fauxrpc curl

The fauxrpc curl command is a powerful, built-in client for sending requests with dynamically generated fake data to any gRPC, gRPC-Web, or ConnectRPC service. It’s the perfect tool for quickly testing endpoints, running smoke tests, or debugging services without needing to write a dedicated client.

It can use a schema source (like a Protobuf file or a Buf Schema Registry URL) or server reflection to automatically understand the service’s API and generate valid requests.

Flags

Usage: fauxrpc curl [<method>] [flags]

Make requests with fake data

Arguments:
  [<method>]    Service or method name.

Flags:
  -h, --help                            Show context-sensitive help.
  -l, --log-level="info"                Set the logging level (debug|info|warn|error)
      --version                         Print version information and quit

      --schema=SCHEMA,...               RPC schema modules.
  -a, --addr="http://127.0.0.1:6660"    Address to make a request to
  -p, --protocol="grpc"                 Protocol to use for requests.
  -e, --encoding="proto"                Encoding to use for requests.
      --http2-prior-knowledge           This flag can be used to indicate that HTTP/2 should be used.
      --http-3                          Enables HTTP/3.

Here is a comprehensive list of all the flags available for the fauxrpc curl command.

Flag	Default	Description
Target & Schema
`[<method>]`	`(none)`	The target service or method name to call (e.g., `my.service.v1.UserService/GetUser`). If omitted, `fauxrpc curl` will attempt to call all methods in the schema.
`--schema=...`	`(none)`	📜 Specifies the source for the RPC schema. It can be a local file path, a directory, or a URL. If not provided, the command will rely on server reflection.
`-a, --addr`	`http://127.0.0.1:6660`	The full address of the server to send the request to.
Protocol & Encoding
`-p, --protocol`	`grpc`	The protocol to use for the request. Valid options are `grpc`, `grpc-web`, and `connect`.
`-e, --encoding`	`proto`	The encoding to use for the request payload. Valid options are `proto` and `json`.
`--http2-prior-knowledge`	`false`	Use this flag to connect to a gRPC server that does not use TLS, indicating that the client should use HTTP/2 directly without an initial HTTP/1.1 upgrade request.
`--http-3`	`false`	Enables experimental HTTP/3 support for the request.
General
`-l, --log-level`	`info`	Sets the logging verbosity. Available levels are `debug`, `info`, `warn`, and `error`.
`--version`	`false`	Prints the current `fauxrpc` version information and then exits.
`-h, --help`	`false`	Shows a summary of the command and its flags.

Practical Examples

1. Test All Methods in a Service

This command uses a remote schema from the Buf Schema Registry to discover all available RPCs and sends a request with fake data to each one. This is a great way to perform a quick smoke test on an entire service.

fauxrpc curl \
  --http2-prior-knowledge \
  --schema=buf.build/bufbuild/registry

Call a Specific RPC Method

To target a single method, simply provide its fully qualified name as an argument after the flags.

fauxrpc curl \
  --http2-prior-knowledge \
  --schema=buf.build/bufbuild/registry \
  buf.registry.plugin.v1beta1.LabelService/ListLabels

Use Server Reflection

If the target server has reflection enabled, you don’t need to provide a –schema. fauxrpc curl will automatically query the server to determine how to construct the request.

# Assuming the server at the default address has reflection enabled
fauxrpc curl \
  --http2-prior-knowledge \
  buf.registry.plugin.v1beta1.LabelService/ListLabels

Target a gRPC-Web Service

You can easily switch protocols to test different server implementations, like a gRPC-Web service that uses JSON encoding.

fauxrpc curl \
  --addr=http://localhost:8080 \
  --protocol=grpc-web \
  --encoding=json \
  my.webapp.v1.AuthService/Login

Inputs fauxrpc generate