diff --git a/lib/recurly.rb b/lib/recurly.rb
index 6d653ebac..10d361356 100644
--- a/lib/recurly.rb
+++ b/lib/recurly.rb
@@ -10,6 +10,8 @@
 require "recurly/connection_pool"
 require "recurly/client"
 require "recurly/webhooks"
+require "recurly/config"
+require "recurly/models"
 
 module Recurly
   STRICT_MODE = ENV["RECURLY_STRICT_MODE"] && ENV["RECURLY_STRICT_MODE"].downcase == "true"
diff --git a/lib/recurly/config.rb b/lib/recurly/config.rb
new file mode 100644
index 000000000..d15ac9be8
--- /dev/null
+++ b/lib/recurly/config.rb
@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Configuration class for Recurly API client.
+  class Config
+    @@client = nil
+
+    def self.client=(val)
+      @@client = val
+    end
+
+    def self.api_key
+      ENV["RECURLY_API_KEY"]
+    end
+
+    def self.host
+      ENV["RECURLY_HOST"] || "v3.recurly.com"
+    end
+
+    def self.port
+      ENV["RECURLY_PORT"] || "443"
+    end
+
+    def self.region
+      ENV["RECURLY_REGION"]&.to_sym || :us
+    end
+
+    def self.debug?
+      ENV["RECURLY_DEBUG"].to_s.upcase == "TRUE"
+    end
+
+    def self.base_url
+      "https://#{host}:#{port}"
+    end
+
+    def self.ca_file
+      return unless host.end_with?(".recurly.dev")
+
+      @ca_file ||= begin
+          path = File.join(File.dirname(__FILE__), "../../../../", "certs/ca_root.crt")
+          File.exist?(path) ? path : (raise "CA file does not exist: #{path}")
+        end
+    end
+
+    def self.client
+      return @@client if @@client
+
+      opt = {
+        api_key: api_key,
+        logger: Logger.new(STDOUT).tap { |l| l.level = debug? ? Logger::DEBUG : Logger::INFO },
+        region: region,
+        base_url: base_url,
+      }
+      opt[:ca_file] = ca_file if ca_file
+      @client ||= Recurly::Client.new(**opt)
+    end
+  end
+end
diff --git a/lib/recurly/model.rb b/lib/recurly/model.rb
new file mode 100644
index 000000000..231e03363
--- /dev/null
+++ b/lib/recurly/model.rb
@@ -0,0 +1,92 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Base model class for Recurly ORM Interface.
+  class Model
+    API_KEYS = %i[ids limit sort order begin_time end_time].freeze
+    attr_accessor :resource
+
+    def initialize(res)
+      @resource = res
+    end
+
+    def self.client
+      cli = Config.client
+      raise "API client is not configured" unless cli
+
+      cli
+    end
+
+    def self.api_keys
+      API_KEYS
+    end
+
+    # Lookup methods which should be implemented in subclasses.
+    def self.list(params)
+      raise NotImplementedError, "The list method should be implemented in the subclass."
+    end
+
+    def self.get(id:)
+      raise NotImplementedError, "The get method should be implemented in the subclass."
+    end
+
+    # Lookup methods
+    def self.all
+      where
+    end
+
+    def self.where(query = query_params, *args)
+      if query.is_a?(String)
+        conditions = QueryParser.parse(query, *args)
+        api_params = {}
+        filter_params = []
+        conditions.each do |cond|
+          val = cond[:value].respond_to?(:iso8601) ? cond[:value].iso8601 : cond[:value]
+          if api_keys.include?(cond[:key].to_sym)
+            api_params[cond[:key].to_sym] = val
+          else
+            filter_params << cond.merge(value: val)
+          end
+        end
+        pager = list(params: api_params)
+        ModelPager.new(model_class: self, pager: pager, filters: filter_params)
+      else
+        api_params = (query || {}).select { |k, _| api_keys.include?(k) }
+        pager = list(params: api_params)
+        ModelPager.new(model_class: self, pager: pager)
+      end
+    end
+
+    def self.find_by(args = {})
+      args[:id] ? new(get(id: args[:id])) : nil
+    rescue Recurly::Errors::NotFoundError
+      nil
+    end
+
+    # Default query parameters for listing or searching models.
+    def self.query_params(args = nil)
+      params = { limit: 200 }
+      if args
+        params[:limit] = args[:limit] if args[:limit]
+        params[:sort] = args[:sort] if args[:sort]
+        params[:order] = args[:order] if args[:order]
+        params[:begin_time] = args[:begin_time].iso8601 if args[:begin_time]
+        params[:end_time] = args[:end_time].iso8601 if args[:end_time]
+      end
+      params
+    end
+
+    # Method delegation to the resource for all methods not defined in this or child classes.
