Overview

CLI, SDKs, and libraries

Official tools for building with the Claude API: the ant CLI, client SDKs in seven languages, and framework-specific libraries.

Anthropic provides three kinds of official tooling for building with the Claude API:

CLI: The ant command-line tool for shell scripting and interactive use.
Client SDKs: General-purpose Messages API clients for Python, TypeScript, C#, Go, Java, PHP, and Ruby. Each SDK provides idiomatic interfaces, type safety, and built-in support for streaming, retries, and error handling.
Libraries and integrations: Packages and compatibility layers that expose Claude inside another framework's API surface rather than the Messages API directly.

For the full API specification, see the API reference.

CLI

Shell scripting, typed flags, response transforms

Client SDKs

Sync and async clients, Pydantic models

Node.js, Deno, Bun, and browser support

.NET Standard 2.0+, IChatClient integration

Context-based cancellation, functional options

Builder pattern, CompletableFuture async

Value objects, builder pattern

Sorbet types, streaming helpers

Libraries and integrations expose Claude through another framework's API surface. They are not general-purpose Messages API clients.

Use Claude through the OpenAI SDK surface

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CLI, SDKs, and libraries

Official tools for building with the Claude API: the ant CLI, client SDKs in seven languages, and framework-specific libraries.

Anthropic provides three kinds of official tooling for building with the Claude API:

CLI: The ant command-line tool for shell scripting and interactive use.
Client SDKs: General-purpose Messages API clients for Python, TypeScript, C#, Go, Java, PHP, and Ruby. Each SDK provides idiomatic interfaces, type safety, and built-in support for streaming, retries, and error handling.
Libraries and integrations: Packages and compatibility layers that expose Claude inside another framework's API surface rather than the Messages API directly.