diff --git a/zipline-gradle-plugin/build.gradle.kts b/zipline-gradle-plugin/build.gradle.kts
index 1f7b4e4f04..164f64475a 100644
--- a/zipline-gradle-plugin/build.gradle.kts
+++ b/zipline-gradle-plugin/build.gradle.kts
@@ -22,6 +22,7 @@ dependencies {
   implementation(kotlin("gradle-plugin-api"))
   implementation(projects.zipline)
   implementation(projects.ziplineBytecode)
+  implementation(projects.ziplineKotlinPlugin)
   implementation(projects.ziplineLoader)
   implementation(libs.http4k.core)
   implementation(libs.http4k.server.jetty)
diff --git a/zipline-gradle-plugin/src/main/kotlin/app/cash/zipline/gradle/ZiplineApiDumpTask.kt b/zipline-gradle-plugin/src/main/kotlin/app/cash/zipline/gradle/ZiplineApiDumpTask.kt
new file mode 100644
index 0000000000..8920eb48cf
--- /dev/null
+++ b/zipline-gradle-plugin/src/main/kotlin/app/cash/zipline/gradle/ZiplineApiDumpTask.kt
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2023 Cash App
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package app.cash.zipline.gradle
+
+import app.cash.zipline.api.compatibility.ActualApiHasProblems
+import app.cash.zipline.api.compatibility.ExpectedApiIsUpToDate
+import app.cash.zipline.api.compatibility.ExpectedApiRequiresUpdates
+import app.cash.zipline.api.compatibility.makeApiCompatibilityDecision
+import app.cash.zipline.api.fir.readFirZiplineApi
+import app.cash.zipline.api.toml.TomlZiplineApi
+import app.cash.zipline.api.toml.readZiplineApi
+import app.cash.zipline.api.toml.writeZiplineApi
+import javax.inject.Inject
+import okio.buffer
+import okio.sink
+import okio.source
+import org.gradle.api.DefaultTask
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.internal.file.FileCollectionFactory
+import org.gradle.api.tasks.Classpath
+import org.gradle.api.tasks.InputFiles
+import org.gradle.api.tasks.OutputFile
+import org.gradle.api.tasks.TaskAction
+
+@Suppress("unused") // Public API for Gradle plugin users.
+abstract class ZiplineApiDumpTask @Inject constructor(
+  fileCollectionFactory: FileCollectionFactory,
+) : DefaultTask() {
+
+  @get:OutputFile
+  abstract val ziplineApiFile: RegularFileProperty
+
+  @get:InputFiles
+  internal val sourcepath = fileCollectionFactory.configurableFiles("sourcepath")
+
+  @get:Classpath
+  internal val classpath = fileCollectionFactory.configurableFiles("classpath")
+
+  @TaskAction
+  fun task() {
+    val tomlFile = ziplineApiFile.get().asFile
+
+    val expectedZiplineApi = when {
+      tomlFile.exists() -> tomlFile.source().buffer().use { it.readZiplineApi() }
+      else -> TomlZiplineApi(listOf())
+    }
+
+    val actualZiplineApi = readFirZiplineApi(sourcepath.files, classpath.files)
+
+    when (val decision = makeApiCompatibilityDecision(expectedZiplineApi, actualZiplineApi)) {
+      is ActualApiHasProblems -> {
+        throw Exception(
+          """
+          |Zipline API has compatibility problems:
+          |  ${decision.messages.joinToString(separator = "\n").replace("\n", "\n  ") }
+          """.trimMargin(),
+        )
+      }
+
+      is ExpectedApiRequiresUpdates -> {
+        tomlFile.sink().buffer().use { it.writeZiplineApi(decision.updatedApi) }
+      }
+
+      ExpectedApiIsUpToDate -> {
+        // Do nothing.
+      }
+    }
+  }
+}
diff --git a/zipline-gradle-plugin/src/main/kotlin/app/cash/zipline/gradle/ZiplinePlugin.kt b/zipline-gradle-plugin/src/main/kotlin/app/cash/zipline/gradle/ZiplinePlugin.kt
index 9e403ea794..2e597cc80e 100644
--- a/zipline-gradle-plugin/src/main/kotlin/app/cash/zipline/gradle/ZiplinePlugin.kt
+++ b/zipline-gradle-plugin/src/main/kotlin/app/cash/zipline/gradle/ZiplinePlugin.kt
@@ -27,6 +27,8 @@ import org.jetbrains.kotlin.gradle.plugin.SubpluginOption
 import org.jetbrains.kotlin.gradle.targets.js.ir.JsIrBinary
 import org.jetbrains.kotlin.gradle.targets.js.ir.KotlinJsIrTarget
 import org.jetbrains.kotlin.gradle.targets.js.webpack.KotlinWebpack
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompileTool
 import org.slf4j.LoggerFactory
 
