Output Schema → Prompt Instruction

Paste a JSON Schema; get the prompt text that asks an LLM to produce matching JSON. Useful when you want structured output but the model doesn't support native JSON Schema mode (older models, some open-weight inference providers), or when you want the prompt to be self-documenting.

How to use the Output Schema → Prompt Instruction

Paste a JSON Schema. The tool generates prompt text: an introduction explaining the expected output, the schema inline as a code block, and (in strict mode) a reminder to emit valid JSON with no surrounding prose. Append this to your task prompt.

Turning a JSON Schema into prompt text

Newer models accept a JSON Schema directly and guarantee conforming output, but plenty of situations still call for asking in plain prompt text: older models, some open-weight inference providers, or simply wanting the prompt to be self-documenting so anyone reading it can see the expected shape. The translation from schema to clear instruction is mechanical but tedious to do by hand.

This tool reads a JSON Schema and writes the prompt text that asks an LLM to produce matching JSON — an introduction describing the output, the schema inline as a code block, and, in strict mode, a reminder to emit valid JSON with no surrounding prose. Append it to your task prompt. When the reply comes back wrapped in fences or commentary, the JSON extractor pulls the clean object out.

Common use cases

  • Models without schema mode — ask for structured output where native JSON Schema isn't supported.
  • Self-documenting prompts — embed the expected shape so the prompt explains itself.
  • Open-weight inference — get structured output from providers that lack a schema parameter.
  • Prototyping — turn a schema into a working instruction without writing the wording.
  • Consistent output — remind the model to return only valid JSON, no prose.

Frequently asked questions

When would I use this over native JSON Schema mode?
For models or providers that don't support a schema parameter, or when you want the prompt itself to document the expected output for readers.

What is in the generated instruction?
An introduction describing the output, the schema inline as a code block, and — in strict mode — a reminder to emit valid JSON with no surrounding text.

Does asking in text guarantee valid JSON?
No — it strongly encourages it but can't guarantee it the way a schema-constrained API can. Parse the reply with the JSON extractor to handle stray prose.

What is the difference between strict and brief styles?
Strict adds the output reminder and framing; brief emits just the schema. Use strict when the model tends to add commentary, brief when it already behaves.
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