Building LLM-Powered Applications with Claude

This skill helps you build LLM-powered applications with Claude. Choose the right surface based on your needs, detect the project language, then read the relevant language-specific documentation.

When to Use

• Use when building with the Claude API, Anthropic SDKs, or the Agent SDK.
• Use when code imports anthropic, @anthropic-ai/sdk, or related Claude SDK packages.
• Do not use for general coding work unrelated to Claude integrations.

Defaults

Unless the user requests otherwise:

For the Claude model version, please use Claude Opus 4.6, which you can access via the exact model string claude-opus-4-6. Please default to using adaptive thinking (thinking: {type: "adaptive"}) for anything remotely complicated. And finally, please default to streaming for any request that may involve long input, long output, or high max_tokens — it prevents hitting request timeouts. Use the SDK's .get_final_message() / .finalMessage() helper to get the complete response if you don't need to handle individual stream events

Language Detection

Before reading code examples, determine which language the user is working in:

1. Look at project files to infer the language:

2. *.py, requirements.txt, pyproject.toml, setup.py, Pipfile → Python — read from python/

3. *.ts, *.tsx, package.json, tsconfig.json → TypeScript — read from typescript/
4. *.js, *.jsx (no .ts files present) → TypeScript — JS uses the same SDK, read from typescript/
5. *.java, pom.xml, build.gradle → Java — read from java/
6. *.kt, *.kts, build.gradle.kts → Java — Kotlin uses the Java SDK, read from java/
7. *.scala, build.sbt → Java — Scala uses the Java SDK, read from java/
8. *.go, go.mod → Go — read from go/
9. *.rb, Gemfile → Ruby — read from ruby/
10. *.cs, *.csproj → C# — read from csharp/

11. *.php, composer.json → PHP — read from php/

12. If multiple languages detected (e.g., both Python and TypeScript files):

13. Check which language the user's current file or question relates to

14. If still ambiguous, ask: "I detected both Python and TypeScript files. Which language are you using for the Claude API integration?"

15. If language can't be inferred (empty project, no source files, or unsupported language):

16. Use AskUserQuestion with options: Python, TypeScript, Java, Go, Ruby, cURL/raw HTTP, C#, PHP

17. If AskUserQuestion is unavailable, default to Python examples and note: "Showing Python examples. Let me know if you need a different language."

18. If unsupported language detected (Rust, Swift, C++, Elixir, etc.):

19. Suggest cURL/raw HTTP examples from curl/ and note that community SDKs may exist

20. Offer to show Python or TypeScript examples as reference implementations

21. If user needs cURL/raw HTTP examples, read from curl/.

Language-Specific Feature Support

Which Surface Should I Use?

Start simple. Default to the simplest tier that meets your needs. Single API calls and workflows handle most use cases — only reach for agents when the task genuinely requires open-ended, model-driven exploration.