Lenses vs Raystack Stencil

Lenses describes its Operating Fabric as a platform for building, governing, and operating Kafka applications with engineers and AI agents. Users can discover streaming data across domains with SQL, prepare it for consumption, and deploy data streams independently. It connects to Confluent Platform, Confluent Cloud, Amazon MSK, Redpanda, and self-managed Apache Kafka, and can run in cloud, on-premises, or hybrid environments. Work interfaces include a Web App, VS Code Extension, Lenses MCP, and Lenses CLI. Lenses says OAuth 2.1 gives agents scoped, short-lived, revocable, and audited access. It also lists open-source Kafka connectors for systems including Amazon S3, Azure Event Hubs, GCP Storage, Cassandra, MongoDB, Redis, and Elasticsearch; the connectors are Apache 2.0 licensed and have enterprise support. The DevX Community Edition supports up to five free users, while SQL Studio supports up to two Kafka clusters. A trial key is available through the guided demo. Team Edition is listed from $4,000 per year and supports up to 15 users with SSO/SAML, RBAC, and Team Support.

Raystack Stencil is a schema registry for managing schema definitions and checking data compatibility across applications. It supports Protobuf, Avro, and JSON, and keeps versioned histories of proto descriptor files organized by namespace and name. Uploads receive backward-compatibility checks by default, though some checks can be skipped. The service provides APIs for retrieving the latest version number for a schema name and namespace and downloading the proto descriptors contained in a specified message. Its server offers gRPC and HTTP interfaces, while a CLI can create, view, and search schemas. Listed client libraries cover Java, Go, JavaScript, and Clojure. Clients can download descriptor sets, deserialize Protobuf messages, look up descriptors, and refresh schema definitions with built-in strategies. Stencil can run from a Docker image or be compiled from source, with installation options for macOS, Windows, Linux, OpenBSD, and FreeBSD. The server requires PostgreSQL 13. Refreshing a descriptor after encountering unknown fields is supported only by the Java and Go clients. The project is open source under Apache-2.0.