diff --git a/build.gradle.kts b/build.gradle.kts
index 44b600e7..afd6901d 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -1,6 +1,6 @@
 plugins {
-  kotlin("jvm") version Versions.kotlin
-  id("org.jmailen.kotlinter") version Versions.kotlinter
+  alias(libs.plugins.kotlin)
+  alias(libs.plugins.kotlinter)
 }
 
 // configurations shared with all the modules, except `buildSrc`
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
new file mode 100644
index 00000000..7174e139
--- /dev/null
+++ b/gradle/libs.versions.toml
@@ -0,0 +1,12 @@
+[versions]
+kotlin = "1.9.20"
+ktor = "2.3.4"
+[libraries]
+
+[bundles]
+
+[plugins]
+kotlin = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }
+kotlinter = { id = "org.jmailen.kotlinter", version = "3.10.0" } # FIXME 3.12.0
+test-logger = { id = "com.adarshr.test-logger", version = "3.2.0" }
+ktor = { id = "io.ktor.plugin", version.ref = "ktor" }
diff --git a/modules/app/build.gradle.kts b/modules/app/build.gradle.kts
index c73ed982..c686f8e8 100644
--- a/modules/app/build.gradle.kts
+++ b/modules/app/build.gradle.kts
@@ -1,8 +1,8 @@
 plugins {
   // https://kotlinlang.org/docs/kapt.html
-  kotlin("kapt")
-  kotlin("plugin.serialization") version Versions.kotlin
-  id("com.adarshr.test-logger") version Versions.testLogger
+  //kotlin("kapt")
+  kotlin("plugin.serialization") version "1.9.20"
+  alias(libs.plugins.test.logger)
 
   application
   // https://docs.gradle.org/current/userguide/idea_plugin.html
@@ -11,40 +11,40 @@ plugins {
 
 dependencies {
   implementation(platform("org.jetbrains.kotlin:kotlin-bom"))
-  implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:${Versions.kotlinxCoroutines}")
-  implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:${Versions.kotlinxSerialization}")
+  implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.7.3")
+  implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.6.0")
 
   // logging
-  implementation("org.slf4j:slf4j-api:${Versions.slf4j}")
-  runtimeOnly("ch.qos.logback:logback-classic:${Versions.logback}")
+  implementation("org.slf4j:slf4j-api:2.0.9")
+  runtimeOnly("ch.qos.logback:logback-classic:1.4.11")
 
   // config
-  implementation("com.sksamuel.hoplite:hoplite-core:${Versions.hoplite}")
-  implementation("com.sksamuel.hoplite:hoplite-yaml:${Versions.hoplite}")
+  implementation("com.sksamuel.hoplite:hoplite-core:2.7.5")
+  implementation("com.sksamuel.hoplite:hoplite-yaml:2.7.5")
 
   // cli
-  implementation("com.github.ajalt.clikt:clikt:${Versions.clikt}")
+  implementation("com.github.ajalt.clikt:clikt:4.2.0")
 
   // json
-  implementation("com.ubertob.kondor:kondor-core:${Versions.kondor}")
-  testImplementation("com.ubertob.kondor:kondor-tools:${Versions.kondor}")
+  implementation("com.ubertob.kondor:kondor-core:2.1.1")
+  testImplementation("com.ubertob.kondor:kondor-tools:2.1.1")
 
   // reactor
-  implementation("io.projectreactor:reactor-core:${Versions.reactor}")
-  implementation("io.projectreactor.kotlin:reactor-kotlin-extensions:${Versions.reactorKotlin}")
+  implementation("io.projectreactor:reactor-core:3.5.10")
+  implementation("io.projectreactor.kotlin:reactor-kotlin-extensions:1.2.2")
 
