Anthropic
anthropic.com › claude › sonnet
Claude Sonnet 4.5
September 29, 2025 - Pricing for Sonnet 4.5 starts at $3 per million input tokens and $15 per million output tokens, with up to 90% cost savings with prompt caching and 50% cost savings with batch processing. To learn more, check out our pricing page. To get started, simply use claude-sonnet-4-5 via the Claude API.
Anthropic
anthropic.com › news › claude-sonnet-4-5
Introducing Claude Sonnet 4.5
September 29, 2025 - Claude Sonnet 4.5 is available everywhere today. If you’re a developer, simply use claude-sonnet-4-5 via the Claude API.
Bring your Own Key to access Claude Sonnet 4 & Opus 4 Models
What am I paying the subscription fee for then? More on reddit.com
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May 23, 2025How do I get access to Claude 4 Sonnet API tokens?
I just made an account yesterday and have been using Claude 3 haiku. But I want to use Claude 3 sonnet. But I see they released Claude 4 sonnet? How… More on reddit.com
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April 24, 2025Anyone else notice Claude Sonnet 4.5 writing way too much lately? Here’s how I fixed it.
Yesterday I had it research an implementation in my code base to then implement an enhancement. When it was done exploring, it wrote a huge “research summary” document and then a huge “implementation plan” document. I didn’t like the plan it came up with so it wrote a totally separate “updated plan” document. Then when it was done it wrote an “implementation summary” document and a “user guide” document. It’s insane. I even added a Claude Rule similar to yours saying not to write documents like these unless absolutely needed and helpful. Such a waste of tokens. More on reddit.com
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November 10, 2025[BUG] Sonnet 4.5 not found in Claude Code
There was an error while loading. Please reload this page · I get this error when trying to use Claude Code - Sonnet 4.5 More on github.com
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Videos
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Claude Code with Sonnet 4.5 is actually incredible (with 1 exception) ...
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How I Got GPT-5 & Claude 4.5 Access for $0 — 40M Tokens + $200 ...
09:26
Claude Sonnet 4.5 is HERE + Claude Code Upgrades - YouTube
06:54
How To Use Unlimited GPT-5 & Sonnet 4.5 For Free in 2025.. - YouTube
r/ClaudeAI on Reddit: Introducing Claude Haiku 4.5: our latest ...
Claude
docs.claude.com › en › docs › get-started
Get started with Claude - Claude Docs
curl https://api.anthropic.com/v1/messages \ -H "Content-Type: application/json" \ -H "x-api-key: $ANTHROPIC_API_KEY" \ -H "anthropic-version: 2023-06-01" \ -d '{ "model": "claude-sonnet-4-5", "max_tokens": 1000, "messages": [ { "role": "user", "content": "What should I search for to find the latest developments in renewable energy?"
OpenRouter
openrouter.ai › anthropic › claude-sonnet-4.5
Claude Sonnet 4.5 - API, Providers, Stats | OpenRouter
September 29, 2025 - Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. Run Claude Sonnet 4.5 with API
Apidog
apidog.com › blog › claude-sonnet-4-5-api
How to Use the Claude Sonnet 4.5 API
September 30, 2025 - Anthropic makes the Claude Sonnet ... an account on the Anthropic Console. Once registered, they navigate to the Account Settings section to generate an API key....
Reddit
reddit.com › r/windsurf › bring your own key to access claude sonnet 4 & opus 4 models
r/windsurf on Reddit: Bring your Own Key to access Claude Sonnet 4 & Opus 4 Models
May 23, 2025 -
BYOK (Anthropic Key) Support Added!
You can now bring your own Anthropic API key to access Claude 4 models in Cascade:
- Claude Sonnet 4 & Claude Sonnet 4 (Thinking)
- Claude Opus 4 & Claude Opus 4 (Thinking)
To enable: Go to "provide API keys" → input your Anthropic key → reload Windsurf window.
Available now for Free and Pro users!
See full changelog: https://windsurf.com/changelog
Reddit
reddit.com › r/claudeai › how do i get access to claude 4 sonnet api tokens?
r/ClaudeAI on Reddit: How do I get access to Claude 4 Sonnet API tokens?
