diff --git a/app/lib/atomic_lti/authorization.rb b/app/lib/atomic_lti/authorization.rb
index 1c4e509..1efa0bf 100644
--- a/app/lib/atomic_lti/authorization.rb
+++ b/app/lib/atomic_lti/authorization.rb
@@ -62,7 +62,7 @@ def self.client_assertion(iss:, deployment_id:)
       raise AtomicLti::Exceptions::NoLTIPlatform.new(iss: iss, deployment_id: deployment_id) if platform.nil?
 
       payload = {
-        iss:  install.client_id,  # A unique identifier for the entity that issued the JWT
+        iss: install.client_id,  # A unique identifier for the entity that issued the JWT
         sub: install.client_id, # "client_id" of the OAuth Client
         aud: platform.token_url, # Authorization server identifier
         iat: Time.now.to_i, # Timestamp for when the JWT was created
diff --git a/app/lib/atomic_lti/definitions.rb b/app/lib/atomic_lti/definitions.rb
index b94ddd0..a7f2565 100644
--- a/app/lib/atomic_lti/definitions.rb
+++ b/app/lib/atomic_lti/definitions.rb
@@ -25,9 +25,9 @@ class Definitions
     DEEP_LINKING_DATA_CLAIM = "https://purl.imsglobal.org/spec/lti-dl/claim/data".freeze
     DEEP_LINKING_TOOL_MSG_CLAIM = "https://purl.imsglobal.org/spec/lti-dl/claim/msg".freeze
     DEEP_LINKING_TOOL_LOG_CLAIM = "https://purl.imsglobal.org/spec/lti-dl/claim/log".freeze
+    DEEP_LINKING_SERVICE_CLAIM = "https://purl.imsglobal.org/spec/lti-dl/claim/deeplinkingservice".freeze
     CONTENT_ITEM_CLAIM = "https://purl.imsglobal.org/spec/lti-dl/claim/content_items".freeze
     NAMES_AND_ROLES_CLAIM = "https://purl.imsglobal.org/spec/lti-nrps/claim/namesroleservice".freeze
-
     NAMES_AND_ROLES_SERVICE_VERSIONS = ["2.0"].freeze
 
     CALIPER_CLAIM = "https://purl.imsglobal.org/spec/lti-ces/claim/caliper-endpoint-service".freeze
@@ -43,6 +43,11 @@ class Definitions
     NAMES_AND_ROLES_SCOPE = "https://purl.imsglobal.org/spec/lti-nrps/scope/contextmembership.readonly".freeze
     CALIPER_SCOPE = "https://purl.imsglobal.org/spec/lti-ces/v1p0/scope/send".freeze
 
