grpcui vs ProtoCall

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.

ProtoCall is a cloud web app intended to simplify the steps of building APIs with gRPC. It runs in a browser without installation and organizes proto files into workspaces, where packages and imports resolve within one namespace. Users can create a workspace by importing proto files manually or bring in a GitHub repository they own, collaborate on, or can access through organization membership. Imports can track repository changes automatically. ProtoCall supports one repository per workspace, not a combination of repositories. The web app relies on ProtoCall Agent, a local webserver, for outbound requests that browsers cannot make directly because of CORS restrictions. The agent applies its own CORS rules and additional authentication to restrict communication from unauthorized non-browser processes. The agent runs through a Docker container on Windows and macOS, and as a binary executable on Linux. The Free plan costs nothing and supports GitHub imports and manually created workspaces. Listed platforms are Linux, macOS, web, and Windows.