   // arrow
-  implementation(platform("io.arrow-kt:arrow-stack:${Versions.arrow}"))
+  implementation(platform("io.arrow-kt:arrow-stack:1.2.1"))
   implementation("io.arrow-kt:arrow-core")
   implementation("io.arrow-kt:arrow-fx-coroutines")
   implementation("io.arrow-kt:arrow-optics")
-  kapt("io.arrow-kt:arrow-meta:${Versions.arrowMeta}")
+  //kapt("io.arrow-kt:arrow-meta:1.6.2")
 
   // tests
-  testImplementation("io.kotest:kotest-runner-junit5:${Versions.kotest}")
-  testImplementation("io.kotest:kotest-assertions-core:${Versions.kotest}")
-  testImplementation("io.kotest:kotest-assertions-json:${Versions.kotest}")
-  testImplementation("io.kotest:kotest-property:${Versions.kotest}")
+  testImplementation("io.kotest:kotest-runner-junit5:5.7.2")
+  testImplementation("io.kotest:kotest-assertions-core:5.7.2")
+  testImplementation("io.kotest:kotest-assertions-json:5.7.2")
+  testImplementation("io.kotest:kotest-property:5.7.2")
   // TODO fix conflict
   //testImplementation("org.jetbrains.kotlin:kotlin-test")
   //testImplementation("org.jetbrains.kotlin:kotlin-test-junit")
diff --git a/modules/aws-kotlin/build.gradle.kts b/modules/aws-kotlin/build.gradle.kts
index 97ff92e8..4c51ff04 100644
--- a/modules/aws-kotlin/build.gradle.kts
+++ b/modules/aws-kotlin/build.gradle.kts
@@ -1,5 +1,5 @@
 dependencies {
-  implementation("aws.sdk.kotlin:lambda:${Versions.awsKotlin}")
-  implementation("org.slf4j:slf4j-api:${Versions.slf4j}")
-  runtimeOnly("ch.qos.logback:logback-classic:${Versions.logback}")
+  implementation("aws.sdk.kotlin:lambda:0.32.2-beta")
+  implementation("org.slf4j:slf4j-api:2.0.9")
+  runtimeOnly("ch.qos.logback:logback-classic:1.4.11")
 }
diff --git a/modules/aws-local/build.gradle.kts b/modules/aws-local/build.gradle.kts
index 4a93d00c..5faa5e49 100644
--- a/modules/aws-local/build.gradle.kts
+++ b/modules/aws-local/build.gradle.kts
@@ -1,6 +1,6 @@
 plugins {
-  id("com.adarshr.test-logger") version Versions.testLogger
-  id("com.github.johnrengelman.shadow") version Versions.shadow
+  alias(libs.plugins.test.logger)
+  id("com.github.johnrengelman.shadow") version "8.1.1"
   application
 }
 
@@ -9,19 +9,19 @@ dependencies {
   implementation(platform("org.jetbrains.kotlin:kotlin-bom"))
   implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
 
-  implementation("org.slf4j:slf4j-api:${Versions.slf4j}")
-  runtimeOnly("ch.qos.logback:logback-classic:${Versions.logback}")
+  implementation("org.slf4j:slf4j-api:2.0.9")
+  runtimeOnly("ch.qos.logback:logback-classic:1.4.11")
 
   // aws
-  implementation(platform("software.amazon.awssdk:bom:${Versions.aws}"))
+  implementation(platform("software.amazon.awssdk:bom:2.20.153"))
   implementation("software.amazon.awssdk:lambda")
   implementation("software.amazon.awssdk:s3")
   implementation("software.amazon.awssdk:sqs")
-  implementation("com.amazonaws:aws-lambda-java-core:${Versions.awsLambdaCore}")
-  implementation("com.amazonaws:aws-lambda-java-events:${Versions.awsLambdaEvents}")
+  implementation("com.amazonaws:aws-lambda-java-core:1.2.3")
+  implementation("com.amazonaws:aws-lambda-java-events:3.11.3")
 