April 24, 2025 - Claude Coded: Sonnet 4.5, Claude Code 2.0, and more.
Reddit
reddit.com › r/anthropic › anyone else notice claude sonnet 4.5 writing way too much lately? here’s how i fixed it.
r/Anthropic on Reddit: Anyone else notice Claude Sonnet 4.5 writing way too much lately? Here’s how I fixed it.
November 10, 2025 -
Lately, Claude Sonnet 4.5 kept generating tons of stuff I didn’t ask for (extra docs, summaries, JSON plans, etc.) It looked smart but was actually useless i did not need it and on top of that it burned through my credits fast.
What fixed it: I went to Settings then General then “What personal preferences should Claude consider in responses?” and added a short note asking for concise answers, only what I request.
"Keep responses concise and focused. Provide only what I explicitly request."
"Avoid generating extra documents, summaries, or plans unless I specifically ask for them."
Now it’s back to normal, focused, shorter, and way cheaper in tokens. Curious if others saw the same overproduction issue or if it was just me?
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Yesterday I had it research an implementation in my code base to then implement an enhancement. When it was done exploring, it wrote a huge “research summary” document and then a huge “implementation plan” document. I didn’t like the plan it came up with so it wrote a totally separate “updated plan” document. Then when it was done it wrote an “implementation summary” document and a “user guide” document. It’s insane. I even added a Claude Rule similar to yours saying not to write documents like these unless absolutely needed and helpful. Such a waste of tokens.
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It's same for me. Writing so much useless stuff and wasting my time. Thanks for your prompts. I will test
Claude
claude.com › platform › api
Claude Developer Platform | Claude
“We're seeing state-of-the-art coding performance from Claude Sonnet 4.5, with significant improvements on longer horizon tasks.
GitHub
github.com › RooCodeInc › Roo-Code › issues › 8386
[BUG] Sonnet 4.5 not found in Claude Code · Issue #8386 · RooCodeInc/Roo-Code
September 29, 2025 - I get this error when trying to use Claude Code - Sonnet 4.5 · API Request Failed {"type":"error","error":{"type":"not_found_error","message":"model: claude-4.5-sonnet"},... Happens when user tries to use Claude Code as provider and Sonnet 4.5 as the model. Set provider to Claude Code, select Sonnet 4.5 as the model.
Published Sep 29, 2025
Claude
claude.ai
Claude
Talk with Claude, an AI assistant from Anthropic
ClaudeLog
claudelog.com › home › troubleshooting
ClaudeLog - Claude Code Docs, Guides, Tutorials & Best Practices
November 11, 2025 - Use correct syntax: claude --model claude-sonnet-4-5-20250929 · Check subscription - Ensure access to requested model · Restart session after model change · Verify model names - Use exact model identifiers · Update Claude Code - Newer versions support more models ·
Claude Docs
platform.claude.com › docs › en › about-claude › models › overview
Models overview - Claude Docs
Once you've picked a model, learn how to make your first API call. 1 - Aliases automatically point to the most recent model snapshot. When we release new model snapshots, we migrate aliases to point to the newest version of a model, typically within a week of the new release. While aliases are useful for experimentation, we recommend using specific model versions (e.g., claude-sonnet-4-5-20250929) in production applications to ensure consistent behavior.
AWS
aws.amazon.com › blogs › aws › introducing-claude-sonnet-4-5-in-amazon-bedrock-anthropics-most-intelligent-model-best-for-coding-and-complex-agents
Introducing Claude Sonnet 4.5 in Amazon Bedrock: Anthropic’s most intelligent model, best for coding and complex agents | Amazon Web Services
September 29, 2025 - Getting started To begin working with Claude Sonnet 4.5, you can access it through Amazon Bedrock using the correct model ID. A good practice is to use the Amazon Bedrock Converse API to write code once and seamlessly switch between different models, making it easier to experiment with Sonnet 4.5 or any of the other models available in Amazon Bedrock.
