Messages API

See how user and assistant roles alternate across multi-turn conversation turns.

Send a multi-turn request with alternating user and assistant role messages.

Maintain conversation state by resending the full messages array on each turn.

Reference table for text, image, tool_use, and tool_result content block types.

Write a system prompt that sets persona, constraints, and output format reliably.

Numbered practices for structuring roles, turns, and content blocks reliably.