perf: drop jackson-module-kotlin, removing kotlin-reflect from the app

Nothing in the app binds JSON reflectively any more, so the module whose whole
job is reflective Kotlin binding has no work left to do. Swapping it for plain
jackson-databind takes kotlin-reflect out with it:

    kotlin.reflect.jvm.internal          969 -> 0 classes
    com.fasterxml.jackson.module.kotlin   73 -> 0 classes
    DEX                              30.94 MB -> 29.94 MB, 3 files -> 2

A megabyte and a whole secondary DEX, for code the app never called.

`jacksonObjectMapper()` became `ObjectMapper()` in all eight remaining places:
JacksonMapper and JsonMapperNip55 (both drive registered StdSerializer /
StdDeserializer pairs) and six readTree-only users (LNURL resolvers, TorService,
ArtiGuardState, Nip96Uploader). None of them needed the Kotlin module.

The one thing the module did that databind has no equivalent for is
`jacksonTypeRef<T>()`, which NIP-55 needs: `readValue<List<IntentResult>>` erases
to `List` under `T::class.java` and every element comes back a LinkedHashMap. It
is a one-liner — `reified` substitutes the concrete type into the anonymous
subclass before erasure — so it now lives in quartz as jacksonTypeRefOf().

quartz exported the module as an `api` dependency, so test sources three modules
away were quietly using it. Those move over too, same two swaps: `ObjectMapper()`
where the mapper only walks maps or readTree (the pretty-printer test, the BIP-39
vectors, the event-command benchmark, quic's qlog writer and its test), and
`jacksonTypeRefOf<ArrayList<Event>>()` where the reified `readValue<T>` extension
was doing the typeref's job (LargeDBSignatureCheck, the thread-order test, the
two cache benchmarks). Event's own deserializer is registered on the mapper, so
databind resolves it either way.

`cli` keeps the module. It genuinely binds its config files reflectively
(Config, OperatorKeys, Aliases, StatusReport), it declares the dependency itself,
and it is never minified, so none of this applies there. desktopApp, geode,
relayBench and quic-interop likewise declare it directly and are unaffected.

Verified: `./gradlew test` green, the instrumented sources compile
(:quartz:compileAndroidDeviceTestSources, :amethyst and :benchmark androidTest),
R8 release build green, 19/19 contract checks, and both package prefixes
confirmed at zero classes in the shipped DEX.

Note for whoever hits it next: a full recompile of :amethyst needs more than a
2 GB Kotlin daemon. Mine died with "Couldn't transform method node" pointing at a
Compose lambda in NoteCompose.kt, which is an OutOfMemoryError in the ASM frame
analyzer wearing a disguise, not a code fault.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DEoxktEZyTrAS33vVZBiwm

amethyst/src/androidTest/java/com/vitorpamplona/amethyst/ThreadDualAxisChartAssemblerTest.kt

@@ -21,7 +21,6 @@
 package com.vitorpamplona.amethyst
 
 import androidx.test.ext.junit.runners.AndroidJUnit4
-import com.fasterxml.jackson.module.kotlin.readValue
 import com.vitorpamplona.amethyst.commons.relayClient.assemblers.CashuMintDirectoryFilterAssembler
 import com.vitorpamplona.amethyst.commons.relayClient.nip47WalletConnect.NWCPaymentFilterAssembler
 import com.vitorpamplona.amethyst.commons.viewmodels.thread.ThreadFeedFilter
@@ -34,6 +33,7 @@ import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.crypto.KeyPair
 import com.vitorpamplona.quartz.nip01Core.crypto.verify
 import com.vitorpamplona.quartz.nip01Core.jackson.JacksonMapper
+import com.vitorpamplona.quartz.nip01Core.jackson.jacksonTypeRefOf
 import com.vitorpamplona.quartz.nip01Core.relay.client.NostrClient
 import com.vitorpamplona.quartz.nip01Core.signers.NostrSignerInternal
 import com.vitorpamplona.quartz.nip01Core.tags.aTag.ATag
@@ -163,7 +163,7 @@ class ThreadDualAxisChartAssemblerTest {
     fun threadOrderTest() =
         runBlocking {
             val eventArray =
-                JacksonMapper.mapper.readValue<List<Event>>(db) + Event.fromJson(header)
+                JacksonMapper.mapper.readValue(db, jacksonTypeRefOf<List<Event>>()) + Event.fromJson(header)
 
             var counter = 0
             eventArray.forEach {

amethyst/src/main/java/com/vitorpamplona/amethyst/service/lnurl/LightningAddressResolver.kt

