Anthropic API: Claude, Tool Use, and Structured Outputs in Apps

This post was created with AI assistance and reviewed for accuracy before publishing. Anthropic documents the Messages API, models, and tool use for Claude at Anthropic API documentation. Model IDs, pricing, and capabilities are versioned; copy model strings from the console or docs, not from old blog posts. Tools Tool calling lets Claude request structured actions (HTTP, DB, internal functions) that your server executes. Validate arguments with schemas before execution. Structured workflows When you need machine-readable output, combine tool use with strict validation in your own code.