OpenAI Function Calling: The Complete Guide to Structured JSON Output
Everything you need to know about OpenAI function calling and Structured Outputs in 2026 — schemas, strict mode, tool choice, and production patterns.
Developer guides on JSON, TypeScript, Zod, LLMs, and modern tooling.
Everything you need to know about OpenAI function calling and Structured Outputs in 2026 — schemas, strict mode, tool choice, and production patterns.
LLMs produce unreliable JSON. Here's the production-grade pattern for parsing, repairing, and validating LLM output with Zod — with real error handling.
Three mature validation libraries, three different design philosophies. Here's when to use Zod, Yup, or Joi — with real performance numbers and migration advice.
JSON.parse throws cryptic errors. Here are the 7 errors you'll hit most often, what they mean, and the exact fix for each.
LLMs produce broken JSON constantly — trailing commas, single quotes, Python literals, markdown fences. Here's why it happens and how to fix it in production.