@@ -21,7 +21,7 @@
 package com.vitorpamplona.amethyst.service.lnurl
 
 import android.content.Context
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.databind.ObjectMapper
 import com.vitorpamplona.amethyst.R
 import com.vitorpamplona.amethyst.service.HttpStatusMessages
 import com.vitorpamplona.amethyst.ui.stringRes
@@ -167,7 +167,7 @@ class LightningAddressResolver {
 
         val errorMessage =
             runCatching {
-                jacksonObjectMapper().readTree(body)
+                ObjectMapper().readTree(body)
             }.getOrNull()?.let { tree ->
                 val errorNode = tree.get("error")
                 val messageNode = tree.get("message")
@@ -218,7 +218,7 @@ class LightningAddressResolver {
         context: Context,
         onZapRequestSent: (LnZapRequestEvent?) -> Unit = {},
     ): String {
-        val mapper = jacksonObjectMapper()
+        val mapper = ObjectMapper()
 
         val lnurlpUrl = assembleUrl(lnAddress)
 

amethyst/src/main/java/com/vitorpamplona/amethyst/service/uploads/nip96/Nip96Uploader.kt

@@ -26,7 +26,7 @@ import android.net.Uri
 import android.provider.OpenableColumns
 import android.webkit.MimeTypeMap
 import androidx.core.net.toFile
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.databind.ObjectMapper
 import com.vitorpamplona.amethyst.R
 import com.vitorpamplona.amethyst.service.HttpStatusMessages
 import com.vitorpamplona.amethyst.service.checkNotInMainThread
@@ -209,7 +209,7 @@ class Nip96Uploader {
 
                     val errorMessage =
                         try {
-                            val tree = jacksonObjectMapper().readTree(msg)
+                            val tree = ObjectMapper().readTree(msg)
                             val status = tree.get("status")?.asText()
                             val message = tree.get("message")?.asText()
                             if (status == "error" && message != null) {

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/tor/ArtiGuardState.kt

@@ -21,7 +21,7 @@
 package com.vitorpamplona.amethyst.ui.tor
 
 import com.fasterxml.jackson.databind.JsonNode
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.databind.ObjectMapper
 
 /**
  * Pure, file- and JNI-free parsers over Arti's persisted guard sample
@@ -42,7 +42,7 @@ import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
  *   circuit — i.e. a real bootstrap reached the guard-confirmation stage.
  */
 object ArtiGuardState {
-    private val mapper = jacksonObjectMapper()
+    private val mapper = ObjectMapper()
 
     /** Convenience for tests/callers holding the raw file text. */
     fun parse(json: String): JsonNode = mapper.readTree(json)

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/tor/TorService.kt

@@ -22,7 +22,7 @@ package com.vitorpamplona.amethyst.ui.tor
 
 import android.content.Context
 import com.fasterxml.jackson.databind.JsonNode
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.databind.ObjectMapper
 import com.vitorpamplona.quartz.utils.Log
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -206,7 +206,7 @@ class TorService(
         val file = guardsFile()
         if (!file.exists()) return null
         return try {
-            jacksonObjectMapper().readTree(file)
+            ObjectMapper().readTree(file)
         } catch (e: Exception) {
             Log.w("TorService") { "Could not inspect guards.json: ${e.message}" }
             null

benchmark/src/androidTest/java/com/vitorpamplona/quartz/benchmark/BaseLargeCacheBenchmark.kt

