diff --git a/build.gradle.kts b/build.gradle.kts
new file mode 100644
index 00000000..17d61b48
--- /dev/null
+++ b/build.gradle.kts
@@ -0,0 +1,30 @@
+plugins {
+   id("software.amazon.smithy").version("0.6.0")
+}
+
+buildscript {
+    dependencies {
+
+        // This dependency is required in order to apply the "openapi"
+        // plugin in smithy-build.json
+        classpath("software.amazon.smithy:smithy-openapi:1.29.0")
+    }
+}
+
+repositories {
+    mavenLocal()
+    mavenCentral()
+}
+
+dependencies {
+    implementation("software.amazon.smithy:smithy-model:1.29.0")
+    implementation("software.amazon.smithy:smithy-aws-traits:1.29.0")
+}
+
+configure<software.amazon.smithy.gradle.SmithyExtension> {
+    // Uncomment this to use a custom projection when building the JAR.
+    // projection = "foo"
+}
+
+// Uncomment to disable creating a JAR.
+//tasks["jar"].enabled = false
diff --git a/idl/k2v.smithy b/idl/k2v.smithy
deleted file mode 100644
index 62eb106b..00000000
--- a/idl/k2v.smithy
+++ /dev/null
@@ -1,53 +0,0 @@
-$version: "2"
-namespace org.deuxfleurs.garage.k2v
-
-service Item {
-    version: "2023-04-10"
-    resources: [ Item ]
-    operations: [ PollItem ]
-}
-
-resource Item {
-  read: ReadItem
-  put: InsertItem
-  delete: DeleteItem
-  list: ReadIndex
-}
-
-operation ReadItem {
-  input: ReadItemInput
-  output: ReadItemOutput
-}
-
-@input
-structure ReadItemInput {
-  bucket: String
-  partitionKey: String
-  sortKey: String
-}
-
-@output
-union ReadItemOutput {
-  list: ReadItemOutputList
-  raw: blob
-}
-
-@sparse
-list ReadItemOutputList {
-  member: String
-}
-
-operation PollItem {
-  input:
-  output:
-}
-
-operation InsertItem {
-  input:
-  output:
-}
-
-operation DeleteItem {
-  input:
-  output:
-}
diff --git a/model/k2v.smithy b/model/k2v.smithy
new file mode 100644
index 00000000..bf51f25b
--- /dev/null
+++ b/model/k2v.smithy
@@ -0,0 +1,96 @@
+$version: "2"
+namespace org.deuxfleurs.garage.k2v
+
+use aws.api#service
+use aws.auth#sigv4
+use aws.protocols#restJson1
+
+@service(sdkId: "k2v")
+@sigv4(name: "k2v")
+@restJson1
+service K2V {
+    version: "2023-04-10"
+    resources: [ Item ]
+    //operations: [ PollItem, ReadIndex, InsertBatch, DeleteBatch, PollRange ]
+}
+
+resource Item {
+  read: ReadItem
+  put: InsertItem
+  //delete: DeleteItem
+  //list: ReadBatch
+}
+
+@mixin
+structure KeySelector {
+  @required
+  @httpLabel
+  bucketName: String
+
+  @required
+  @httpLabel
+  partitionKey: String
+
+  @required
+  @httpQuery("sort_key")
+  sortKey: String
+}
+
+@readonly
+@http(method: "GET", uri: "/{bucketName}/{partitionKey}", code: 200)
+operation ReadItem {
+  input: ReadItemInput
+  output: ReadItemOutput
+}
+
+@input
+structure ReadItemInput with [KeySelector] {}
+
+@output
+structure ReadItemOutput {
+  value: ItemList
+}
+
+@sparse
+list ItemList {
+  member: Blob
+}
+
+@idempotent
+@http(method: "PUT", uri: "/{bucketName}/{partitionKey}", code: 204)
+operation InsertItem {
+  input: InsertItemInput
+}
+
+@input
+structure InsertItemInput with [KeySelector] {}
+
+//operation DeleteItem {
+//  input: String
+//  output: String
+//}
+
+//operation PollItem {
+//  input: String
+//  output: String
+//}
+
+//operation ReadIndex {
+//  input: String
+//  output: String
+//}
+
+//operation InsertBatch {
+//  input: String
+//  output: String
+//}
+
+//operation DeleteBatch {
+//  input: String
+//  output: String
+//}
+
+//operation PollRange {
+//  input: String
+//  output: String
+//}
diff --git a/smithy-build.json b/smithy-build.json
new file mode 100644
index 00000000..29de8a18
--- /dev/null
+++ b/smithy-build.json
@@ -0,0 +1,8 @@
+{
+    "version": "1.0",
+    "plugins": {
+        "openapi": {
+            "service": "org.deuxfleurs.garage.k2v#K2V"
+        }
+    }
+}