Study · Claude Course

Anthropic API Basics

Call the API **server-side only** (never from a client — protects the key). Core call is

type conceptstatus activeapi · anthropic · sdk

client.messages.create(model, max_tokens, messages); the API is stateless, so you resend the full conversation history every turn.

Key points

  • max_tokens is a safety cap, not a target length; generation stops there or at an end-of-sequence token (stop_reason).
  • System prompt (system=) controls how Claude responds (tone/role), not what.
  • Temperature 0–1: low = deterministic/extraction, high = creative/varied.
  • Streaming (messages.stream()) renders chunk-by-chunk via content_block_delta for UX; get_final_message() reassembles for storage.
  • Pipeline: tokenization → embedding → contextualization → generation.
Claude-Models · Controlling-Output · Prompt-Caching · Extended-Thinking

Sources

  • 2026-06-28-claude-course
Compiled from wiki/study/claude-course/Anthropic-API-Basics.md · git is the source of truth