@@ -20,10 +20,10 @@
  */
 package com.vitorpamplona.quartz.benchmark
 
-import com.fasterxml.jackson.module.kotlin.readValue
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.jackson.JacksonMapper
+import com.vitorpamplona.quartz.nip01Core.jackson.jacksonTypeRefOf
 import com.vitorpamplona.quartz.utils.cache.LargeCache
 import org.junit.Assert.assertTrue
 import java.util.function.Consumer
@@ -35,8 +35,9 @@ open class BaseLargeCacheBenchmark {
             // This file includes duplicates
             val fullDBInputStream = javaClass.classLoader!!.getResourceAsStream("nostr_vitor_startup_data.json.gz")
 
-            return JacksonMapper.mapper.readValue<ArrayList<Event>>(
+            return JacksonMapper.mapper.readValue(
                 GZIPInputStream(fullDBInputStream),
+                jacksonTypeRefOf<ArrayList<Event>>(),
             )
         }
     }

benchmark/src/androidTest/java/com/vitorpamplona/quartz/benchmark/CacheBenchmark.kt

@@ -23,10 +23,10 @@ package com.vitorpamplona.quartz.benchmark
 import androidx.benchmark.junit4.BenchmarkRule
 import androidx.benchmark.junit4.measureRepeated
 import androidx.test.ext.junit.runners.AndroidJUnit4
-import com.fasterxml.jackson.module.kotlin.readValue
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.jackson.JacksonMapper
+import com.vitorpamplona.quartz.nip01Core.jackson.jacksonTypeRefOf
 import com.vitorpamplona.quartz.utils.cache.LargeCache
 import org.junit.Assert.assertTrue
 import org.junit.Rule
@@ -43,8 +43,9 @@ open class BaseCacheBenchmark {
         // This file includes duplicates
         val fullDBInputStream = javaClass.classLoader?.getResourceAsStream("nostr_vitor_startup_data.json.gz")
 
-        return JacksonMapper.mapper.readValue<ArrayList<Event>>(
+        return JacksonMapper.mapper.readValue(
             GZIPInputStream(fullDBInputStream),
+            jacksonTypeRefOf<ArrayList<Event>>(),
         )
     }
 

benchmark/src/androidTest/java/com/vitorpamplona/quartz/benchmark/EventCmdSerializerBenchmark.kt

@@ -23,7 +23,7 @@ package com.vitorpamplona.quartz.benchmark
 import androidx.benchmark.junit4.BenchmarkRule
 import androidx.benchmark.junit4.measureRepeated
 import androidx.test.ext.junit.runners.AndroidJUnit4
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.databind.ObjectMapper
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.utils.sha256.Sha256Hasher
 import org.junit.Rule
@@ -54,7 +54,7 @@ class EventCmdSerializerBenchmark {
 
     @Test
     fun jsonStringEncoderJackson() {
-        val jsonMapper = jacksonObjectMapper()
+        val jsonMapper = ObjectMapper()
         benchmarkRule.measureRepeated {
             jsonMapper.writeValueAsString(specialEncoders)
         }
@@ -62,7 +62,7 @@ class EventCmdSerializerBenchmark {
 
     @Test
     fun jsonStringEncoderSha256Jackson() {
-        val jsonMapper = jacksonObjectMapper()
+        val jsonMapper = ObjectMapper()
         benchmarkRule.measureRepeated {
             val digest = Sha256Hasher()
             digest.hash(jsonMapper.writeValueAsString(specialEncoders).toByteArray())

commons/src/jvmAndroid/kotlin/com/vitorpamplona/amethyst/commons/service/lnurl/LightningAddressResolver.kt

@@ -20,7 +20,7 @@
  */
 package com.vitorpamplona.amethyst.commons.service.lnurl
 
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.databind.ObjectMapper
 import com.vitorpamplona.quartz.lightning.LnInvoiceUtil
 import com.vitorpamplona.quartz.lightning.Lud06
 import com.vitorpamplona.quartz.nip57Zaps.LnZapRequestEvent
@@ -48,7 +48,7 @@ import kotlin.coroutines.cancellation.CancellationException
 class LightningAddressResolver(
     private val httpClient: OkHttpClient,
 ) {
-    private val mapper = jacksonObjectMapper()
+    private val mapper = ObjectMapper()
 
