Pydantic 3 Drops V1 Support and Adds Paid Enterprise Contracts

Pydantic, the widely used Python data-validation and settings library, has published its roadmap for version 3. The plan limits breaking changes, ends support for V1, and introduces paid enterprise support for companies that need contractual response times.

The project ranks among PyPI’s 20 most downloaded packages, with more than 800 million downloads per month, according to its maintainers. That reach makes compatibility central to the V3 release strategy.

V3 keeps breakage narrow

The V1-to-V2 migration replaced Pydantic’s validation core with pydantic-core , written in Rust, and changed validators, configuration, and serialization APIs. The V3 plan limits breaking changes to two categories:

• Correctness fixes: changes that repair incorrect behavior affecting a limited group of users, including code that may rely on the bug.
• Reversible behavior changes: changes that provide a supported way to restore the previous behavior.

V3 will also remove legacy APIs deprecated in V1 and drop the pydantic.v1 compatibility namespace. The maintainers do not plan another API redesign on the scale of V2.

Maintainers are collecting changes that require a major release in a dedicated V3 tracker . They expect to address as many of those issues as practical, without committing to the full list. No release date has been announced; the current target is to have V3 close to its final form by year-end.

V1 support stops at 1.10.27

Pydantic 1.10.27 is the final V1 release and includes security fixes recorded in the release changelog. The same fixes ship in the pydantic.v1 namespace included with Pydantic 2.14.2.

Future security flaws in standalone V1 or the legacy namespace will not receive patches, even when the namespace is installed through a V2 package. Native V2 remains supported, with no end date set. The maintainers say they will continue that support until most users have moved to V3.

Paid support adds SLAs

Pydantic remains MIT-licensed and open source. New enterprise support contracts provide direct access to maintainers, 24/7 priority support, setup assistance, and negotiated service-level agreements. Coverage includes:

• Production incident triage: engineers help reproduce failures, isolate the validation boundary, and identify a mitigation or fix.
• Upgrade reviews: maintainers assess changes to Python, Pydantic, pydantic-core , and key integrations before deployment.
• Implementation guidance: teams can get help with schemas, validators, serialization, and high-throughput validation.
• Security coordination: covered organizations can coordinate privately on impact, mitigations, patched releases, and disclosure.

Pydantic does not publish enterprise pricing. Interested companies must contact sales to define covered release lines, response targets, and other contract terms.

Plan the upgrade by version

1. Standalone V1 users: update to 1.10.27 if migration cannot begin immediately, then move validators, configuration, serialization, and tests to native V2 APIs.
2. V2 projects using pydantic.v1: inventory compatibility imports and replace them before adopting V3, where the namespace will no longer exist.
3. Native V2 users: continue installing minor releases, monitor the V3 tracker, and test release candidates against validation, schema-generation, and serialization behavior.
4. Teams requiring contractual support: evaluate the enterprise plan based on incident-response, security-coordination, and SLA requirements.

The roadmap pairs a conservative major-release policy with paid contracts for organizations that need guaranteed support. V2 users can expect a contained migration if the compatibility plan holds, while V1 users now face an unsupported validation layer and a clear deadline to move.