{
  "title": "Building with the Claude API: knowledge check",
  "description": "A 12-question multiple-choice check for developers who have just finished an intro course on the Claude Messages API. Demo content written for this project.",
  "items": [
    {
      "id": "Q01",
      "objective": "Recognize when output was cut off by the token limit",
      "stem": "A response stops mid-sentence. Which stop_reason tells you the output hit the max_tokens limit you set?",
      "options": {
        "A": "end_turn",
        "B": "max_tokens",
        "C": "stop_sequence",
        "D": "tool_use"
      },
      "key": "B"
    },
    {
      "id": "Q02",
      "objective": "Continue a tool-use loop correctly",
      "stem": "Claude replies with stop_reason \"tool_use\". What should your code do next?",
      "options": {
        "A": "Send the exact same request again",
        "B": "Run the requested tool and send the output back as a tool_result block in a new user message",
        "C": "Paste the tool output into the system prompt and start a new conversation",
        "D": "Treat it as an error and retry with a higher max_tokens"
      },
      "key": "B"
    },
    {
      "id": "Q03",
      "objective": "Return parallel tool results correctly",
      "stem": "In one turn, Claude asks for three different tool calls. How should you return the three results?",
      "options": {
        "A": "Three separate user messages, one result in each",
        "B": "One user message that holds all three tool_result blocks",
        "C": "Only the first result, since Claude will ask for the others again",
        "D": "One assistant message that holds all three results"
      },
      "key": "B"
    },
    {
      "id": "Q04",
      "objective": "Report a failed tool call to Claude",
      "stem": "One of your tools throws an exception while running. What is the recommended way to tell Claude?",
      "options": {
        "A": "Leave the tool_result out so Claude moves on",
        "B": "Return a tool_result with is_error set to true and a short description of what went wrong",
        "C": "Return an HTTP 500 from your app so the SDK retries",
        "D": "Start a new conversation without the tool"
      },
      "key": "B"
    },
    {
      "id": "Q05",
      "objective": "Place the main system prompt in a request",
      "stem": "Where does the main system prompt go in a Messages API request?",
      "options": {
        "A": "In the messages array, as a message with role \"system\"",
        "B": "In the top-level system parameter",
        "C": "In the metadata field of the first user message",
        "D": "In a custom request header"
      },
      "key": "B"
    },
    {
      "id": "Q06",
      "objective": "Explain why a prompt cache misses",
      "stem": "You add the current timestamp to the very top of your system prompt, and your cache hit rate drops to zero. Why?",
      "options": {
        "A": "Cached prompts expire every 60 seconds",
        "B": "Caching is a prefix match, so a change near the start invalidates everything after it",
        "C": "Timestamps are not allowed in system prompts",
        "D": "Caching only applies to tool definitions"
      },
      "key": "B"
    },
    {
      "id": "Q07",
      "objective": "Verify that caching is working",
      "stem": "How can you confirm that a cached prefix was actually reused on a request?",
      "options": {
        "A": "Check usage.cache_read_input_tokens in the response",
        "B": "Compare response times and assume faster means cached",
        "C": "Check whether stop_reason is \"cached\"",
        "D": "Look for a [cached] marker at the start of the response text"
      },
      "key": "A"
    },
    {
      "id": "Q08",
      "objective": "Get output that always matches a JSON schema",
      "stem": "Your app needs Claude's answer to match a JSON schema every time. What is the most reliable option?",
      "options": {
        "A": "Add \"respond only in JSON\" to the end of the prompt",
        "B": "Use structured outputs, for example output_config.format or messages.parse in the SDK",
        "C": "Parse the reply with a regular expression and retry on failure",
        "D": "Give three JSON examples in the system prompt"
      },
      "key": "C"
    },
    {
      "id": "Q09",
      "objective": "Guarantee schema-valid tool inputs",
      "stem": "You want every tool call's input to validate exactly against that tool's input_schema. What do you set?",
      "options": {
        "A": "strict: true on the tool definition",
        "B": "strict: true inside tool_choice",
        "C": "A higher max_tokens value",
        "D": "A json-mode request header"
      },
      "key": "A"
    },
    {
      "id": "Q10",
      "objective": "Interpret a 429 response",
      "stem": "Your app starts getting HTTP 429 responses. What do they mean, and what is the right response?",
      "options": {
        "A": "The API key is invalid, so rotate it",
        "B": "You hit a rate limit, so back off and retry (the SDKs retry with exponential backoff)",
        "C": "The request body is too large, so split it",
        "D": "The model has been retired, so switch models"
      },
      "key": "B"
    },
    {
      "id": "Q11",
      "objective": "Decide which errors to retry",
      "stem": "Which of these errors is NOT worth retrying automatically without changing the request?",
      "options": {
        "A": "429 rate_limit_error",
        "B": "529 overloaded_error",
        "C": "500 api_error",
        "D": "400 invalid_request_error"
      },
      "key": "D"
    },
    {
      "id": "Q12",
      "objective": "Match batch results to requests",
      "stem": "You submit 1,000 requests through the Message Batches API. How should you match each result to its request?",
      "options": {
        "A": "By position, since results come back in the order you sent them",
        "B": "By the custom_id you gave each request",
        "C": "By the timestamp on each result",
        "D": "By input token count, since results are sorted by size"
      },
      "key": "B"
    }
  ]
}