Claude Docs
platform.claude.com › docs › en › api › errors
Errors - Claude Docs
import anthropic client = anthropic.Anthropic() message = client.messages.create( model="claude-sonnet-4-5", max_tokens=1024, messages=[ {"role": "user", "content": "Hello, Claude"} ] ) print(f"Request ID: {message._request_id}") We highly encourage using the streaming Messages API or Message Batches API for long running requests, especially those over 10 minutes.
Cursor
forum.cursor.com › bug reports
Claude 4.5 Thinking model returning 404 errors in Cursor 2.0.69 - Page 2 - Bug Reports - Cursor - Community Forum
November 12, 2025 - Where does the bug appear (feature/product)? Cursor IDE Describe the Bug When using my own Anthropic API key, requests to sonnet 4.5 Thinking model fails with a 404 error. Other Claude models (like 3.5 Sonnet and Haiku)…
Shuttle
shuttle.dev › blog › 2025 › 10 › 01 › build-rust-api-sonnet-4-5
Building a Rust API with Claude Sonnet 4.5 | Shuttle
October 1, 2025 - To bring back their users, Anthropic is finally back with a new model Sonnet 4.5 and the Claude Code VSCode extension has also been updated, so you can use Sonnet 4.5 directly in VSCode or Cursor for a better experience. ... So let's see if Sonnet 4.5 is actually worth the hype and put it to the test, we as Rust developers like coding in Rust so this is what this blog post is about, we'll let Sonnet 4.5 build a Rust API for us that collects from 3 RSS feeds and serves them through an HTTP API.
Reddit
reddit.com › r/githubcopilot › claude sonnet 4.5 (preview) in github copilot is addicted to “comprehensive summary documents”
r/GithubCopilot on Reddit: Claude Sonnet 4.5 (preview) in GitHub Copilot is addicted to “comprehensive summary documents”
October 3, 2025 -
Been trying out the new Claude Sonnet 4.5 coding agent in GitHub Copilot. Honestly? It’s incredibly good fast at coding, nails fixes, feels like cheating sometimes.
But it has this one hilarious quirk: every tiny request, even a one-line bug fix, and it’s like, “Sure, here’s your code... oh, and also a comprehensive summary document in Markdown.” and this happens several times in one session so the .md files keep piling up quick.
So you end up with perfect code and a project report you never asked for. Not a dealbreaker, just funny that "best coding model in the world" also moonlights as your unsolicited technical writer.
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I am using this feature HEAVILY to my advantage and it literally transforms Sonnet into the best three senior developers that I've ever had working for me. I promise that if you try this approach, you will never look back: Get Sonnet to create a PHASED "feature planning" document for a single WELL-DEFINED ticket (I've got it to talk to Jira via powershell. If you're using git issues, it has native access to those), to include a section on progress and another on questions for clarification. The resultant file goes into a .gitignored folder and is named in line with the ticket number. I've updated the .github/copilot-instructions.md to understand all this. Next, open N x Visual Studios (for me N is 3, maybe start with 1!) and each on a different worktree. If you're not familiar with worktrees, they let you use one local repo, but with different folders on different branches. Now rotate amongst them. This is HIGHLY efficient. Yes it churns tokens. Yes it's worth it! When each planning document has no more clarifying questions, let it set about each phase with copilot-instructions. I get it to use me to validate completeness of the phase before proceeding to the next. I use regular staging / commits to carefully manage its progress and have no qualms about ditching changes in git, resetting the conversation and just say "we're working on XY-12345. . Update the plans and continue". Because the plan/progress document is being kept up to date, you can interrupt progress, suffer IDE crashes without impact etc. Finally, once the feature is complete, have it: Attach the .md to the ticket Write a test plan Pass the ticket to Q/A Clean up after itself. Side note. Use Windows H to work at the speed of thought, but also to permit you to stop and think without having a ChatGPT-like experience of the AI hating silence and talking to fill the gaps. Suggestion: Create a ticket in your ticketing system with a hyperlink to this comment and ask it to PLAN how you and they can work together better in future. Tl;Dr: Documentation is good, and embracing that will make you a better software engineer.
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After the "You are absolutely right!" fiasco looks like we now have "Perfect! Let me create a document...".