   // tests
-  testImplementation("io.kotest:kotest-runner-junit5:${Versions.kotest}")
+  testImplementation("io.kotest:kotest-runner-junit5:5.7.2")
 }
 
 application {
diff --git a/modules/aws-serverless/build.gradle.kts b/modules/aws-serverless/build.gradle.kts
index 113a09e1..d9858495 100644
--- a/modules/aws-serverless/build.gradle.kts
+++ b/modules/aws-serverless/build.gradle.kts
@@ -1,12 +1,12 @@
 plugins {
-  id("com.adarshr.test-logger") version Versions.testLogger
+  alias(libs.plugins.test.logger)
 }
 
 version = "0.1.0"
 
 dependencies {
-  implementation("com.amazonaws:aws-lambda-java-core:${Versions.awsLambdaCore}")
-  implementation("com.amazonaws:aws-lambda-java-events:${Versions.awsLambdaEvents}")
+  implementation("com.amazonaws:aws-lambda-java-core:1.2.3")
+  implementation("com.amazonaws:aws-lambda-java-events:3.11.3")
 
   // https://docs.aws.amazon.com/lambda/latest/dg/java-logging.html#java-logging-log4j2
   implementation("org.apache.logging.log4j:log4j-api:2.19.0")
diff --git a/modules/bool/build.gradle.kts b/modules/bool/build.gradle.kts
index 2020388f..b6594743 100644
--- a/modules/bool/build.gradle.kts
+++ b/modules/bool/build.gradle.kts
@@ -1,10 +1,10 @@
 plugins {
-  id("com.adarshr.test-logger") version Versions.testLogger
+  alias(libs.plugins.test.logger)
 }
 
 dependencies {
-  testImplementation("io.kotest:kotest-runner-junit5:${Versions.kotest}")
-  testImplementation("io.kotest:kotest-assertions-core:${Versions.kotest}")
+  testImplementation("io.kotest:kotest-runner-junit5:5.7.2")
+  testImplementation("io.kotest:kotest-assertions-core:5.7.2")
 }
 
 tasks.withType<Test> {
diff --git a/modules/http/build.gradle.kts b/modules/http/build.gradle.kts
index f9c0cdd0..364b0d81 100644
--- a/modules/http/build.gradle.kts
+++ b/modules/http/build.gradle.kts
@@ -1,23 +1,22 @@
 plugins {
-  id("com.adarshr.test-logger") version Versions.testLogger
+  alias(libs.plugins.test.logger)
 
   application
-  // TODO is this used?
-  id("io.ktor.plugin") version Versions.ktor
+  alias(libs.plugins.ktor)
 }
 
 dependencies {
   // server
-  implementation("io.ktor:ktor-server-core-jvm:${Versions.ktor}")
-  implementation("io.ktor:ktor-server-netty-jvm:${Versions.ktor}")
+  implementation("io.ktor:ktor-server-core-jvm:2.3.4")
+  implementation("io.ktor:ktor-server-netty-jvm:2.3.4")
 
   // logging
-  implementation("org.slf4j:slf4j-api:${Versions.slf4j}")
-  runtimeOnly("ch.qos.logback:logback-classic:${Versions.logback}")
+  implementation("org.slf4j:slf4j-api:2.0.9")
+  runtimeOnly("ch.qos.logback:logback-classic:1.4.11")
 
   // testing
-  testImplementation("io.ktor:ktor-server-tests-jvm:${Versions.ktor}")
-  testImplementation("org.jetbrains.kotlin:kotlin-test-junit:${Versions.kotlin}")
+  testImplementation("io.ktor:ktor-server-tests-jvm:2.3.4")
+  testImplementation("org.jetbrains.kotlin:kotlin-test-junit:1.9.20")
 }
 
 application {
diff --git a/modules/jok/build.gradle.kts b/modules/jok/build.gradle.kts
index a6e07fc0..311fd099 100644
--- a/modules/jok/build.gradle.kts
+++ b/modules/jok/build.gradle.kts
@@ -1,7 +1,7 @@
 dependencies {
   implementation(kotlin("script-runtime"))
 
-  implementation("org.jdom:jdom2:${Versions.jdom}")
+  implementation("org.jdom:jdom2:2.0.6.1")
 }
 
