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](https://github.com/mobile-next/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`: ```kotlin // 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: ```json { "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: ```sh ./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 ```sh # 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 ```sh 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`): ```json [ { "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 |