Android SDK Event Inspection

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 |