+    def method_missing(method, *args, &block)
+      if @resource.respond_to?(method)
+        @resource.public_send(method, *args, &block)
+      else
+        super
+      end
+    end
+
+    def respond_to_missing?(method, include_private = false)
+      @resource.respond_to?(method, include_private) || super
+    end
+  end
+end
diff --git a/lib/recurly/model_filter.rb b/lib/recurly/model_filter.rb
new file mode 100644
index 000000000..6fdbc9595
--- /dev/null
+++ b/lib/recurly/model_filter.rb
@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Handles filtering logic for ModelPager
+  class ModelFilter
+    def initialize(filters)
+      @filters = filters
+    end
+
+    def include?(model)
+      return true if @filters.nil? || @filters.empty?
+
+      @filters.all? do |cond|
+        val = cond[:key].match(/\./) ? dig_value(model, cond[:key]) : model.public_send(cond[:key])
+        cmp_val = cond[:value]
+
+        val_parsed = try_parse(val)
+        cmp_parsed = try_parse(cmp_val)
+
+        case cond[:op]
+        when "="
+          val_parsed == cmp_parsed
+        when "!="
+          val_parsed != cmp_parsed
+        when ">", ">=", "<", "<="
+          return false if val_parsed.nil? || cmp_parsed.nil?
+
+          case cond[:op]
+          when ">"
+            val_parsed > cmp_parsed
+          when ">="
+            val_parsed >= cmp_parsed
+          when "<"
+            val_parsed < cmp_parsed
+          when "<="
+            val_parsed <= cmp_parsed
+          end
+        else
+          false
+        end
+      end
+    end
+
+    private
+
+    # Recursively dig through nested attributes and arrays
+    def dig_value(obj, key_chain)
+      keys = key_chain.to_s.split(".")
+      current = obj
+      keys.each do |key|
+        if current.is_a?(Array)
+          current = current.map { |el| dig_value(el, key) }.flatten.compact
+        elsif current.respond_to?(key)
+          current = current.public_send(key)
+        else
+          return nil
+        end
+      end
+      current.is_a?(Array) && current.size == 1 ? current.first : current
+    end
+
+    def try_parse(value)
+      begin
+        return DateTime.parse(value) if value.is_a?(String)
+      rescue ArgumentError;       end
+      begin
+        return Integer(value) if value.to_s.match(/\A-?\d+\z/)
+      rescue ArgumentError, TypeError;       end
+      begin
+        return Float(value) if value.to_s.match(/\A-?\d+(\.\d+)?\z/)
+      rescue ArgumentError, TypeError;       end
+      value
+    end
+  end
+end
diff --git a/lib/recurly/model_pager.rb b/lib/recurly/model_pager.rb
new file mode 100644
index 000000000..104c6344f
--- /dev/null
+++ b/lib/recurly/model_pager.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Pager extension for Recurly ORM Interface models, allowing iteration over model instances.
+  class ModelPager < Pager
+    include Enumerable
+
+    def initialize(model_class:, pager:, filters: [])
+      @model_class = model_class
+      @filter = ModelFilter.new(filters)
+      super(client: pager.client, path: pager.next, options: pager.instance_variable_get(:@options))
+    end
+
+    def each(&block)
+      super do |item|
+        model = @model_class.new(item)
+        block.call(model) if @filter.include?(model)
+      end
+    end
+
+    def each_page(&block)
+      super do |page|
+        transformed_page = page.each_with_object([]) do |item, result|
+          model = @model_class.new(item)
+          result << model if @filter.include?(model)
+        end
+        block.call(transformed_page) if block_given?