+    DEEP_LINKING_READ = "https://purl.imsglobal.org/spec/lti-dl/scope/contentitem.read".freeze
+    DEEP_LINKING_UPDATE = "https://purl.imsglobal.org/spec/lti-dl/scope/contentitem.update".freeze
+    DEEP_LINKING_ADD = "https://purl.imsglobal.org/spec/lti-dl/scope/contentitem.add".freeze
+    DEEP_LINKING_DELETE = "https://purl.imsglobal.org/spec/lti-dl/scope/contentitem.delete".freeze
+
     STUDENT_SCOPE = "http://purl.imsglobal.org/vocab/lis/v2/institution/person#Student".freeze
     INSTRUCTOR_SCOPE = "http://purl.imsglobal.org/vocab/lis/v2/institution/person#Instructor".freeze
     LEARNER_SCOPE = "http://purl.imsglobal.org/vocab/lis/v2/membership#Learner".freeze
diff --git a/app/lib/atomic_lti/services/deep_linking.rb b/app/lib/atomic_lti/services/deep_linking.rb
new file mode 100644
index 0000000..2926bdc
--- /dev/null
+++ b/app/lib/atomic_lti/services/deep_linking.rb
@@ -0,0 +1,121 @@
+# Implemenation of
+# https://github.com/1EdTech/LTI-central/blob/main/proposals/deeplinking-service/specification.md#deep-linking-rest-service-1
+module AtomicLti
+  module Services
+    class DeepLinking < AtomicLti::Services::Base
+
+      def initialize(id_token_decoded:)
+        super(id_token_decoded: id_token_decoded)
+      end
+
+      def scopes
+        @id_token_decoded&.dig(AtomicLti::Definitions::DEEP_LINKING_SERVICE_CLAIM, "scopes")
+      end
+
+      def content_items_endpoint
+        url = @id_token_decoded.dig(AtomicLti::Definitions::DEEP_LINKING_SERVICE_CLAIM, "contentitems")
+        raise AtomicLti::Exceptions::DEEP_LINKING_SERVICE_CLAIM, "Unable to access content items url" if url.blank?
+
+        url
+      end
+
+      def content_item_endpoint
+        url = @id_token_decoded.dig(AtomicLti::Definitions::DEEP_LINKING_SERVICE_CLAIM, "contentitem")
+        raise AtomicLti::Exceptions::DEEP_LINKING_SERVICE_CLAIM, "Unable to access content item url" if url.blank?
+
+        url
+      end
+
+      # Allows a tool to get a list of all items linked to the tool in a given context.
+      # Parameters:
+      #   query may include:
+      #     limit: Specifies the maximum number of results to return. The platform may return fewer results.
+      #     rlid: Filters results to the specified resource link id.
+      #       See: https://github.com/1EdTech/LTI-central/blob/main/proposals/deeplinking-service/specification.md#filter-by-resourcelinkid
+      # Returns:
+      #  An array of items as JSON.
+      # Example:
+      #   "items": [
+      #     {
+      #       "readonly": ["available", "resourceLinkId", "id"],
+      #       "id": "https://www.myuniv.example.com/2344/content_items/389a-5478-78fg",
+      #       "type": "ltiResourceLink",
+      #       "resourceLinkId": "389a-5478-78fg",
+      #       "title": "A title",
+      #       "text": "This is a link to an activity that will be graded",
+      #       "url": "https://lti.example.com/launchMe",
+      #       "icon": {
+      #         "url": "https://lti.example.com/image.jpg",
+      #         "width": 100,
+      #         "height": 100
+      #       },
+      #       "thumbnail": {
+      #         "url": "https://lti.example.com/thumb.jpg",
+      #         "width": 90,
+      #         "height": 90
+      #       },
+      #       "lineItemId": "https://www.myuniv.example.com/2344/lineitems/345991",
+      #       "available": {
+      #         "startDateTime": "2024-02-06T20:05:02Z",
+      #         "endDateTime": "2024-03-07T20:05:02Z"
+      #       },
+      #       "submission": {
+      #         "endDateTime": "2024-03-06T20:05:02Z"
+      #       },
+      #       "custom": {
+      #         "quiz_id": "az-123",
+      #         "duedate": "$Resource.submission.endDateTime"
+      #       }
+      #     }
+      #   ]
+      # }
+      def list(query = {})
+        accept = { "Accept" => "application/vnd.1edtech.lti.contentitems+json" }
+        HTTParty.get(content_items_endpoint, headers: headers(accept), query: query)
+      end
+
+      # Updates the content item
+      #
+      # Parameters:
+      #   content_item_url: The url of the content item to update
+      #   content_item: The content item to update
+      #     The id, lineItemId, resourceLinkId and type properties are inherently read-only.
+      #
+      # Example content_item:
+      # {
+      #   "id": "https://www.myuniv.example.com/2344/content_items/389a-5478-4712",
+      #   "type": "ltiResourceLink",
+      #   "resourceLinkId": "389a-5478-4712",
+      #   "title": "The ghost of the republic updated",
+      #   "text": "This is a link to a video resource",
+      #   "url": "https://lti.example.com/launchMe",
+      #   "custom": {
+      #     "video_id": "89042-ejxl01-updated",
+      #   }
+      #   "available": {
+      #     "startDateTime": "2024-02-06T20:05:02Z",
+      #     "endDateTime": "2024-03-11T22:00:00Z"
+      #   },
+      #   "submission": {
+      #     "endDateTime": "2024-03-08T22:00:00Z"
+      #   }
+      # }
+      #
+      # Returns:
+      #  The updated content item as JSON.
+      def update(content_item_url, content_item)
+        accept = { "Accept" => "application/vnd.1edtech.lti.contentitem+json" }
+        HTTParty.put(content_item_url, headers: headers(accept), body: content_item.to_json)
+      end
+
+      # Adds a new content item. This is an optional method since platforms are not required to support an add endpoint.
+      # Check for platform support before calling add.
+      # If a line item was requested, and the platform created it, the lineItemId must be included in the response.
+      def add(content_item)
+        accept = { "Accept" => "application/vnd.1edtech.lti.contentitem+json" }
+        HTTParty.post(content_items_endpoint, headers: headers(accept), body: content_item.to_json)
+      end
+
+    end
+  end
+end