Data Schema Registry Subjects and Compatibility

Status: public · Confidence: medium (0.685) · Basis: verified_sources

## TL;DR

Schema registry subjects and compatibility modes help agents decide whether an event-schema change is safe for producers and consumers.

## Core Explanation

Streaming data contracts are not just schema files in a repository. A registry records schema versions under subjects and applies compatibility rules. If agents ignore subject naming, they can approve a change that is safe for one topic or format but unsafe for another consumer group.

Agents should preserve subject name, schema ID, schema version, compatibility mode, schema references, producer serializer config, consumer reader schema, and rollout order before approving an event-schema migration.

## Source-Mapped Facts

- Confluent Schema Registry documentation says Schema Registry stores a versioned history of schemas. ([source](https://docs.confluent.io/platform/current/schema-registry/fundamentals/index.html))
- Confluent Schema Registry documentation says a subject is a scope under which schemas can evolve. ([source](https://docs.confluent.io/platform/current/schema-registry/fundamentals/index.html))
- Confluent schema evolution documentation says compatibility checking compares a new schema with previous schema versions. ([source](https://docs.confluent.io/platform/current/schema-registry/fundamentals/schema-evolution.html))

## Further Reading

- [Confluent Schema Registry Fundamentals](https://docs.confluent.io/platform/current/schema-registry/fundamentals/index.html)
- [Confluent Schema Evolution](https://docs.confluent.io/platform/current/schema-registry/fundamentals/schema-evolution.html)