grpcui vs grpcurl: which one should I use?

Use grpcui for visual, interactive testing via a web UI, ideal for debugging and exploration. Choose grpcurl for command-line scripting, automation, or incremental streaming interactions where real-time control is needed.

How to use grpcui with a server that doesn't have reflection?

Provide proto source files using the -proto flag or compiled protoset files created with protoc. You may also need -import-path flags to specify dependency locations, as explained in the README.

Does grpcui support bidirectional streaming?

Yes, it supports bidirectional streaming methods, but you must define all request messages in the stream at once and receive all responses at once, which limits interactive testing compared to CLI tools.

Can I embed grpcui in my own Go application?

Yes, grpcui provides library packages for embedding the web UI into Go HTTP servers. The standalone package offers a simple HTTP handler for easy integration, as detailed in the README.

How to handle TLS or mutual TLS with grpcui?

Use command-line flags like -tls, -tls-ca-cert, and -tls-client-cert to configure secure connections. The tool supports plain-text, TLS, and mutual TLS setups, with options documented in the -help output.

What are the limitations for automated testing with grpcui?

grpcui is not easily scriptable for CI/CD pipelines due to its web-based nature. For automation, consider using grpcurl or programmatic gRPC clients that offer better integration with testing frameworks.

Open-Awesome

gRPC UI

MITJavaScriptv1.5.4

A command-line tool that provides an interactive web UI for testing and debugging gRPC servers, similar to Postman for gRPC APIs.

GitHub

5.9k stars427 forks0 contributors

What is gRPC UI?

grpcui is a command-line tool that launches an interactive web UI for testing and debugging gRPC servers. It allows developers to browse service schemas, construct and send requests, and view responses through a browser-based interface, similar to how Postman works for REST APIs. It solves the problem of cumbersome gRPC API testing by providing a visual, intuitive alternative to command-line tools.

Target Audience

Developers and engineers working with gRPC-based microservices who need to test, debug, or explore APIs without writing custom client code. It's particularly useful for backend developers, API designers, and QA engineers involved in gRPC service development.

Value Proposition

Developers choose grpcui because it combines the power of gRPC with the convenience of a web-based GUI, offering real-time interaction, schema discovery via reflection, and support for complex protobuf types. Its seamless integration with existing gRPC ecosystems and ability to handle streaming methods make it a versatile tool for API exploration.

Overview

An interactive web UI for gRPC, along the lines of postman

Use Cases

Best For

Testing gRPC APIs interactively without writing client code
Debugging gRPC services by inspecting request/response payloads
Exploring gRPC service schemas via server reflection
Demonstrating gRPC API functionality to team members or stakeholders
Quickly prototyping gRPC requests with JSON input
Validating protobuf message structures and data formats

Not Ideal For

Real-time, incremental bidirectional streaming testing where messages need to be sent and received interactively
Headless or CLI-only environments without browser access, such as remote servers or automated scripts
Automated testing pipelines that require programmatic, scriptable interfaces for CI/CD integration
Servers that lack gRPC reflection and where proto files are unavailable or difficult to manage

Pros & Cons

Pros

Dynamic Form Generation

Automatically creates HTML forms for protobuf messages, including nested structures, one-ofs, and repeated fields, making complex data entry intuitive without manual JSON crafting.

Server Reflection Support

Discovers service schemas automatically from servers supporting gRPC reflection, eliminating the need for manual proto file handling in many cases, as noted in the README.

Rich Type Handling

Provides specialized UI elements for well-known protobuf types like Timestamp (date picker) and StringValue (textbox), enhancing usability beyond raw JSON input.

Multiple Descriptor Sources

Works with proto source files, compiled protoset files, or server reflection, offering flexibility in schema provision without locking into a single method.

Cons

Limited Streaming Interactivity

Requires constructing entire request streams at once and displays all responses at once, unlike tools like grpcurl that allow incremental, real-time interaction with bidirectional streams.

Dependency on Reflection or Files

If the server doesn't support reflection and proto files aren't provided, setup becomes cumbersome and manual, adding overhead for exploration or debugging.

Web-Based Limitation

As a browser-dependent tool, it's unsuitable for headless environments or scenarios where command-line scripting is preferred, limiting integration into automated workflows.

Open Source Alternative To

gRPC UI is an open-source alternative to the following products:

Postman

Postman is a collaboration platform for API development that allows developers to design, test, and document APIs.

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