Glossary · Phase 1 · Building with LLMs
JSON schema
A precise description of the JSON you expect: which fields, what type each is, and which are required.
A JSON schema is the blank form. It describes the data you expect: which fields there are, and what kind of value goes in each one. The schema is itself written as JSON. In Python, that means a dictionary.
Try it now
An example response with structured output, trimmed. The JSON is a string inside the text block. A thinking block comes before it, and your code still needs to skip that.
Learn it properly
Structured output · Get reliable JSON back that your code can use. About 30 minutes.
Other terms from the same lesson
- SDK: Software development kit: a ready-made library for calling a service from your code, such as Anthropic's Python SDK.
- structured output: Asking a model to answer in an exact format, such as JSON with set fields, so code can use it.
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