BitDive vs Karapace

BitDive is a freemium API, web, and self-hosted tool for Java and Kotlin teams that want to verify code changes against recorded service behavior. Its agent captures method calls, SQL queries, HTTP requests, Kafka messages, JVM metrics, and exception traces, then compares behavior before and after changes to reveal SQL drift, extra HTTP calls, and performance regressions. Recorded executions become replayable JUnit 5 tests that run with standard Maven or Gradle tooling. The agent supports Java 8 through 21 and captures bytecode behavior without source changes. BitDive exposes runtime context and trace operations through MCP for Cursor, Windsurf, and Claude. It lists 49 supported technologies, including Spring Boot, PostgreSQL, MongoDB, Kafka, JUnit 5, Testcontainers, and Maven. Deployment options include hosted SaaS, on-premise, and air-gapped installations. Security details specify TLS 1.3 in transit, AES-256 at rest, and in-JVM masking of sensitive fields. Developer Use costs nothing; Company Rollout pricing is custom.

Karapace is a free, open-source implementation of the Kafka Schema Registry and Kafka REST Proxy. Its registry stores Avro, JSON Schema, and Protobuf schemas, keeps version histories, and checks compatibility between versions. The REST Proxy exposes HTTP APIs for producing and consuming Kafka events and handling administrative operations. Karapace implements the Confluent Schema Registry API and REST Proxy API versions 1 and 2, with version 2 as the default. A leader-and-replica design provides high availability and load balancing. Monitoring includes Prometheus-native metrics and OpenTelemetry traces and metrics, with optional Sentry reporting. Schema Registry authentication supports HTTP basic authentication and OAuth2/OIDC bearer-token validation; the REST Proxy forwards OAuth2 tokens instead of validating them. Karapace is self-hosted, requires Python 3.12 or newer, and installs from Docker images or source. Default Docker ports are 8081 for the Schema Registry and 8082 for the REST Proxy. It is offered at free.