---
title: "In-App Messaging – Delivery Logic & SDK Tracking (for Developers)"
slug: "in-app-messaging-delivery-logic-sdk-tracking-for-developers"
updated: 2025-07-23T09:24:26Z
published: 2025-07-23T09:24:26Z
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mapp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# In-App Messaging – Delivery Logic & SDK Tracking (for Developers)

This page explains the delivery flow of in-app messages in Mapp Engage from a technical perspective. It covers processing logic, SDK behavior, and event tracking codes.

---

## Overview

In-app messages in Mapp Engage follow distinct processing paths depending on the selected message type. Each message goes through multiple steps from event trigger to display or inbox storage. Developers can monitor these steps using SDK tracking events and delivery status codes.

---

## Message Processing Flow

The table below outlines the delivery steps for **In-App** and **Inbox** message types.

| **Step** | **In-App** | **Inbox** |
| --- | --- | --- |
| 1. Message Trigger | ✓ Triggered by app event | ✗ Not triggered |
| 2. Target Group Evaluation | ✓ Evaluated in real time | ✗ Not evaluated |
| 3. Server Processing | ✓ Prepared and queued | ✓ Added to message inbox |
| 4. SDK Delivery | ✓ Delivered to SDK in real time | ✗ No SDK delivery |
| 5. Display Constraints | ✓ Checked before display | ✗ Not evaluated |
| 6. Message Display | ✓ Shown immediately in app | ✗ Not shown directly |
| 7. Inbox Storage | ✗ Not stored | ✓ Stored in inbox |

> [!NOTE]
> Note
> 
> If a message is set to In-App + Inbox, both flows apply.

---

## Event Tracking & Status Codes

Mapp SDK logs delivery steps and errors using specific status codes. These codes help developers validate message delivery and troubleshoot issues.

| **Step** | **Event Code(s)** | **Applies to** |
| --- | --- | --- |
| 1. Message Trigger | `SKIPPED_NO_EVENT` | In-App |
| 2. Target Group Evaluation | `SKIPPED_NO_MATCHING_AUDIENCE` | In-App |
| 3. Server Processing | `CREATED_SUCCESSFULLY`, `CREATED_INBOX_ONLY` | Both |
| 4. SDK Delivery | `DELIVERED_TO_SDK`, `SDK_NOT_AVAILABLE` | In-App |
| 5. Display Constraints | `SKIPPED_CONSTRAINTS_NOT_MET`, `SKIPPED_TOO_FREQUENTLY` | In-App |
| 6. Message Display | `DISPLAYED` | In-App |
| 7. Inbox Storage | `STORED_IN_INBOX`, `NOT_ELIGIBLE_FOR_INBOX` | Inbox, In-App + Inbox |

---

## Technical Notes

- **Event Triggers:** Must be tracked via Mapp Mobile SDK. Untracked events will not initiate message delivery.
- **SDK Availability:** If the SDK is unavailable (e.g. during offline usage), real-time delivery will fail and is logged accordingly.
- **Constraint Checks:** Display frequency and visibility rules are enforced client-side before rendering.
- **Native vs. Web:** The rendering format (selected in Step 2 of message creation) determines how the SDK processes and displays the message:
  - *Web:* Delivered via WebView container.
  - *Native:* Renders using fixed templates directly within the app.