CCDV-F Practice Test 8 — 10 Questions

Question 1

A developer is streaming a long Claude response using the Messages API with stream: true. Their client code reads Server-Sent Events and appends text to the UI. Mid-stream, the connection drops and the client reconnects by re-issuing the same request from scratch. Users complain that the answer restarts from the beginning. What is the most accurate explanation of what is happening?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Streaming responses are stateless; a dropped connection cannot be resumed, so re-issuing the request starts a brand new generation and the partial text already shown is discarded.. Streaming responses from the Messages API are not resumable: each HTTP request produces an independent generation delivered as Server-Sent Events. When the transport fails, the client cannot ask the server to continue from the last token it saw. The correct mitigation is to persist partial output locally, avoid blindly restarting the UI, and design retries that tolerate duplicate or truncated content.

Answer

The client must call the count_tokens endpoint before reconnecting so the server can splice the new stream onto the previous tokens.

Answer

The Messages API supports resuming a stream from the last received event, so the client should have sent the last event ID back on reconnect.

Answer

Setting a higher max_tokens on the reconnect lets the API detect the earlier partial output and continue from where it stopped.

Question 2

A developer is building a customer-support agent on the Claude Messages API. The agent receives a long conversation history plus a retrieved knowledge-base article, and the developer wants Claude to answer only from the retrieved article while still seeing the full chat for tone. The developer wants the retrieved article treated as the most authoritative source, even if earlier turns contain outdated policy statements. Where should the retrieved article be placed, and how should it be marked?

Accepted Answer

Place the retrieved article inside the system prompt, wrapped in tags, and instruct Claude that content overrides any conflicting statements in the conversation.. The system prompt is the operator-controlled channel and carries more weight than user or assistant turns, making it the right place to establish that the retrieved article is authoritative. Tagging the article with XML-style delimiters gives Claude an unambiguous boundary for the trusted content, so outdated policy in earlier conversation turns does not win.

Answer

Insert the retrieved article into a tool_result block from a search tool and instruct Claude to prefer tool results over all other content.

Answer

Place the retrieved article as the first user turn, followed by the conversation history, and rely on Claude's recency bias to prefer the article.

Answer

Append the retrieved article as the final assistant turn so Claude treats it as its own prior statement and repeats it verbatim.

Question 3

A developer is integrating the Anthropic API into a healthcare application that processes protected health information (PHI). The compliance team requires that data is encrypted in transit and that the application authenticates to the API without embedding secrets in client-side code. Which combination of practices should the developer implement?

Accepted Answer

Use HTTPS with TLS 1.2 or higher for all API calls and store the Anthropic API key in a server-side secret manager, retrieving it at runtime.. The correct practices are HTTPS with TLS 1.2+ for encryption in transit and a server-side secret manager for the API key. This ensures PHI is protected during transmission and the API key is not exposed in client code, satisfying both compliance requirements.

Answer

Use HTTPS for API calls and store the API key in a client-side configuration file that is bundled with the application.

Answer

Use a VPN for all traffic and hardcode the API key in the server application's environment variables.

Answer

Use HTTP for internal network calls and embed the API key in the mobile app's source code for simplicity.

Question 4

A developer is using the Messages API and wants Claude to reply in strict JSON matching a schema their downstream service expects. They have already written a clear instruction in the system prompt describing the schema. Which additional API feature most directly enforces that the output conforms to the schema?

Accepted Answer

Defining a tool whose input_schema describes the desired fields, then instructing Claude to call that tool for its response.. Tool definitions carry a JSON Schema in input_schema, and when Claude invokes a tool, the API returns arguments that conform to that schema. Routing the model's answer through a tool call therefore gives the strongest structural guarantee in the Messages API. Prompt instructions help guide behavior but do not enforce shape, so pairing them with a tool schema is the reliable pattern for strict JSON.

Answer

Setting temperature to 0 to eliminate all variation in the response format.

Answer

Increasing max_tokens so the model has room to complete the full JSON object without truncation.

Answer

Adding a stop_sequence equal to the closing brace so the API halts generation exactly at the end of the JSON.

Question 5

A developer is integrating Claude into a customer-facing portal where users can paste arbitrary text that is inserted into prompts. The security team wants to reduce the risk of prompt injection leading to unauthorized actions. Which TWO controls are most effective? (Choose two.)

Accepted Answer

Delimit and clearly label untrusted user content within the prompt, instructing Claude to treat it as data rather than instructions.. Prompt injection defense requires both reducing the model's tendency to follow injected instructions and ensuring that no unauthorized action succeeds regardless of model output. Delimiting untrusted content addresses the first layer, while server-side authorization enforcement addresses the second and is the control that actually prevents harm when injection attempts succeed.

