feat(genkit-tools): add /listValues endpoint to expose defaultModel

genkit-tools/common/src/manager/manager.ts

@@ -198,6 +198,44 @@ export class RuntimeManager {
     return response.data as Record<string, Action>;
   }
 
+  /**
+   * Retrieves all valuess.
+   */
+  async listValues(
+    input: apis.ListValuesRequest
+  ): Promise<Record<string, unknown>> {
+    const runtime = input.runtimeId
+      ? this.getRuntimeById(input.runtimeId)
+      : this.getMostRecentRuntime();
+    if (!runtime) {
+      throw new Error(
+        input?.runtimeId
+          ? `No runtime found with ID ${input.runtimeId}.`
+          : 'No runtimes found. Make sure your app is running using `genkit start -- ...`. See getting started documentation.'
+      );
+    }
+    try {
+      const response = await axios.get(
+        `${runtime.reflectionServerUrl}/api/values`,
+        {
+          params: {
+            type: input.type,
+          },
+        }
+      );
+      return response.data as Record<string, unknown>;
+    } catch (err) {
+      if ((err as AxiosError).response?.status === 404) {
+        return {};
+      } else if ((err as AxiosError).response?.status === 400) {
+        throw new GenkitToolsError(
+          `Bad request: ${(err as AxiosError).response?.data}`
+        );
+      }
+      this.httpErrorHandler(err as AxiosError, 'Error listing values.');
+    }
+  }
+
   /**
    * Runs an action.
    */

genkit-tools/common/src/server/router.ts

@@ -134,6 +134,13 @@ export const TOOLS_SERVER_ROUTER = (manager: RuntimeManager) =>
         return manager.listActions(input);
       }),
 
+    /** Retrieves all values. */
+    listValues: loggedProcedure
+      .input(apis.ListValuesRequestSchema)
+      .query(async ({ input }): Promise<Record<string, unknown>> => {
+        return manager.listValues(input);
+      }),
+
     /** Generate a .prompt file from messages and model config. */
     createPrompt: loggedProcedure
       .input(apis.CreatePromptRequestSchema)

genkit-tools/common/src/types/apis.ts

@@ -80,6 +80,22 @@ export const ListActionsRequestSchema = z
 
 export type ListActionsRequest = z.infer<typeof ListActionsRequestSchema>;
 
+export const ListValuesRequestSchema = z.object({
+  runtimeId: z
+    .string()
+    .optional()
+    .describe(
+      'ID of the Genkit runtime to run the action on. Typically $pid-$port.'
+    ),
+  type: z
+    .string()
+    .describe(
+      "The type of values to fetch. Currently only supports 'defaultModel'"
+    ),
+});
+
+export type ListValuesRequest = z.infer<typeof ListValuesRequestSchema>;
+
 export const RunActionRequestSchema = z.object({
   runtimeId: z
     .string()

js/core/src/reflection.ts

@@ -151,6 +151,30 @@ export class ReflectionServer {
       await this.stop();
     });
 
+    server.get('/api/values', async (req, response, next) => {
+      logger.debug('Fetching values.');
+      try {
+        const type = req.query.type;
+        if (!type) {
+          response.status(400).send('Query parameter "type" is required.');
+          return;
+        }
+        if (type !== 'defaultModel') {
+          response
+            .status(400)
+            .send(
+              `'type' ${type} is not supported. Only 'defaultModel' is supported`
+            );
+          return;
+        }
+        const values = await this.registry.listValues(type as string);
+        response.send(values);
+      } catch (err) {
+        const { message, stack } = err as Error;
+        next({ message, stack });
+      }
+    });
+
     server.get('/api/actions', async (_, response, next) => {
       logger.debug('Fetching actions.');
       try {

js/genkit/src/genkit.ts

@@ -25,6 +25,7 @@ import {
   generate,
   generateStream,
   loadPromptFolder,
+  modelRef,
   prompt,
   rerank,
   retrieve,
@@ -46,6 +47,7 @@ import {
   type GenerationCommonConfigSchema,
   type IndexerParams,
   type ModelArgument,
+  type ModelReference,
   type Part,
   type PromptConfig,
   type PromptGenerateOptions,
@@ -953,7 +955,7 @@ export class Genkit implements HasRegistry {
       this.registry.registerValue(
         'defaultModel',
         'defaultModel',
-        this.options.model
+        toModelRef(this.options.model)
       );
     }
     if (this.options.promptDir !== null) {
@@ -1086,3 +1088,22 @@ let disableReflectionApi = false;
 export function __disableReflectionApi() {
   disableReflectionApi = true;
 }
+
+/** Helper method to map ModelArgument to ModelReference */
+function toModelRef(
+  modelArg: ModelArgument<any> | undefined
+): ModelReference<any> | undefined {
+  if (modelArg === undefined) {
+    return undefined;
+  }
+  if (typeof modelArg === 'string') {
+    return modelRef({ name: modelArg });
+  }
+  if ((modelArg as ModelReference<any>).name) {
+    return modelArg as ModelReference<any>;
+  }
+  const modelAction = modelArg as ModelAction;
+  return modelRef({
+    name: modelAction.__action.name,
+  });
+}