grpcui vs Kreya

grpcui is a free, open-source command-line tool for interacting with gRPC servers through a browser-based interface. It is aimed at gRPC APIs rather than REST APIs and can discover service schemas through server reflection, .proto source files, or compiled protoset files. Its interface builds dynamic forms for protobuf messages, including well-known types, oneofs, and maps, and also accepts a complete JSON request body. grpcui supports RPC methods including streaming, then displays response headers, messages or errors, trailers, and readable HTML tables. It connects to plaintext and TLS servers, including mutual TLS with client certificates. Streaming requests have a constraint: they must be constructed all at once, so bidirectional streams cannot be handled interactively like they can with grpcurl. The project also provides Go packages for embedding a form or complete web UI in a Go HTTP server. Installation is documented through Homebrew on macOS or Linux, and through the Go install command. It is released under the MIT license.

Kreya is a desktop API client for exploring, testing, and automating API workflows on Linux, macOS, and Windows. It works with gRPC, REST, GraphQL, WebSockets, and Server-Sent Events, and can watch or import OpenAPI specifications, GraphQL schemas, and protobufs. Testing options include scripted checks and snapshot tests; its headless CLI can run in CI/CD and generate JUnit reports. Projects are kept in structured JSON intended to support Git diffs, reviews, and versioning. Kreya can import Postman and Insomnia collections, plus HAR, cURL, gRPCurl, and grpc web curl data. A reusable authentication vault covers OAuth 2.0, OIDC, Basic, API keys, mTLS, AWS SigV4, Kerberos, NTLM, and JWT Profile. The maker says app data stays on the device, while its privacy policy says the app and CLI collect anonymized telemetry. There is a free plan; Pro is $5 a month. Secret manager integration is marked as coming soon.