+      end
+    end
+  end
+end
diff --git a/lib/recurly/models.rb b/lib/recurly/models.rb
new file mode 100644
index 000000000..47dbee21f
--- /dev/null
+++ b/lib/recurly/models.rb
@@ -0,0 +1,7 @@
+require_relative "query_parser"
+require_relative "model_pager"
+require_relative "model_filter"
+require_relative "model"
+Dir[File.join(__dir__, "models", "*.rb")].each do |file|
+  require file unless file.end_with?("model.rb")
+end
diff --git a/lib/recurly/models/account.rb b/lib/recurly/models/account.rb
new file mode 100644
index 000000000..2838d4d6c
--- /dev/null
+++ b/lib/recurly/models/account.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents an Account in Recurly
+  class Account < Recurly::Model
+    def self.list(params:)
+      p "Listing accounts with params: #{params.inspect}"
+      client.list_accounts(params: params)
+    end
+
+    def self.get(id:)
+      client.get_account(account_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/add_on.rb b/lib/recurly/models/add_on.rb
new file mode 100644
index 000000000..a1dee2eff
--- /dev/null
+++ b/lib/recurly/models/add_on.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a AddOn in Recurly
+  class AddOn < Recurly::Model
+    def self.list(params:)
+      client.list_add_ons(params: params)
+    end
+
+    def self.get(id:)
+      client.get_add_on(add_on_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/business_entity.rb b/lib/recurly/models/business_entity.rb
new file mode 100644
index 000000000..5f9a7562e
--- /dev/null
+++ b/lib/recurly/models/business_entity.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a BusinessEntity in Recurly
+  class BusinessEntity < Recurly::Model
+    def self.list(params:)
+      client.list_business_entities(params: params)
+    end
+
+    def self.get(id:)
+      client.get_business_entity(business_entity_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/coupon.rb b/lib/recurly/models/coupon.rb
new file mode 100644
index 000000000..5228bb12a
--- /dev/null
+++ b/lib/recurly/models/coupon.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a Coupon in Recurly
+  class Coupon < Recurly::Model
+    def self.list(params:)
+      client.list_coupons(params: params)
+    end
+
+    def self.get(id:)
+      client.get_coupon(coupon_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/dunning_campaign.rb b/lib/recurly/models/dunning_campaign.rb
new file mode 100644
index 000000000..cc0bc14fe
--- /dev/null
+++ b/lib/recurly/models/dunning_campaign.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a DunningCampaign in Recurly
+  class DunningCampaign < Recurly::Model
+    def self.list(params:)
+      client.list_dunning_campaigns(params: params)
+    end
+
+    def self.get(id:)
+      client.get_dunning_campaign(dunning_campaign_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/external_invoice.rb b/lib/recurly/models/external_invoice.rb
new file mode 100644
index 000000000..b6410a0fe
--- /dev/null
+++ b/lib/recurly/models/external_invoice.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a ExternalInvoice in Recurly
+  class ExternalInvoice < Recurly::Model
+    def self.list(params:)
+      client.list_external_invoices(params: params)
+    end
+
+    def self.get(id:)
+      client.show_external_invoice(external_invoice_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/external_product.rb b/lib/recurly/models/external_product.rb
new file mode 100644
index 000000000..cb73802c7
--- /dev/null
+++ b/lib/recurly/models/external_product.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a ExternalProduct in Recurly
+  class ExternalProduct < Recurly::Model
+    def self.list(params:)
+      client.list_external_products(params: params)
+    end
+
+    def self.get(id:)
+      client.get_external_product(external_product_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/external_subscription.rb b/lib/recurly/models/external_subscription.rb
new file mode 100644
index 000000000..12e6577b4
--- /dev/null
+++ b/lib/recurly/models/external_subscription.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a ExternalSubscription in Recurly
+  class ExternalSubscription < Recurly::Model
+    def self.list(params:)
+      client.list_external_subscriptions(params: params)
+    end
+
+    def self.get(id:)
+      client.get_external_subscription(external_subscription_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/general_ledger_account.rb b/lib/recurly/models/general_ledger_account.rb
new file mode 100644
index 000000000..37e3452fc
--- /dev/null
+++ b/lib/recurly/models/general_ledger_account.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a GeneralLedgerAccount in Recurly
+  class GeneralLedgerAccount < Recurly::Model
+    def self.list(params:)
+      client.list_general_ledger_accounts(params: params)
+    end
+
+    def self.get(id:)
+      client.get_general_ledger_account(general_ledger_account_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/gift_card.rb b/lib/recurly/models/gift_card.rb
new file mode 100644
index 000000000..abb5002ee
--- /dev/null
+++ b/lib/recurly/models/gift_card.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a GiftCard in Recurly
+  class GiftCard < Recurly::Model
+    def self.list(params:)
+      client.list_gift_cards(params: params)
+    end
+
+    def self.get(id:)
+      client.get_gift_card(gift_card_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/invoice.rb b/lib/recurly/models/invoice.rb
new file mode 100644
index 000000000..19cd39737
--- /dev/null
+++ b/lib/recurly/models/invoice.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a Invoice in Recurly
+  class Invoice < Recurly::Model
+    def self.list(params:)
+      client.list_invoices(params: params)