Answer

Increase the max_tokens setting so Claude has more room to reason about whether input is malicious.

Answer

Cache responses for identical user inputs to reduce the number of times Claude processes potentially malicious text.

Answer

Lower the temperature to zero so Claude becomes deterministic and cannot be manipulated.

Question 6

A developer is building a customer-support assistant that must answer only from a provided knowledge base article and must refuse to answer when the article does not contain the information. The assistant currently invents plausible answers. Which prompt change best enforces the refusal behavior?

Accepted Answer

Instruct the model to answer only using information found in the article and to respond with a fixed phrase such as 'I don't have that information' when the article is insufficient.. Grounding requires two explicit constraints: define the permitted source and define what to do when that source is inadequate. Naming the article as the only allowed source, plus a fixed refusal phrase for missing information, gives the model an unambiguous rule and produces a consistent, detectable abstention. Tone, token limits, and document placement do not establish either constraint.

Answer

Increase the max_tokens parameter so the model has more room to explain its reasoning.

Answer

Move the knowledge base article to the end of the prompt so it is the last thing the model reads.

Answer

Add an instruction to answer in a polite and professional tone at all times.

Question 7

A developer is writing an MCP client that must stay responsive while a server performs a slow operation during a tool call. The client should allow the user to cancel the request without terminating the whole session, and the server should be able to stream incremental output before finishing. Which two MCP features should the developer implement? (Choose two.)

Accepted Answer

Request cancellation using the notifications/cancelled notification with the in-flight request ID.. Long-running MCP operations are handled with progress notifications tied to a client-supplied progress token and with out-of-band cancellation via notifications/cancelled. Together they let a server report partial progress and let a client abort one request without disturbing the session, which is precisely the behavior the scenario demands.

Answer

Polling tools/list repeatedly to detect when the tool has finished executing.

Answer

Closing the transport and reinitializing the session to interrupt the operation.

Answer

Setting a long client-side timeout and retrying the same request until it succeeds.

Question 8

A developer is using the Anthropic API to build a customer support chatbot. The chatbot must access a backend CRM to retrieve customer details. The security team requires that the chatbot only accesses records for the authenticated customer and that the CRM credentials are never exposed to the model. Which approach best satisfies these requirements?

Accepted Answer

Implement a backend service that authenticates the user, retrieves the customer ID, and calls the CRM with its own credentials, then returns only the necessary data to Claude.. The best approach is a backend service that authenticates the user, retrieves the customer ID, and calls the CRM with its own credentials, returning only necessary data to Claude. This keeps credentials server-side and enforces that the chatbot only accesses records for the authenticated customer.

Answer

Pass the CRM API key to Claude in the system prompt so it can include the key when calling the CRM tool.

Answer

Store the CRM credentials in the model's fine-tuning data so it can learn to call the CRM securely.

Answer

Have Claude generate CRM API calls and execute them directly from the client-side application using the customer's browser session.

Question 9

A developer is building a real-time chat application where users expect responses in under two seconds. The prompts are short (under 200 tokens) and the responses are typically one or two sentences. Which Claude model should the developer choose to optimize for latency and cost?

Accepted Answer

Claude 3 Haiku. For a real-time chat application with short prompts and simple responses, latency and cost are critical. Claude 3 Haiku is specifically designed to be the fastest and most affordable model in the Claude 3 family, making it ideal for this use case. More powerful models like Opus or Sonnet would add unnecessary cost and latency without providing meaningful benefits for such straightforward interactions.

Answer

Claude 3.5 Sonnet

Answer

Claude 3 Opus

Answer

Claude 2.1

Question 10

A developer's MCP client sends a tools/call request for a tool that performs a database write. The tool result comes back with is_error set to true and a message about a unique-constraint violation. What is the most appropriate way for the client to handle this result?

Accepted Answer

Surface the error content to Claude as the tool result so it can reason about the failure and adjust its next action.. Tool errors are delivered in-band as a tool result with is_error set to true, and the accompanying content is meant to inform the next reasoning step. Returning that result to Claude preserves the conversation loop and lets the model adapt, which is the correct handling for a recoverable data-level failure such as a constraint violation.

Answer

Convert the tool result into a plain assistant text message and end the turn without invoking Claude again.

Answer

Terminate the MCP session and reconnect before retrying the tool call.

Answer

Discard the result and silently retry the identical tool call up to three times.