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Assistant Prefill

Start the model's reply for it — guarantees determinism for JSON, XML, code outputs.

1 hours1 resources1 prereqs

In Anthropic's API, if you write the start of the assistant message, the model must continue from there.

Classic uses:

  • Start with { → JSON guaranteed
  • Start with <answer> → XML scaffold
  • Sure! Here's the code:\n\``python\n` → skip filler preamble

Not directly supported in OpenAI, but few-shot achieves similar effect.

Prerequisites

Resources(1)