The Claude API section for developers who want to build on Anthropic’s models rather than just chat with them. Everything here is written from working code — real requests, real responses, real invoices — covering the Messages API, SDKs, and the platform features that matter in production.
Start with the complete Claude API developer’s guide, then follow the tutorial for your first integration. The pricing article breaks down every tier — from Haiku 4.5 at $1/$5 per million tokens up to Fable 5 at $10/$50 — including prompt caching and batch discounts that can cut your bill dramatically. Language-specific guides walk through Python and Node.js implementations step by step, and there are dedicated articles on getting your API key, understanding rate limits, and estimating spend with an interactive cost calculator.
The guides reflect the 2026 platform: adaptive thinking, the effort parameter, structured outputs, 1M-token context windows on current Opus, Sonnet, and Fable models, and the removal of temperature on newer models — the kind of changes that quietly break old tutorials elsewhere. If you’re going from claude.ai user to API builder, this section takes you from key creation to your first production deployment.
Claude fast mode is a research preview that serves the same Opus model at up to 2.5× higher output tokens per second — for premium pricing. It is not a different model, not a distilled variant, and not smarter or…
You don’t need a spreadsheet plugin to price a Claude project — you need the current rate card, one formula, and honest token estimates. This claude api cost calculator walks through all three: the full 2026 pricing tables, the tokens-to-dollars…
Claude api rate limits are enforced per organization, per model, along three axes: requests per minute (RPM), input tokens per minute (ITPM), and output tokens per minute (OTPM). Exceed any one of them and the API returns a 429 with…
Integrating the claude api nodejs stack comes down to one package: @anthropic-ai/sdk, Anthropic’s official TypeScript SDK. It ships full type definitions, automatic retries, and streaming helpers, and it works identically in plain JavaScript. This guide takes you from npm install…
Calling the Claude API from Python takes three lines: install the anthropic package, set your API key, and call client.messages.create(). This claude api python guide walks through everything I actually use in production — client setup, streaming, tool use, structured…
This Claude API tutorial takes you from an empty folder to a working Python integration — install, authentication, your first call, streaming, and production-grade error handling — in about twenty minutes. Every code block below runs as-is against the current…
Claude API pricing is pay-as-you-go, billed per million tokens (MTok), with a separate rate for input and output. As of July 2026 the three models you’ll actually choose between cost $5/$25 (Opus 4.8), $3/$15 (Sonnet 5 — introductory $2/$10 through…
Getting a Claude AI API key takes about five minutes: create an account at platform.claude.com, add billing, open the API Keys page, and generate a key. The key is shown exactly once, starts with sk-ant-, and authenticates every request you…
The Claude API gives you programmatic access to Anthropic’s Claude models through a single HTTPS endpoint: POST You send a list of messages, you get a model-generated response back, and everything else — tool use, structured outputs, extended reasoning,…