grpcurl

What grpcurl is

grpcurl is a command-line tool for calling methods on gRPC servers. It accepts request messages in JSON and converts them to the protobuf binary format expected by the service, making it usable from a terminal or in scripts and command pipelines. Its list and describe commands let users inspect available services, methods, and schema details. grpcurl can learn a server’s schema through reflection, or use .proto source files or compiled protoset files. When reflection is unavailable, one of those files is needed to understand the service schema.

The tool supports streaming RPCs, including interactive bidirectional sessions that use a terminal and stdin. Connections can use TLS or plaintext; TLS options include mutual TLS client certificates. grpcurl is available for Linux, macOS, and Windows, and can also be used in self-hosted environments. The project documents installation through release binaries, Homebrew, Docker, Snap, source builds, and third-party packages. It also provides a Go library package for building command-line tools that invoke gRPC endpoints dynamically. The project identifies its license as MIT. grpcurl is free, with no paid plans or usage limits stated.

Who it suits

grpcurl suits developers and operators who need to call gRPC methods from a command line, send JSON requests, or inspect a service schema. It can also suit people building Go command-line tools that need to invoke gRPC endpoints dynamically.

Getting started

1. Open the grpcurl project website on GitHub.
2. Choose a documented installation route: release binary, Homebrew, Docker, Snap, source, or a third-party package.
3. Install grpcurl on Linux, macOS, or Windows.
4. Use server reflection or provide proto source files or a protoset file when the server does not expose reflection.
5. Send JSON request messages to invoke gRPC methods, or use list and describe to inspect the service.

Verdict

Choose grpcurl when you need a free command-line way to invoke gRPC methods, inspect schemas, or work with streaming RPCs. If a server has no reflection, you will need its proto source files or a protoset file to provide the schema.