A downstream service consumes Claude's output as JSON. Occasionally Claude wraps the JSON in a short…

Question

A downstream service consumes Claude's output as JSON. Occasionally Claude wraps the JSON in a short preamble such as "Here is the result:" and the parser fails. The prompt currently just says "Return JSON." Which combination of techniques most reliably produces machine-parseable output?

Accepted Answer

A. Define the exact schema with field types and allowed values, instruct that the response must contain only the JSON object with no prose, provide a worked example, and validate the parsed result with a retry that feeds back the validation error

Answer

B. Raise max_tokens and lower temperature only

Answer

C. Ask Claude to apologize if it adds a preamble and then repeat the answer

Answer

D. Instruct Claude to reason step by step at length inside the same JSON string field before answering

Question 293