keep the system prompt and tool definitions at the start of the request; repeated prefixes are automatically billed at the cache-read rate.

Vision input

Claude Sonnet 4.5 can process image inputs alongside text.

EX Pass a base64-encoded image in a image_url content part alongside text messages.

OpenAI SDK

Call Claude Sonnet 4.5 through MixRoute's OpenAI-compatible endpoint.

EX Change base_url to https://api.mixroute.ai/v1; everything else follows the OpenAI style.

Token cost estimator

Live estimate from this page's pricing, not an actual bill

Input tokens Max per request 200K

Output tokens Max per request 64K

Requests / month

Cache hit rate 0%

Share of the same prefix read repeatedly, up to 100%

FAQ

Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model, optimized for real-world agents and coding workflows. It delivers state-of-the-art performance on SWE-bench Verified with improved tool orchestration and context management.

Get started

01

Create an API key

Generate a key in the Console; one key calls every model.
02

Set the base URL

Fully OpenAI SDK-compatible; just swap the URL to connect.

https://api.mixroute.ai/v1
03

Specify the model ID

In the request's model field, enter:

claude-sonnet-4-5-20250929

Create an API key

New users get $5 in free credits

Test this model and alternate routes with the same request format

Start from a real workload, then let quality, total cost, and failure conditions decide whether to send production traffic.

Create an API key View integration docs