android-sdk-event-inspection

name	android-sdk-event-inspection
description	Use when verifying SDK event payloads in the Android SDK sandbox, debugging what events are emitted, or validating request bodies via logcat with the sample Kotlin app.

Datadog Android SDK — Event Inspection

Overview

The Android SDK uses CurlInterceptor to log every outgoing HTTP request as a curl command. In debug builds, enabling printBody = true exposes the full JSON payloads sent to intake endpoints.

Core principle: Enable body logging BEFORE building, then rebuild + reinstall. Build-time config (config/{flavor}.json) is baked into BuildConfig — changes only take effect after a fresh build.

When to Use

• Verifying a change emits the correct event type or fields
• Checking custom attributes appear on a log, trace, RUM, Session Replay or Profiling event
• Debugging why RUM/logs/traces/Session Replay/Profiling are not showing up in Datadog
• Validating SDK behavior with the sample/kotlin app

Related Tools

mobile-mcp — use alongside this skill to interact with the device and generate events (taps, navigation, actions) that you then observe via logcat.

Setup

1. Enable Request Body Logging

In dd-sdk-android-core/src/main/kotlin/com/datadog/android/core/internal/CoreFeature.kt, find the OkHttpClient builder block inside if (BuildConfig.DEBUG) and enable body printing on the CurlInterceptor:

// Before (body suppressed):
builder.addNetworkInterceptor(CurlInterceptor())

// After (full JSON payloads visible):
builder.addNetworkInterceptor(CurlInterceptor(printBody = true))

This change is gated by BuildConfig.DEBUG — it only runs in debug builds.

2. Configure Build-Time Credentials

Create config/{flavor}.json (e.g., config/us1.json) — values are injected into BuildConfig at compile time. Fake/placeholder values are fine — real Datadog credentials are not required for local event inspection:

{
  "token": "pub<32-hex-chars>",
  "rumApplicationId": "<uuid>",
  "apiKey": "<40-hex-chars>",
  "applicationKey": "<40-hex-chars>",
  "logsEndpoint": "https://browser-intake-datadoghq.com",
  "tracesEndpoint": "https://browser-intake-datadoghq.com",
  "rumEndpoint": "https://browser-intake-datadoghq.com",
  "sessionReplayEndpoint": "https://browser-intake-datadoghq.com"
}

Token format must be pub + 32 hex chars. Any UUID works for rumApplicationId. The SDK will emit and batch events locally even with fake credentials (401 errors on intake are expected and harmless).

3. Build and Install

Ensure JAVA_HOME and ANDROID_HOME are set in your environment, then run:

./gradlew :sample:kotlin:install{Flavor}Debug
# e.g. installUs1Debug, installStagingDebug

Full environment setup (Java, Android SDK, emulator) belongs in AGENTS.md (not yet created — tracked as follow-up work).

4. Launch the App

# Find the launcher activity (run once to confirm):
adb shell dumpsys package com.datadog.android.sample | grep -A2 "MAIN"
# → com.datadog.android.sample/.NavActivity

adb shell am start -n com.datadog.android.sample/.NavActivity

5. Stream Logcat

adb logcat -s "Datadog" "DD_LOG" "Curl" "*:S"

Log Tags Quick Reference

Tag	What it shows
Datadog	User-facing SDK warnings and info (init, feature flags)
DD_LOG	Internal debug: queue state, upload decisions, errors
Curl	Full outgoing HTTP requests including JSON body

Event Structure in Curl Logs

Each Curl log line is a single curl command. The -d argument contains the request body:

Logs (/api/v2/logs):

[
  {
    "message": "onStart",
    "status": "debug",
    "service": "com.datadog.android.sample",
    "date": "...",
    "application_id": "...",
    "session_id": "...",
    "view.id": "...",
    "usr": { "id": "...", "anonymous_id": "..." },
    "ddtags": "build_type:debug,flavor:us1,env:debug,..."
  }
]

Session Replay (/api/v2/replay): multipart/form-data — image parts (WebP) are only present when recording in image mode; wireframe mode produces a different body structure.

RUM (/api/v2/rum): newline-delimited JSON events.

Traces (/api/v2/traces): application/msgpack — binary, not readable as text.

Profiling (/api/v2/profile): multipart/form-data with a perfetto.proto attachment.

Key Fields

What to check	Field path
Event source	URL path in the curl command
Log message	message
RUM app ID	application_id
Session	session_id
View	view.id
User	usr.id, usr.anonymous_id
Tags	ddtags
Build variant	ddtags contains flavor:us1,build_type:debug

Common Mistakes

Mistake	Fix
No Curl logs appear	CurlInterceptor only runs when BuildConfig.DEBUG = true; confirm you're on a debug build
Curl logs show but body is ''	printBody = false (default) — change to CurlInterceptor(printBody = true) and rebuild
rumApplicationId is empty in payload	config/us1.json was created after last build — rebuild + reinstall
Activity class does not exist error	Wrong activity name; run dumpsys package to find the correct one
Logcat shows no events after launch	Wait ~15 seconds for the first upload cycle; SDK batches before sending
401 errors on feature flags	Expected with fake credentials — logs/RUM/traces still emit and batch locally