JSON Mode
Provider feature that constrains model output to valid JSON. Weaker guarantee than structured output (which can enforce schemas), but useful when only well-formed JSON is required.
Related terms
- Structured Output
Model-side support for producing responses that conform to a declared schema (JSON Schema, Pydantic model, OpenAI's response_format). Reduces brittle string parsing in tool-use pipelines and is a prerequisite for reliable agent execution.
- Function Calling
Provider-side support for models emitting structured JSON that matches a declared function signature, so runtime can safely parse and dispatch tool invocations. Analogous to MCP tool calling but predates MCP as a proprietary provider capability.
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Next steps
- Take the assessment— See where you stand
Call this framework and its tools from your own agent via the Model Context Protocol (MCP) server. Works with Claude Desktop, Cursor, Zed, Continue, and the OpenAI Agents SDK.
Where this fits
JSON Mode is part of the Agentic AI vocabulary used in the Generative AI Maturity Framework. See the full glossary for the complete set of 149 defined terms, or take the free maturity assessment to see where your organisation stands.