Clamo

JSON-RPC protocol toolkit for Ruby.

Consume, Serve or test JSON-RPC endpoints with Clamo.

Installation

Install the gem and add to the application's Gemfile by executing:

$ bundle add clamo

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install clamo

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machi# Clamo

A Ruby implementation of JSON-RPC 2.0 designed for simplicity and compliance with the specification.

Usage

Basic Usage

require 'clamo'

# Define a service object with methods you want to expose
module MyService
  def self.add(a, b)
    a + b
  end
  
  def self.subtract(a:, b:)
    a - b
  end
  
  # Private methods won't be accessible via JSON-RPC
  private_class_method def self.internal_method
    # This won't be exposed
  end
end

# Handle a JSON-RPC request
request_body = '{"jsonrpc": "2.0", "method": "add", "params": [1, 2], "id": 1}'
response = Clamo::Server.unparsed_dispatch_to_object(
  request: request_body,
  object: MyService
)

puts response
# => {"jsonrpc":"2.0","result":3,"id":1}

Handling Different Parameter Types

Clamo supports both positional (array) and named (object/hash) parameters:

# Positional parameters
request = '{"jsonrpc": "2.0", "method": "add", "params": [1, 2], "id": 1}'

# Named parameters
request = '{"jsonrpc": "2.0", "method": "subtract", "params": {"a": 5, "b": 3}, "id": 2}'

Batch Requests

Clamo handles batch requests automatically:

batch_request = <<~JSON
[
  {"jsonrpc": "2.0", "method": "add", "params": [1, 2], "id": 1},
  {"jsonrpc": "2.0", "method": "subtract", "params": {"a": 5, "b": 3}, "id": 2}
]
JSON

batch_response = Clamo::Server.unparsed_dispatch_to_object(
  request: batch_request,
  object: MyService
)

puts batch_response
# => [{"jsonrpc":"2.0","result":3,"id":1},{"jsonrpc":"2.0","result":2,"id":2}]

Notifications

Notifications are requests without an ID field. They don't produce a response:

notification = '{"jsonrpc": "2.0", "method": "add", "params": [1, 2]}'
response = Clamo::Server.unparsed_dispatch_to_object(
  request: notification,
  object: MyService
)

puts response
# => nil

Building JSON-RPC Requests

Clamo provides utilities for building JSON-RPC requests:

request = Clamo::JSONRPC.build_request(
  method: "add",
  params: [1, 2],
  id: 1
)

puts request
# => {:jsonrpc=>"2.0", :method=>"add", :params=>[1, 2], :id=>1}

Error Handling

Clamo follows the JSON-RPC 2.0 specification for error handling:

Error Code	Message	Description
-32700	Parse error	Invalid JSON was received
-32600	Invalid request	The JSON sent is not a valid Request object
-32601	Method not found	The method does not exist / is not available
-32602	Invalid params	Invalid method parameter(s)
-32603	Internal error	Internal JSON-RPC error
-32000	Server error	Reserved for implementation-defined server errors

Advanced Features

Parallel Processing

Batch requests are processed in parallel using the parallel gem. You can pass options to Parallel.map via the parsed_dispatch_to_object method:

Clamo::Server.parsed_dispatch_to_object(
  request: batch_request,
  object: MyService,
  in_processes: 4  # Parallel processing option
)

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/rubakas/clamo.

License

The gem is available as open source under the terms of the MIT License.ne, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/rubakas/clamo