     /**
      * Result of resolving a lightning address to a BOLT11 invoice.

commons/src/jvmAndroid/kotlin/com/vitorpamplona/amethyst/commons/service/lnurl/OkHttpLnurlEndpointResolver.kt

@@ -20,7 +20,7 @@
  */
 package com.vitorpamplona.amethyst.commons.service.lnurl
 
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.databind.ObjectMapper
 import com.vitorpamplona.quartz.nip57Zaps.validate.LnurlEndpointCache
 import com.vitorpamplona.quartz.nip57Zaps.validate.LnurlEndpointInfo
 import com.vitorpamplona.quartz.nip57Zaps.validate.LnurlEndpointResolver
@@ -47,7 +47,7 @@ import kotlin.coroutines.cancellation.CancellationException
 class OkHttpLnurlEndpointResolver(
     private val okHttpClient: (String) -> OkHttpClient,
 ) : LnurlEndpointResolver {
-    private val mapper = jacksonObjectMapper()
+    private val mapper = ObjectMapper()
 
     override suspend fun resolve(lnurlpUrl: String): LnurlEndpointInfo? = LnurlEndpointCache.getOrFetch(lnurlpUrl, ::fetch)
 

gradle/libs.versions.toml

@@ -38,6 +38,7 @@ firebaseBom = "34.19.0"
 fragmentKtx = "1.9.0"
 gms = "4.5.0"
 healthConnect = "1.1.0"
+jackson = "2.22.2"
 jacksonModuleKotlin = "2.22.2"
 javaKeyring = "1.0.4"
 kmpTorRuntime = "2.6.0"
@@ -203,6 +204,7 @@ google-mlkit-genai-rewriting = { group = "com.google.mlkit", name = "genai-rewri
 google-mlkit-genai-image-description = { group = "com.google.mlkit", name = "genai-image-description", version.ref = "genaiImageDescription" }
 google-mlkit-language-id = { group = "com.google.mlkit", name = "language-id", version.ref = "languageId" }
 google-mlkit-translate = { group = "com.google.mlkit", name = "translate", version.ref = "translate" }
+jackson-databind = { group = "com.fasterxml.jackson.core", name = "jackson-databind", version.ref = "jackson" }
 jackson-module-kotlin = { group = "com.fasterxml.jackson.module", name = "jackson-module-kotlin", version.ref = "jacksonModuleKotlin" }
 java-keyring = { group = "com.github.javakeyring", name = "java-keyring", version.ref = "javaKeyring" }
 kmp-tor-runtime = { group = "io.matthewnelson.kmp-tor", name = "runtime", version.ref = "kmpTorRuntime" }

quartz/build.gradle.kts

@@ -177,8 +177,16 @@ kotlin {
                 dependsOn(commonMain.get())
 
                 dependencies {
-                    // Performant Parser of JSONs into Events
+                    // Performant Parser of JSONs into Events.
-                    api(libs.jackson.module.kotlin)
+                    //
+                    // jackson-databind, NOT jackson-module-kotlin: the module exists to bind
+                    // Kotlin classes reflectively off their constructor parameter names, and
+                    // nothing in the app does that any more — every wire format goes through a
+                    // hand-written serializer or kotlinx. Dropping it takes kotlin-reflect with
+                    // it, which is ~1,000 classes of DEX the app never called. `cli` still
+                    // declares the module itself: it genuinely binds its config files
+                    // reflectively, and is never minified.
+                    api(libs.jackson.databind)
 
                     // Websockets API
                     implementation(libs.okhttp)

quartz/src/androidDeviceTest/kotlin/com/vitorpamplona/quartz/LargeDBSignatureCheck.kt

