3.2.1.3. Response Control and Formatting

3.2.1.3. Response Control and Formatting

Response control parameters determine how the model structures its output. For applications that need to parse responses programmatically, structured output is essential—free-form text requires fragile regex parsing.

Key response control mechanisms:

• response_format: {"type": "json_object"}: Forces valid JSON output
• stop sequences: Tell the model when to stop generating (e.g., ["\n", "User:"])
• max_tokens: Hard limit on response length (prevents runaway costs)
• Function calling: Structured tool invocation with validated parameters