 @Suppress("unused") // Created reflectively by Gradle.
@@ -74,6 +76,12 @@ class ZiplinePlugin : KotlinCompilerPluginSupportPlugin {
         it.dependsOn(kotlinWebpack)
       }
     }
+
+    target.tasks.withType(KotlinCompile::class.java) { kotlinCompile ->
+      if (kotlinCompile.name == "compileKotlinJvm") {
+        registerZiplineApiDumpTask(target, kotlinCompile)
+      }
+    }
   }
 
   private fun registerCompileZiplineTask(
@@ -105,6 +113,24 @@ class ZiplinePlugin : KotlinCompilerPluginSupportPlugin {
     return ziplineCompileTask
   }
 
+  private fun registerZiplineApiDumpTask(
+    project: Project,
+    kotlinCompileTool: KotlinCompileTool,
+  ): TaskProvider<ZiplineApiDumpTask> {
+    val result = project.tasks.register(
+      "ziplineApiDump",
+      ZiplineApiDumpTask::class.java,
+    )
+
+    result.configure {
+      it.ziplineApiFile.set(project.file("api/zipline-api.toml"))
+      it.sourcepath.setFrom(kotlinCompileTool.sources)
+      it.classpath.setFrom(kotlinCompileTool.libraries)
+    }
+
+    return result
+  }
+
   override fun applyToCompilation(
     kotlinCompilation: KotlinCompilation<*>,
   ): Provider<List<SubpluginOption>> {
diff --git a/zipline-gradle-plugin/src/test/kotlin/app/cash/zipline/gradle/ZiplinePluginTest.kt b/zipline-gradle-plugin/src/test/kotlin/app/cash/zipline/gradle/ZiplinePluginTest.kt
index 7fd84281c4..5dec2261c4 100644
--- a/zipline-gradle-plugin/src/test/kotlin/app/cash/zipline/gradle/ZiplinePluginTest.kt
+++ b/zipline-gradle-plugin/src/test/kotlin/app/cash/zipline/gradle/ZiplinePluginTest.kt
@@ -195,6 +195,36 @@ class ZiplinePluginTest {
     )
   }
 
+  @Test
+  fun ziplineApiDumpCreatesTomlFile() {
+    val projectDir = File("src/test/projects/basic")
+    val ziplineApiToml = projectDir.resolve("lib/api/zipline-api.toml")
+
+    try {
+      val taskName = ":lib:ziplineApiDump"
+      val result = createRunner(projectDir, "clean", taskName).build()
+      assertThat(SUCCESS_OUTCOMES)
+        .contains(result.task(taskName)!!.outcome)
+
+      assertThat(ziplineApiToml.readText()).isEqualTo(
+        """
+        |[app.cash.zipline.tests.GreetService]
+        |
+        |functions = [
+        |  # fun close(): kotlin.Unit
+        |  "moYx+T3e",
+        |
+        |  # fun greet(kotlin.String): kotlin.String
+        |  "ipvircui",
+        |]
+        |
+        """.trimMargin(),
+      )
+    } finally {
+      ziplineApiToml.delete()
+    }
+  }
+
   private fun createRunner(projectDir: File, vararg taskNames: String): GradleRunner {
     val gradleRoot = projectDir.resolve("gradle").also { it.mkdir() }
     File("../gradle/wrapper").copyRecursively(gradleRoot.resolve("wrapper"), true)