class LittleGhost::MCP::SigV4Signer

SigV4Signer adds AWS Signature Version 4 authentication to MCP requests. Requires the application-provided aws-sigv4 gem and uses its normal AWS credentials-provider chain unless one is supplied explicitly.

Public Class Methods

new (service:, region:, credentials_provider: nil)

Source

# File lib/little_ghost/mcp/client.rb, line 373
def initialize(service:, region:, credentials_provider: nil)
  require "aws-sigv4"
  @signer = Aws::Sigv4::Signer.new(
    service: service,
    region: region,
    credentials_provider: credentials_provider
  )
rescue LoadError
  raise ConfigurationError, "MCP SigV4 signing requires the optional aws-sigv4 gem"
end

Configures signing for service and region.

Public Instance Methods

call (request)

Source

# File lib/little_ghost/mcp/client.rb, line 385
def call(request)
  signature = @signer.sign_request(
    http_method: request.method,
    url: request.uri,
    headers: request.to_hash.transform_values { |values| Array(values).join(",") },
    body: request.body
  )
  signature.headers.each { |name, value| request[name] = value }
end

Signs request in place immediately before transport.