@@ -21,10 +21,10 @@
 package com.vitorpamplona.quartz
 
 import androidx.test.ext.junit.runners.AndroidJUnit4
-import com.fasterxml.jackson.module.kotlin.readValue
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.crypto.verify
 import com.vitorpamplona.quartz.nip01Core.jackson.JacksonMapper
+import com.vitorpamplona.quartz.nip01Core.jackson.jacksonTypeRefOf
 import junit.framework.TestCase.assertEquals
 import kotlinx.coroutines.runBlocking
 import org.junit.Assert.assertTrue
@@ -41,8 +41,9 @@ class LargeDBSignatureCheck {
             val fullDBInputStream = javaClass.classLoader?.getResourceAsStream("nostr_vitor_short.json")
 
             val eventArray =
-                JacksonMapper.mapper.readValue<ArrayList<Event>>(
+                JacksonMapper.mapper.readValue(
                     InputStreamReader(fullDBInputStream),
+                    jacksonTypeRefOf<ArrayList<Event>>(),
                 ) as List<Event>
 
             var counter = 0
@@ -61,8 +62,9 @@ class LargeDBSignatureCheck {
             val fullDBInputStream = javaClass.classLoader?.getResourceAsStream("nostr_vitor_startup_data.json.gz")
 
             val eventArray =
-                JacksonMapper.mapper.readValue<ArrayList<Event>>(
+                JacksonMapper.mapper.readValue(
                     GZIPInputStream(fullDBInputStream),
+                    jacksonTypeRefOf<ArrayList<Event>>(),
                 ) as List<Event>
 
             var counter = 0

quartz/src/androidDeviceTest/kotlin/com/vitorpamplona/quartz/nip06KeyDerivation/Bip39MnemonicsTest.kt

@@ -21,7 +21,7 @@
 package com.vitorpamplona.quartz.nip06KeyDerivation
 
 import androidx.test.ext.junit.runners.AndroidJUnit4
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.databind.ObjectMapper
 import com.vitorpamplona.quartz.nip01Core.core.toHexKey
 import com.vitorpamplona.quartz.utils.Hex
 import com.vitorpamplona.quartz.utils.RandomInstance
@@ -34,7 +34,7 @@ import org.junit.runner.RunWith
 @RunWith(AndroidJUnit4::class)
 class Bip39MnemonicsTest {
     private val tests =
-        jacksonObjectMapper()
+        ObjectMapper()
             .readTree(javaClass.classLoader?.getResourceAsStream("bip39.vectors.json"))
 
     @Test

quartz/src/androidMain/kotlin/com/vitorpamplona/quartz/nip55AndroidSigner/JsonMapperNip55.kt

@@ -26,9 +26,8 @@ import com.fasterxml.jackson.databind.ObjectMapper
 import com.fasterxml.jackson.databind.module.SimpleModule
 import com.fasterxml.jackson.databind.node.ArrayNode
 import com.fasterxml.jackson.databind.node.ObjectNode
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
-import com.fasterxml.jackson.module.kotlin.readValue
 import com.vitorpamplona.quartz.nip01Core.jackson.InliningTagArrayPrettyPrinter
+import com.vitorpamplona.quartz.nip01Core.jackson.jacksonTypeRefOf
 import com.vitorpamplona.quartz.nip55AndroidSigner.api.foreground.intents.results.IntentResult
 import com.vitorpamplona.quartz.nip55AndroidSigner.api.foreground.intents.results.IntentResultJsonDeserializer
 import com.vitorpamplona.quartz.nip55AndroidSigner.api.foreground.intents.results.IntentResultJsonSerializer
@@ -39,7 +38,7 @@ import java.io.InputStream
 
 object JsonMapperNip55 {
     val defaultMapper: ObjectMapper =
-        jacksonObjectMapper()
+        ObjectMapper()
             .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
             .enable(JsonReadFeature.ALLOW_UNESCAPED_CONTROL_CHARS.mappedFeature())
             .setDefaultPrettyPrinter(InliningTagArrayPrettyPrinter())
@@ -51,9 +50,9 @@ object JsonMapperNip55 {
                     .addSerializer(Permission::class.java, PermissionSerializer()),
             )
 
