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Fix Pydantic v2 Errors: ValidationError Details, Strict Types and v1 Migration Breakage

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Self-Hosting & Infra intermediate 7 min read $0.01 Updated 2026-10-20

Pydantic v2 troubleshooting: reading errors() output, missing and extra fields, type coercion versus strict mode, Optional defaults, field_validator and model_validator, ConfigDict, model_dump, model_validate, and bulk migration with bump-pydantic.

Pydantic raises ValidationError or your v1 code breaks after upgrading. Read error locations and types, understand coercion and strict mode, and migrate validators, Config, dict and parse_obj.

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#pydantic#python#validation#fastapi#migration

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