Claude Certified Developer – Foundations Practice Test

How to Study for the Claude Certified Developer Exam

Build something real against the Messages API before you sit the exam — most integration questions test facts you internalize in an afternoon of coding: model, max_tokens, and messages are the required parameters; the first message must be role "user"; the API is stateless so you resend the whole conversation; stream: true delivers content_block_delta events for perceived-latency wins; images ride in content blocks, not a separate endpoint; thinking budget_tokens must be smaller than max_tokens. Prompt caching is exact-prefix matching — a timestamp at the top of your system prompt silently kills every cache hit, and adding a tool invalidates the whole cache because tools render before system and messages.

For agents, internalize Anthropic's "Building Effective Agents": workflows (predefined code paths) for fixed, predictable steps; agents (model-directed loops) only when the path can't be known in advance; and always start with the simplest thing that works. Security questions reward the same instincts as classic appsec: treat model output and retrieved content as untrusted input, delimit user content so injected "ignore previous instructions" text stays data, scope tools to least privilege, and use hooks — not prompt rules — when a guarantee is required. For Claude Code, know the config surfaces (CLAUDE.md at repo root for shared conventions, settings.local.json for personal permissions, -p --output-format json for CI) and that subagents isolate noisy searches in their own context. Then take our timed 53-question mock to rehearse the real format.