Replace discriminatedUnion with simple object for Gemini models

.changeset/rich-avocados-grab.md

@@ -0,0 +1,5 @@
+---
+"agents-sdk": patch
+---
+
+Replace discriminatedUnion with simple object for Gemini models

examples/playground/src/agents/scheduler.ts

@@ -73,10 +73,10 @@ Input to parse: "${event.input}"`,
       }
       const schedule = await this.schedule(
         when.type === "scheduled"
-          ? when.date
+          ? when.date!
           : when.type === "delayed"
-            ? when.delayInSeconds
-            : when.cron,
+            ? when.delayInSeconds!
+            : when.cron!,
         "onTask",
         description
       );

packages/agents/evals/scheduling.eval.ts

@@ -12,6 +12,8 @@ import {
 
 const model = openai("gpt-4o");
 // const model = google("gemini-2.0-pro-exp-02-05");
+// const model = google("gemini-2.0-flash");
+// const model = google("gemini-1.5-pro");
 // const model = anthropic("claude-3-5-sonnet-20240620"); // also disable mode: "json"
 
 function assert(condition: unknown, message: string): asserts condition {
@@ -39,7 +41,7 @@ const getsDetail = createScorer<string, Schedule>({
           output.when.type === "scheduled",
           "Output is not a scheduled task"
         );
-        return output.when.date.getTime() === expected.when.date.getTime()
+        return output.when?.date?.getTime() === expected.when?.date?.getTime()
           ? 1
           : 0;
       }
@@ -323,18 +325,23 @@ evalite<string, Schedule>("Evals for scheduling", {
   },
   // The task to perform
   task: async (input) => {
-    const result = await generateObject({
-      model,
-      // mode: "json",
-      // schemaName: "task",
-      // schemaDescription: "A task to be scheduled",
-      schema: unstable_scheduleSchema, // <- the shape of the object that the scheduler expects
-      maxRetries: 5,
-      prompt: `${unstable_getSchedulePrompt({ date: new Date() })}
+    try {
+      const result = await generateObject({
+        model,
+        // mode: "json",
+        // schemaName: "task",
+        // schemaDescription: "A task to be scheduled",
+        schema: unstable_scheduleSchema, // <- the shape of the object that the scheduler expects
+        maxRetries: 5,
+        prompt: `${unstable_getSchedulePrompt({ date: new Date() })}
 
 Input to parse: "${input}"`,
-    });
-    return result.object;
+      });
+      return result.object;
+    } catch (error) {
+      console.error(error);
+      throw error;
+    }
   },
   scorers: [getsType, getsDetail, getsDescription],
 });

packages/agents/src/schedule.ts

@@ -54,29 +54,27 @@ Example outputs:
 
 export const unstable_scheduleSchema = z.object({
   description: z.string().describe("A description of the task"),
-  when: z.discriminatedUnion("type", [
-    z
-      .object({
-        type: z.literal("scheduled"),
-        date: z.coerce.date(),
-      })
-      .describe("A scheduled task for a given date and time"),
-    z
-      .object({
-        type: z.literal("delayed"),
-        delayInSeconds: z.number(),
-      })
-      .describe("A delayed task in seconds"),
-    z
-      .object({
-        type: z.literal("cron"),
-        cron: z.string(),
-      })
-      .describe("A cron pattern"),
-    z
-      .object({
-        type: z.literal("no-schedule"),
-      })
-      .describe("No timing information, just a description of the task"),
-  ]),
+  when: z.object({
+    type: z
+      .enum(["scheduled", "delayed", "cron", "no-schedule"])
+      .describe("The type of scheduling details"),
+    date: z.coerce
+      .date()
+      .optional()
+      .describe(
+        "execute task at the specified date and time (only use if the type is scheduled)"
+      ),
+    delayInSeconds: z
+      .number()
+      .optional()
+      .describe(
+        "execute task after a delay in seconds (only use if the type is delayed)"
+      ),
+    cron: z
+      .string()
+      .optional()
+      .describe(
+        "execute task on a recurring interval specified as cron syntax (only use if the type is cron)"
+      ),
+  }),
 });