Hey everyone! Claude Sonnet 4.5 just went live in Cline.

Same pricing as Sonnet 4 ($3/$15), 200k or 1M context window, but the behavior is noticeably different. The model is way more terse -- it skips the narration and just executes. Where Sonnet 4 would explain every step, 4.5 chains operations together and only speaks up when it needs clarification.

The big improvement is how it handles long tasks. It naturally maintains state files (progress.txt, implementation notes, test manifests) and picks up exactly where it left off across sessions.

This pairs well with Cline's Auto Compact and Focus Chain features. When context gets compressed, the model's state files provide additional continuity.

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

Full details: https://cline.bot/blog/claude-sonnet-4-5

Curious what the community thinks of the latest iteration of Claude Sonnet!

-Nick

It’s actually 2X-20X cheaper than Claude-3.7 when you measure on a full per message basis for many use-cases. The token cost only tells a small part of the story here, but in reality it’s the full interaction cost that matters.

A typical final message length is about 300 tokens, but Claudes reasoning can be upto 64K tokens, and you have to pay for all of that… Using 64K tokens of reasoning along with a final message of 300 tokens would result in a claude api cost of about 90 cents for that single message.

Meanwhile, GPT-4.5 only costs 4 cents for that same 300 token length message… That’s literally 20X cheaper cost per message than Claude in this scenario.

But ofcourse you’re not always maxing out claudes reasoning limit, but even if you only use 10% of Claude-3.7s reasoning limit, you will still end up with a cost of still about 10 cents per message, and that’s still more than 2X what GPT-4.5 would cost.

This is not some fringe scenario I’m talking about here either, 10% reasoning usage is not at all abnormal, but lets say even if Claude-3.5-sonnet only used 5% of it’s reasoning capacity, that still would only bring it to equal cost of GPT-4.5 and not cheaper.

Guys.

It is so expensive.

Please.

Make it cheaper...