-    inline fun <reified T> fromJsonTo(json: String): T = defaultMapper.readValue<T>(json)
+    inline fun <reified T> fromJsonTo(json: String): T = defaultMapper.readValue(json, jacksonTypeRefOf<T>())
 
-    inline fun <reified T> fromJsonTo(json: InputStream): T = defaultMapper.readValue<T>(json)
+    inline fun <reified T> fromJsonTo(json: InputStream): T = defaultMapper.readValue(json, jacksonTypeRefOf<T>())
 
     fun toJson(event: ArrayNode): String = defaultMapper.writeValueAsString(event)
 

quartz/src/jvmAndroid/kotlin/com/vitorpamplona/quartz/nip01Core/jackson/JacksonMapper.kt

@@ -23,12 +23,10 @@ package com.vitorpamplona.quartz.nip01Core.jackson
 import com.fasterxml.jackson.core.json.JsonReadFeature
 import com.fasterxml.jackson.databind.DeserializationFeature
 import com.fasterxml.jackson.databind.JavaType
+import com.fasterxml.jackson.databind.ObjectMapper
 import com.fasterxml.jackson.databind.module.SimpleModule
 import com.fasterxml.jackson.databind.node.ArrayNode
 import com.fasterxml.jackson.databind.node.ObjectNode
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
-import com.fasterxml.jackson.module.kotlin.jacksonTypeRef
-import com.fasterxml.jackson.module.kotlin.readValue
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.core.OptimizedSerializable
 import com.vitorpamplona.quartz.nip01Core.core.RawJson
@@ -64,7 +62,7 @@ class JacksonMapper {
         val defaultPrettyPrinter = InliningTagArrayPrettyPrinter()
 
         val mapper =
-            jacksonObjectMapper()
+            ObjectMapper()
                 .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
                 .configure(DeserializationFeature.FAIL_ON_TRAILING_TOKENS, false)
                 .configure(DeserializationFeature.UNWRAP_ROOT_VALUE, false)
@@ -104,13 +102,13 @@ class JacksonMapper {
         /**
          * Shortcuts
          */
-        val eventTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRef<Event>())
+        val eventTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRefOf<Event>())
-        val tagArrayTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRef<TagArray>())
+        val tagArrayTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRefOf<TagArray>())
-        val rumorTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRef<Rumor>())
+        val rumorTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRefOf<Rumor>())
-        val eventTemplateTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRef<EventTemplate<Event>>())
+        val eventTemplateTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRefOf<EventTemplate<Event>>())
-        val eventListTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRef<List<Event>>())
+        val eventListTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRefOf<List<Event>>())
-        val messageTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRef<Message>())
+        val messageTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRefOf<Message>())
-        val commandTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRef<Command>())
+        val commandTypeInstance: JavaType = mapper.typeFactory.constructType(jacksonTypeRefOf<Command>())
 
         fun fromJson(json: String): Event = mapper.readValue(json, eventTypeInstance)
 
@@ -169,12 +167,12 @@ class JacksonMapper {
 
         inline fun <reified T : OptimizedSerializable> fromJsonTo(json: String): T {
             checkRegistered(T::class)
-            return mapper.readValue<T>(json)
+            return mapper.readValue(json, jacksonTypeRefOf<T>())
         }
 
         inline fun <reified T : OptimizedSerializable> fromJsonTo(json: InputStream): T {
             checkRegistered(T::class)
-            return mapper.readValue<T>(json)
+            return mapper.readValue(json, jacksonTypeRefOf<T>())
         }
 
         fun toJson(event: Event): String = EventManualSerializer.toJson(event.id, event.pubKey, event.createdAt, event.kind, event.tags, event.content, event.sig)

quartz/src/jvmAndroid/kotlin/com/vitorpamplona/quartz/nip01Core/jackson/JacksonTypeRef.kt

