Class: A2A::Bindings::Rest

Inherits:
Object
  • Object
show all
Defined in:
lib/a2a/bindings/rest.rb

Overview

Rack middleware implementing the A2A HTTP+JSON/REST protocol binding.

Extracts the HTTP verb, path, and request body/params into env keys. Calls downstream. On return, wraps env into a REST response with content-type application/a2a+json.

Streaming operations: When the handler sets env to an SSE::Stream (which is a Protocol::HTTP::Body::Readable), Falcon streams it natively —no wrapping, no #each conversion, true async with backpressure.

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ Rest

Returns a new instance of Rest.



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# File 'lib/a2a/bindings/rest.rb', line 21

def initialize(app)
  @app = app
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/a2a/bindings/rest.rb', line 25

def call(env)
  req = Rack::Request.new(env)

  env["a2a.verb"] = req.request_method.downcase
  env["a2a.path"] = req.path_info

  params = {}
  if req.post? || req.put? || req.patch?
    begin
      params = JSON.parse(req.body.read) rescue {}
    end
  end

  # Merge query params for GET/DELETE
  params.merge!(req.params) if req.get? || req.delete?

  env["a2a.body"] = params

  @app.call(env)

  # Check if handler signalled a REST error
  if (err = env["a2a.error"])
    return error_response(err[:http_status] || 400, err[:message], err[:data])
  end

  # Check if handler set up a streaming response.
  # The stream is an SSE::Stream (Protocol::HTTP::Body::Readable).
  if (stream = env["a2a.stream"])
    return [200, A2A::SSE::Stream.headers, stream]
  end

  result = env["a2a.result"]
  success_response(result)
end