 // ------------------------------
diff --git a/modules/json-schema/build.gradle.kts b/modules/json-schema/build.gradle.kts
index f8385c26..e02fa291 100644
--- a/modules/json-schema/build.gradle.kts
+++ b/modules/json-schema/build.gradle.kts
@@ -1,5 +1,5 @@
 plugins {
-  id("com.adarshr.test-logger") version Versions.testLogger
+  alias(libs.plugins.test.logger)
 }
 
 repositories {
@@ -8,21 +8,21 @@ repositories {
 
 dependencies {
   // json schema
-  implementation("com.github.erosb:everit-json-schema:${Versions.everit}")
-  implementation("net.pwall.json:json-kotlin-schema:${Versions.pwall}")
+  implementation("com.github.erosb:everit-json-schema:1.14.2")
+  implementation("net.pwall.json:json-kotlin-schema:0.42")
 
   // json-schema compatibility
-  implementation("io.confluent:kafka-json-schema-provider:${Versions.confluent}")
-  testImplementation("io.confluent:kafka-schema-registry:${Versions.confluent}")
-  testImplementation("io.kotest.extensions:kotest-extensions-embedded-kafka:${Versions.kotestKafka}")
+  implementation("io.confluent:kafka-json-schema-provider:7.3.3") // FIXME 7.4.0
+  testImplementation("io.confluent:kafka-schema-registry:7.3.3")
+  testImplementation("io.kotest.extensions:kotest-extensions-embedded-kafka:2.0.0") // deprecated, see testcontainers
 
   // json diff
-  implementation("com.flipkart.zjsonpatch:zjsonpatch:${Versions.zjsonpatch}")
-  implementation("com.fasterxml.jackson.module:jackson-module-kotlin:${Versions.jackson}")
+  implementation("com.flipkart.zjsonpatch:zjsonpatch:0.4.14")
+  implementation("com.fasterxml.jackson.module:jackson-module-kotlin:2.15.2")
 
   // testing
-  testImplementation("io.kotest:kotest-runner-junit5:${Versions.kotest}")
-  testImplementation("io.kotest:kotest-assertions-core:${Versions.kotest}")
+  testImplementation("io.kotest:kotest-runner-junit5:5.7.2")
+  testImplementation("io.kotest:kotest-assertions-core:5.7.2")
 }
 
 tasks.withType<Test> {
diff --git a/modules/lox/build.gradle.kts b/modules/lox/build.gradle.kts
index 02499efd..301ee272 100644
--- a/modules/lox/build.gradle.kts
+++ b/modules/lox/build.gradle.kts
@@ -1,10 +1,10 @@
 plugins {
-  id("com.adarshr.test-logger") version Versions.testLogger
+  alias(libs.plugins.test.logger)
 }
 
 dependencies {
-  testImplementation("io.kotest:kotest-runner-junit5:${Versions.kotest}")
-  testImplementation("io.kotest:kotest-assertions-core:${Versions.kotest}")
+  testImplementation("io.kotest:kotest-runner-junit5:5.7.2")
+  testImplementation("io.kotest:kotest-assertions-core:5.7.2")
 }
 
 tasks.withType<Test> {
diff --git a/modules/rekursive/build.gradle.kts b/modules/rekursive/build.gradle.kts
index 2d6f8541..3e1a0640 100644
--- a/modules/rekursive/build.gradle.kts
+++ b/modules/rekursive/build.gradle.kts
@@ -1,10 +1,10 @@
 plugins {
-  id("com.adarshr.test-logger") version Versions.testLogger
+  alias(libs.plugins.test.logger)
 }
 
 dependencies {
-  testImplementation("io.kotest:kotest-runner-junit5:${Versions.kotest}")
-  testImplementation("io.kotest:kotest-assertions-core:${Versions.kotest}")
+  testImplementation("io.kotest:kotest-runner-junit5:5.7.2")
+  testImplementation("io.kotest:kotest-assertions-core:5.7.2")
 }
 
 tasks.withType<Test> {