+    end
+
+    def self.get(id:)
+      client.get_invoice(invoice_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/item.rb b/lib/recurly/models/item.rb
new file mode 100644
index 000000000..85133bb67
--- /dev/null
+++ b/lib/recurly/models/item.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a Item in Recurly
+  class Item < Recurly::Model
+    def self.list(params:)
+      client.list_items(params: params)
+    end
+
+    def self.get(id:)
+      client.get_item(item_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/line_item.rb b/lib/recurly/models/line_item.rb
new file mode 100644
index 000000000..ba5e396fe
--- /dev/null
+++ b/lib/recurly/models/line_item.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a LineItem in Recurly
+  class LineItem < Recurly::Model
+    def self.list(params:)
+      client.list_line_items(params: params)
+    end
+
+    def self.get(id:)
+      client.get_line_item(line_item_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/measured_unit.rb b/lib/recurly/models/measured_unit.rb
new file mode 100644
index 000000000..45140647c
--- /dev/null
+++ b/lib/recurly/models/measured_unit.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a MeasuredUnit in Recurly
+  class MeasuredUnit < Recurly::Model
+    def self.list(params:)
+      client.list_measured_unit(params: params)
+    end
+
+    def self.get(id:)
+      client.get_measured_unit(measured_unit_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/performance_obligation.rb b/lib/recurly/models/performance_obligation.rb
new file mode 100644
index 000000000..9efd26833
--- /dev/null
+++ b/lib/recurly/models/performance_obligation.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a PerformanceObligation in Recurly
+  class PerformanceObligation < Recurly::Model
+    def self.list(params:)
+      client.get_performance_obligations(params: params)
+    end
+
+    def self.get(id:)
+      client.get_performance_obligation(performance_obligation_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/plan.rb b/lib/recurly/models/plan.rb
new file mode 100644
index 000000000..bb3a07f21
--- /dev/null
+++ b/lib/recurly/models/plan.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a Plan in Recurly
+  class Plan < Recurly::Model
+    def self.list(params:)
+      client.list_plans(params: params)
+    end
+
+    def self.get(id:)
+      client.get_plan(plan_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/shipping_method.rb b/lib/recurly/models/shipping_method.rb
new file mode 100644
index 000000000..24d5a4ec5
--- /dev/null
+++ b/lib/recurly/models/shipping_method.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a ShippingMethod in Recurly
+  class ShippingMethod < Recurly::Model
+    def self.list(params:)
+      client.list_shipping_methods(params: params)
+    end
+
+    def self.get(id:)
+      client.get_shipping_method(shipping_method_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/site.rb b/lib/recurly/models/site.rb
new file mode 100644
index 000000000..863244c8b
--- /dev/null
+++ b/lib/recurly/models/site.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a Site in Recurly
+  class Site < Recurly::Model
+    def self.list(params:)
+      client.list_sites(params: params)
+    end
+
+    def self.get(id:)
+      client.get_site(site_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/subscription.rb b/lib/recurly/models/subscription.rb
new file mode 100644
index 000000000..06af0ff15
--- /dev/null
+++ b/lib/recurly/models/subscription.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a Subscription in Recurly
+  class Subscription < Recurly::Model
+    def self.api_keys
+      API_KEYS + %i[account_id]
+    end
+
+    def self.list(params:)
+      return client.list_account_subscriptions(account_id: params[:account_id]) if params.key?(:account_id)
+
+      client.list_subscriptions(params: params)
+    end
+
+    def self.get(id:)
+      client.get_subscription(subscription_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/models/transaction.rb b/lib/recurly/models/transaction.rb
new file mode 100644
index 000000000..423a57d85
--- /dev/null
+++ b/lib/recurly/models/transaction.rb
@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module Recurly
+  # Represents a Transaction in Recurly
+  class Transaction < Recurly::Model
+    def self.list(params:)
+      client.list_transactions(params: params)
+    end
+
+    def self.get(id:)
+      client.get_transaction(transaction_id: id)
+    end
+  end
+end
diff --git a/lib/recurly/query_parser.rb b/lib/recurly/query_parser.rb
new file mode 100644
index 000000000..819c0af71
--- /dev/null
+++ b/lib/recurly/query_parser.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Recurly
+  class QueryParser
+    # Parses a SQL-like query string and arguments into a hash of conditions.
+    # Example: "order = ? AND sort = ? AND state != ?", 'desc', 'updated_at', 'inactive'
+    def self.parse(query, *args)
+      conditions = []
+      arg_index = 0
+      raise ArgumentError, "Input too long" if query.length > 1000
+
+      reg = /([a-zA-Z_][\w\.]*)\s*(=|!=|>=|<=|>|<)\s*(\?|'(?:[^']*)'|"(?:[^"]*)"|-?\d+(?:\.\d+)?|\w+)/i
+      query.scan(reg).each do |key, op, val, _|
+        if val == "?"
+          value = args[arg_index]
+          arg_index += 1
+        else
+          # Remove quotes if present
+          value = val.gsub(/\A['"]|['"]\z/, "")
+          # Convert numeric strings to numbers
+          if value.match(/\A-?\d+\z/)
+            value = value.to_i
+          elsif value.match(/\A-?\d+\.\d+\z/)
+            value = value.to_f
+          end
+        end
+        conditions << { key: key, op: op, value: value }
+      end
+
+      conditions
+    end
+  end
+end