[AI] Enable Ktor logging for debug builds in firebase-ai

ai-logic/firebase-ai/firebase-ai.gradle.kts

@@ -51,6 +51,7 @@ android {
       proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
     }
   }
+  buildFeatures { buildConfig = true }
   compileOptions {
     sourceCompatibility = JavaVersion.VERSION_1_8
     targetCompatibility = JavaVersion.VERSION_1_8
@@ -89,7 +90,6 @@ dependencies {
   implementation(libs.androidx.annotation)
   implementation(libs.kotlinx.serialization.json)
   implementation(libs.androidx.core.ktx)
-  implementation(libs.slf4j.nop)
   implementation(libs.kotlinx.coroutines.android)
   implementation(libs.kotlinx.coroutines.reactive)
   implementation(libs.reactive.streams)
@@ -99,6 +99,10 @@ dependencies {
   implementation("com.google.firebase:firebase-auth-interop:18.0.0")
   implementation("com.google.firebase:firebase-ai-ondevice-interop:16.0.0-beta01")
 
+  // Use different logging libraries depending on the variant
+  releaseImplementation(libs.slf4j.nop)
+  debugImplementation(libs.slf4j.simple)
+
   testImplementation(libs.kotest.assertions.core)
   testImplementation(libs.kotest.assertions)
   testImplementation(libs.kotest.assertions.json)

ai-logic/firebase-ai/src/main/kotlin/com/google/firebase/ai/common/APIController.kt

@@ -22,6 +22,7 @@ import android.os.Build
 import android.util.Log
 import com.google.firebase.Firebase
 import com.google.firebase.FirebaseApp
+import com.google.firebase.ai.BuildConfig
 import com.google.firebase.ai.common.util.decodeToFlow
 import com.google.firebase.ai.common.util.fullModelName
 import com.google.firebase.ai.type.APINotConfiguredException
@@ -51,6 +52,8 @@ import io.ktor.client.engine.HttpClientEngine
 import io.ktor.client.engine.okhttp.OkHttp
 import io.ktor.client.plugins.HttpTimeout
 import io.ktor.client.plugins.contentnegotiation.ContentNegotiation
+import io.ktor.client.plugins.logging.LogLevel
+import io.ktor.client.plugins.logging.Logging
 import io.ktor.client.plugins.websocket.DefaultClientWebSocketSession
 import io.ktor.client.plugins.websocket.WebSockets
 import io.ktor.client.plugins.websocket.webSocketSession
@@ -155,6 +158,15 @@ internal constructor(
       }
       install(WebSockets)
       install(ContentNegotiation) { json(JSON) }
+      if (BuildConfig.DEBUG) {
+        install(Logging) {
+          sanitizeHeader { header ->
+            header.equals("X-Android-Cert", ignoreCase = true) ||
+              header.equals("x-goog-api-key", ignoreCase = true)
+          }
+          level = LogLevel.ALL
+        }
+      }
     }
 
   suspend fun generateContent(request: GenerateContentRequest): GenerateContentResponse.Internal =

gradle/libs.versions.toml

@@ -69,7 +69,7 @@ runner = "1.0.2"
 rxandroid = "2.0.2"
 rxjava = "2.2.21"
 serialization = "1.7.3"
-slf4jNop = "2.0.17"
+slf4j = "2.0.17"
 spotless = "7.0.4"
 symbolProcessingApi = "2.2.10-2.0.2"
 testServices = "1.6.0"
@@ -207,7 +207,8 @@ robolectric = { module = "org.robolectric:robolectric", version.ref = "robolectr
 runner = { module = "com.android.support.test:runner", version.ref = "runner" }
 rxandroid = { module = "io.reactivex.rxjava2:rxandroid", version.ref = "rxandroid" }
 rxjava = { module = "io.reactivex.rxjava2:rxjava", version.ref = "rxjava" }
-slf4j-nop = { module = "org.slf4j:slf4j-nop", version.ref = "slf4jNop" }
+slf4j-nop = { module = "org.slf4j:slf4j-nop", version.ref = "slf4j" }
+slf4j-simple = { module = "org.slf4j:slf4j-simple", version.ref = "slf4j" }
 spotless-plugin-gradle = { module = "com.diffplug.spotless:spotless-plugin-gradle", version.ref = "spotless" }
 symbol-processing-api = { module = "com.google.devtools.ksp:symbol-processing-api", version.ref = "symbolProcessingApi" }
 truth = { module = "com.google.truth:truth", version.ref = "truth" }