Tag: json

2 articles

Fix: msgspec Not Working — Struct Definition, Type Validation, and JSON/MessagePack Encoding

May 11, 2026

How to fix msgspec errors — Struct field type not supported, ValidationError on decode, msgspec vs Pydantic differences, custom type hooks, frozen Struct mutation, and JSON Schema generation.

python msgspec serialization json msgpack fastapi debugging

Fix: SyntaxError: Unexpected token < in JSON at position 0

Dec 30, 2025

How to fix 'Unexpected token in JSON at position 0', 'JSON.parse: unexpected character', and 'Unexpected end of JSON input' in JavaScript and TypeScript. Covers API returning HTML instead of JSON, Content-Type mismatches, fetch URL typos, invalid JSON syntax, BOM characters, CORS proxies, and debugging with response.text().

javascript json api fetch typescript