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.quartz.nip01Core.jackson
+
+import com.fasterxml.jackson.core.type.TypeReference
+
+/**
+ * A [TypeReference] carrying the full generic type, e.g. `List<Event>`.
+ *
+ * This is the one thing the app used jackson-module-kotlin for that plain
+ * jackson-databind has no equivalent of — and it is a one-liner, because `reified`
+ * substitutes the concrete type into the anonymous subclass before erasure can
+ * lose it. `T::class.java` cannot replace it: for `List<Event>` that erases to
+ * `List`, and every element comes back a LinkedHashMap.
+ *
+ * Copied here rather than kept as a dependency so the Kotlin module — and
+ * kotlin-reflect behind it, ~1,000 classes — can leave the app. The CLI still
+ * depends on the module directly, because it genuinely binds reflectively and is
+ * never minified.
+ */
+inline fun <reified T> jacksonTypeRefOf(): TypeReference<T> = object : TypeReference<T>() {}

quartz/src/jvmAndroidTest/kotlin/com/vitorpamplona/quartz/nip01Core/jackson/InliningTagArrayPrettyPrinterTest.kt

@@ -20,13 +20,13 @@
  */
 package com.vitorpamplona.quartz.nip01Core.jackson
 
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.databind.ObjectMapper
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
 class InliningTagArrayPrettyPrinterTest {
     val mapper =
-        jacksonObjectMapper().apply {
+        ObjectMapper().apply {
             setDefaultPrettyPrinter(InliningTagArrayPrettyPrinter())
         }
 

quic/src/jvmTest/kotlin/com/vitorpamplona/quic/interop/QlogWriter.kt

@@ -21,7 +21,6 @@
 package com.vitorpamplona.quic.interop
 
 import com.fasterxml.jackson.databind.ObjectMapper
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
 import com.vitorpamplona.quic.connection.EncryptionLevel
 import com.vitorpamplona.quic.observability.QlogObserver
 import java.io.BufferedWriter
@@ -295,7 +294,7 @@ class QlogWriter(
     }
 
     companion object {
-        private val DEFAULT_MAPPER: ObjectMapper = jacksonObjectMapper()
+        private val DEFAULT_MAPPER: ObjectMapper = ObjectMapper()
 
         private fun packetTypeFor(level: EncryptionLevel): String =
             when (level) {

quic/src/jvmTest/kotlin/com/vitorpamplona/quic/interop/QlogWriterTest.kt

@@ -20,7 +20,7 @@
  */
 package com.vitorpamplona.quic.interop
 
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.databind.ObjectMapper
 import com.vitorpamplona.quic.connection.EncryptionLevel
 import org.junit.Test
 import java.io.File
@@ -73,7 +73,7 @@ class QlogWriterTest {
         val lines = tmp.readLines().filter { it.isNotBlank() }
         assertTrue(lines.size >= 12, "expected >= 12 lines (header + at least 11 events) but got ${lines.size}")
 
-        val mapper = jacksonObjectMapper()
+        val mapper = ObjectMapper()
 
         // Line 1: qlog header.
         val header = mapper.readTree(lines[0])
@@ -128,7 +128,7 @@ class QlogWriterTest {
             w.onAlpnNegotiated("h3")
         }
         val lines = tmp.readLines().filter { it.isNotBlank() }
-        val mapper = jacksonObjectMapper()
+        val mapper = ObjectMapper()
         val event = mapper.readTree(lines[1])
         assertEquals(50L, event.get("time").asLong(), "time must be relative to constructor (1050 - 1000)")
     }
@@ -152,7 +152,7 @@ class QlogWriterTest {
             QlogWriter(tmp, odcidHex = "00").use { w ->
                 w.onPacketSent(EncryptionLevel.INITIAL, 0, 1200, emptyList())
             }
-            val mapper = jacksonObjectMapper()
+            val mapper = ObjectMapper()
             val lines = tmp.readLines().filter { it.isNotBlank() }
             val frames = mapper.readTree(lines[1]).get("data").get("frames")
             assertTrue(frames.isArray, "frames must be an array even when empty")