diff --git a/README.md b/README.md
index 67f14e4..88e94b8 100644
--- a/README.md
+++ b/README.md
@@ -309,6 +309,28 @@ curl -v -H $'Authorization: Bearer <AccessToken>' -H 'AuthorizationContext: <Aut
 }" <local/staging test url>/api/v1/route
 ```
 
+### Acknowledgement API
+
+Example request to acknowledge delivery / read of messages sent from agent. Be sure to replace placeholder values `<..>`
+
+```bash
+curl -v -H $'Authorization: Bearer <AccessToken>' -H 'AuthorizationContext: <AuthorizationContext>' -H 'RequestId: <RequestId>' -H 'OrgId: <OrgId>' -H 'Content-Type: application/json' -X POST -d "{
+    \"sender\": {
+      \"appType\" : \"<AppType>\",
+      \"subject\" : \"<endUserClientId>\",
+      \"role\" : \"<ParticipantRole>\"
+    },
+    \"conversationIdentifier\" : \"<conversation Identifier>\",
+    \"acknowledgements\" : [ {
+      \"acknowledgementTimestamp\" : <Timestamp in Unix Epoch>,
+      \"acknowledgementType\" : \"<Acknowledgement Type>\",
+      \"acknowledgedConversationEntryIdentifier\" : \"<Acknowledged Conversation Entry Identifier>\",
+      \"acknowledgmentCreatedConversationEntryIdentifier\" : \"<Acknowledgment Created Conversation Entry Identifier>\"
+    }, {..}, {..} . . . {..}]
+}" <local/staging test url>/api/v1/acknowledgement
+```
+Note: Only maximum of 25 acknowledgments are supported per request
+
 ## outbound-custom-event-payload.yaml
 The [outbound-custom-event-payload.yaml](outbound-custom-event-payload.yaml) shows the outbound message custom event schema. Following are examples of the custom event payload received in "data" listener of the custome event after subscribe the event by topic name "my__event__e" shown in payload below for outbound message.
 
diff --git a/inbound-interaction-api.yaml b/inbound-interaction-api.yaml
index 75e2ef2..0e1379e 100644
--- a/inbound-interaction-api.yaml
+++ b/inbound-interaction-api.yaml
@@ -522,6 +522,61 @@ components:
       type: "string"
       description: "UUID that references a message"
       example: "57904eb6-5352-4c5e-adf6-5f100572cf5d"
+    AcknowledgementRequest:
+      type: object
+      description: "Request body for acknowledgement API"
+      properties:
+        sender:
+          $ref: '#/components/schemas/Participant'
+        conversationIdentifier:
+          type: string
+          description: Conversation Identifier
+          maxLength: 240
+        acknowledgements:
+          type: array
+          minItems: 1
+          maxItems: 25
+          description: "List of Read and Delivered acknowledgements"
+          items:
+            $ref: '#/components/schemas/Acknowledgement'
+      required:
+        - sender
+        - conversationIdentifier
+        - acknowledgements
+    Acknowledgement:
+      type: object
+      properties:
+        acknowledgementType:
+          $ref: '#/components/schemas/AcknowledgementType'
+        acknowledgedConversationEntryIdentifier:
+          type: string
+          description: The unique identifier for the conversation entry this acknowledgement is associated with
+        acknowledgmentCreatedConversationEntryIdentifier:
+          type: string
+          description: The client-supplied unique identifier to set when storing the new acknowledgement conversation entry
+        acknowledgementTimestamp:
+          type: string
+          description: The timestamp associated with the acknowledgement
+      required:
+        - acknowledgementType
+        - acknowledgedConversationEntryIdentifier
+        - acknowledgmentCreatedConversationEntryIdentifier
+        - acknowledgementTimestamp
+    AcknowledgementResponse:
+      type: object
+      description: "Response after sending read / delivered acknowledgment"
+      properties:
+        success:
+          type: boolean
+          description: Status of the consent status update request
+      required:
+        - success
+    AcknowledgementType:
+      description: Acknowledgement Type
+      type: string
+      enum:
+        - Read
+        - Delivered
 servers:
 - url: "/api/v1/"
 openapi: "3.0.0"
@@ -781,6 +836,56 @@ paths:
         in: "header"
         required: true
         example: "f7904eb6-5352-4c5e-adf6-5f100572cf5d"
+  /acknowledgement:
+    post:
+      summary: Marks messages as read / delivered
+      operationId: post-acknowledgement
+      responses:
+        default:
+          description: Unsuccessful operation
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/AcknowledgementResponse'
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/AcknowledgementResponse'
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/AcknowledgementRequest'
+      parameters:
+        - in: header
+          name: Authorization
+          description: "The access token generated to make requests to the Interaction Service APIs"
+          example: Bearer XXXXXX
+          required: true
+          schema:
+            type: string
+        - name: OrgId
+          in: header
+          description: "Organization Id used to verify the request against the auth token"
+          example: 00Dxxxxxxxxxxxx
+          required: true
+          schema:
+            type: string
+        - name: AuthorizationContext
+          in: header
+          description: "Specify the extra info for request authorization"
+          required: true
+          schema:
+            type: string
+        - name: RequestId
+          in: header
+          description: "UUID that references this request"
+          required: true
+          schema:
+            type: string
+          example: f7904eb6-5352-4c5e-adf6-5f100572cf5d
 info:
   title: "Interaction"
   version: "0.0.1"