/claude-api

name: claude-api
description: "Build apps with the Claude API or Anthropic SDK. TRIGGER when: code imports `anthropic`/`@anthropic-ai/sdk`/`claude_agent_sdk`, or user asks to use Claude API, Anthropic SDKs, or Agent SDK. DO NOT TRIGGER when: code imports `openai`/other AI SDK, general programming, or ML/data-science tasks."
risk: unknown
source: "https://github.com/anthropics/skills"
date_added: "2026-03-21"
license: Complete terms in LICENSE.txt

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

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Language Detection

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

1. **Look at project files** to infer the language:

• `*.py`, `requirements.txt`, `pyproject.toml`, `setup.py`, `Pipfile` → **Python** — read from `python/`
• `*.ts`, `*.tsx`, `package.json`, `tsconfig.json` → **TypeScript** — read from `typescript/`
• `*.js`, `*.jsx` (no `.ts` files present) → **TypeScript** — JS uses the same SDK, read from `typescript/`
• `*.java`, `pom.xml`, `build.gradle` → **Java** — read from `java/`
• `*.kt`, `*.kts`, `build.gradle.kts` → **Java** — Kotlin uses the Java SDK, read from `java/`
• `*.scala`, `build.sbt` → **Java** — Scala uses the Java SDK, read from `java/`
• `*.go`, `go.mod` → **Go** — read from `go/`
• `*.rb`, `Gemfile` → **Ruby** — read from `ruby/`
• `*.cs`, `*.csproj` → **C#** — read from `csharp/`
• `*.php`, `composer.json` → **PHP** — read from `php/`

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

• Check which language the user's current file or question relates to
• If still ambiguous, ask: "I detected both Python and TypeScript files. Which language are you using for the Claude API integration?"

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

• Use AskUserQuestion with options: Python, TypeScript, Java, Go, Ruby, cURL/raw HTTP, C#, PHP
• If AskUserQuestion is unavailable, default to Python examples and note: "Showing Python examples. Let me know if you need a different language."

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

• Suggest cURL/raw HTTP examples from `curl/` and note that community SDKs may exist
• Offer to show Python or TypeScript examples as reference implementations

5. **If user needs cURL/raw HTTP examples**, read from `curl/`.

Language-Specific Feature Support

| Language | Tool Runner | Agent SDK | Notes | | ---------- | ----------- | --------- | ------------------------------------- | | Python | Yes (beta) | Yes | Full support — `@beta_tool` decorator | | TypeScript | Yes (beta) | Yes | Full support — `betaZodTool` + Zod | | Java | Yes (beta) | No | Beta tool use with annotated classes | | Go | Yes (beta) | No | `BetaToolRunner` in `toolrunner` pkg | | Ruby | Yes (beta) | No | `BaseTool` + `tool_runner` in beta | | cURL | N/A | N/A | Raw HTTP, no SDK features | | C# | No | No | Official SDK | | PHP | No | No | Official SDK |

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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.

| Use Case | Tier | Recommended Surface | Why | | ----------------------------------------------- | --------------- | ------------------------- | --------------------------------------- | | Classification, summarization, extraction, Q&A | Single LLM call | **Claude API** | One request, one response | | Batch processing or embeddings | Single LLM call | **Claude API** | Specialized endpoints | | Multi-step pipelines with code-controlled logic | Workflow | **Claude API + tool use** | You orchestrate the loop | | Custom agent with your own tools | Agent | **Claude API + tool use** | Maximum flexibility | | AI agent with file/web/terminal access | Agent | **Agent SDK** | Built-in tools, safety, and MCP support | | Agentic coding assistant | Agent | **Agent SDK** | Designed for this use case | | Want built-in permissions and guardrails | Agent | **Agent SDK** | Safety features included |

> **Note:** The Agent SDK is for when you want built-in file/web/terminal tools, permissions, and MCP out of the box. If you want to build an agent with your own tools, Claude API is the