Question

A developer is building a customer-support classification service using the Bedrock Converse API with Anthropic Claude. The service must classify incoming messages into one of five fixed categories and return only the category label. During testing, the model occasionally adds explanatory sentences, uses category names not in the approved list, or varies the label casing. The team wants the most reliable way to enforce consistent, constrained output while keeping the solution simple and portable across supported Converse-compatible models. What should the developer do?

Accepted Answer

Provide a system prompt that defines the exact allowed labels and output format, and include several few-shot input/output examples in the messages array demonstrating the required response.

Answer

Increase the temperature and top_p inference parameters so the model explores more completions and eventually settles on the correct label.

Answer

Switch from the Converse API to the legacy InvokeModel API because only it supports deterministic classification output.

Answer

Attach a Bedrock Guardrail with a denied-topics policy listing the five categories to force the model to respond with a valid label.