From 3499b3293d2915837cbba902f858435a0274bbed Mon Sep 17 00:00:00 2001
From: Pavel Jbanov <pavelj@google.com>
Date: Wed, 26 Feb 2025 16:00:51 -0500
Subject: [PATCH 1/3] chore(js/ai): expose /util/model-runner action for the
 dev ui

---
 js/ai/src/generate/action.ts | 36 +++++++++++++++++++++++++++++++++++-
 1 file changed, 35 insertions(+), 1 deletion(-)

diff --git a/js/ai/src/generate/action.ts b/js/ai/src/generate/action.ts
index 7e8065c42..c6658d2c5 100644
--- a/js/ai/src/generate/action.ts
+++ b/js/ai/src/generate/action.ts
@@ -20,6 +20,7 @@ import {
   GenkitError,
   getStreamingCallback,
   runWithStreamingCallback,
+  sentinelNoopStreamingCallback,
   stripUndefinedProps,
   z,
 } from '@genkit-ai/core';
@@ -69,8 +70,41 @@ export type GenerateAction = Action<
   typeof GenerateResponseChunkSchema
 >;
 
-/** Defines (registers) a utilty generate action. */
+/** Defines (registers) a utilty model runner action. */
 export function defineGenerateAction(registry: Registry): GenerateAction {
+  defineAction(
+    registry,
+    {
+      actionType: 'util',
+      name: 'model-runner',
+      inputSchema: z.object({
+        model: z.string().optional(),
+        request: GenerateRequestSchema,
+      }),
+      outputSchema: GenerateResponseSchema,
+      streamSchema: GenerateResponseChunkSchema,
+    },
+    async (input, { sendChunk }) => {
+      const modelName =
+        input.model ??
+        (await registry.lookupValue('defaultModel', 'defaultModel'));
+      const resolvedModel = await resolveModel(registry, modelName);
+      const modelAction = resolvedModel.modelAction;
+
+      // TODO: add this to action run options object, sentinelNoopStreamingCallback is not
+      // exported publicly.
+      const isStreaming = sendChunk !== sentinelNoopStreamingCallback;
+      const modelFn = () => modelAction(input.request);
+      return isStreaming
+        ? runWithStreamingCallback(
+            registry,
+            (c: GenerateResponseChunk) => sendChunk(c.toJSON ? c.toJSON() : c),
+            modelFn
+          )
+        : modelFn();
+    }
+  );
+
   return defineAction(
     registry,
     {

From dc9e09fe6a5de06d104e3f2634c89f73e6e6ff84 Mon Sep 17 00:00:00 2001
From: Pavel Jbanov <pavelj@google.com>
Date: Wed, 26 Feb 2025 16:02:35 -0500
Subject: [PATCH 2/3] comment

---
 js/ai/src/generate/action.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/js/ai/src/generate/action.ts b/js/ai/src/generate/action.ts
index c6658d2c5..2d1fbd303 100644
--- a/js/ai/src/generate/action.ts
+++ b/js/ai/src/generate/action.ts
@@ -70,7 +70,7 @@ export type GenerateAction = Action<
   typeof GenerateResponseChunkSchema
 >;
 
-/** Defines (registers) a utilty model runner action. */
+/** Defines (registers) a utilty generate actions. */
 export function defineGenerateAction(registry: Registry): GenerateAction {
   defineAction(
     registry,

From 4edb1182a376bf627a3b9d197cdf087c0860bc30 Mon Sep 17 00:00:00 2001
From: Pavel Jbanov <pavelj@google.com>
Date: Wed, 26 Feb 2025 16:06:37 -0500
Subject: [PATCH 3/3] Update js/ai/src/generate/action.ts

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
---
 js/ai/src/generate/action.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/js/ai/src/generate/action.ts b/js/ai/src/generate/action.ts
index 2d1fbd303..9646444e1 100644
--- a/js/ai/src/generate/action.ts
+++ b/js/ai/src/generate/action.ts
@@ -70,7 +70,7 @@ export type GenerateAction = Action<
   typeof GenerateResponseChunkSchema
 >;
 
-/** Defines (registers) a utilty generate actions. */
+/** Defines (registers) the generate and model-runner actions. */
 export function defineGenerateAction(registry: Registry): GenerateAction {
   defineAction(
     registry,