[JS] Genkit flows failing with zod schema

[sdk1990]

Describe the bug
I have configured Genkit to be working with Cloud Functions using the onFlow wrapper. When running a flow from Genkit Tools UI I receive the following error:
Cannot destructure property 'shape' of 'this._getCached(...)' as it is undefined.

To Reproduce
Init Genkit:

/**
 * Configure the Genkit SDK.
 * @see https://firebase.google.com/docs/genkit/get-started
 */
export function initGenkit(apiKey: string) {
	configureGenkit({
		plugins: [
			// Load the Firebase plugin, which provides integrations with several
			// Firebase services.
			firebase({ projectId }),
			// Load the Google AI plugin. You can optionally specify your API key
			// by passing in a config object; if you don't, the Google AI plugin uses
			// the value from the GOOGLE_GENAI_API_KEY environment variable, which is
			// the recommended practice.
			googleAI({ apiKey }),
			dotprompt(),
		],
		// Log debug output to tbe console.
		logLevel: 'debug',
		// Perform OpenTelemetry instrumentation and enable trace collection.
		enableTracingAndMetrics: true,
		flowStateStore: 'firebase',
		traceStore: 'firebase',
		telemetry: {
			instrumentation: 'firebase',
			logger: 'firebase',
		},
	});
}

Zod schema's:

import { defineSchema } from '@genkit-ai/core';
import { z } from '@genkit-ai/core/schema';

import { dietaryRestrictions } from '../../types/nutrition';

export const nutritionGoalInputSchema = defineSchema(
	'NutritionGoalInputSchema',
	z.object({
		age: z
			.number()
			.min(0, 'Age must be a non-negative number.')
			.describe('The age of the individual in years. Must be a non-negative number.'),
		gender: z.enum(['female', 'male']).describe('The biological gender of the individual, either "female" or "male".'),
		weightKg: z
			.number()
			.min(0, 'Weight must be a non-negative number.')
			.describe('The body weight of the individual in kilograms. Must be a non-negative number.'),
		lengthCm: z
			.number()
			.min(0, 'Height must be a non-negative number.')
			.describe('The height of the individual in centimeters. Must be a non-negative number.'),
		activityLevel: z
			.enum(['extra_active', 'very_active', 'moderately_active', 'lightly_active', 'sedentary'])
			.describe(
				'The general activity level (Physical Activity Level) of the individual throughout the day excluding formal exercise."'
			),
		dietaryGoals: z.object({
			goalType: z
				.enum(['fat_loss', 'muscle_gain'])
				.describe(
					'The primary dietary objective of the individual. Options are: "fat_loss" for reducing body fat percentage, and "muscle_gain" for increasing muscle mass.'
				),
		}),
		dietaryRestrictions: z
			.array(z.union([z.enum(dietaryRestrictions), z.string()]))
			.optional()
			.describe(
				'A list of dietary restrictions or preferences for the individual. These can include specific dietary patterns like "vegan", "vegetarian", "kosher" or "halal"'
			),
	})
);

export type NutritionGoalInputSchema = typeof nutritionGoalInputSchema;

export const nutritionGoalOutputSchema = defineSchema(
	'NutritionGoalOutputSchema',
	z.object({
		specs: z.object({
			calories: z
				.number()
				.min(0, 'Calories must be a non-negative number.')
				.describe(
					"The total estimated energy requirement for the individual in kilocalories (kcal) per day. This is calculated based on the individual's activity level, age, weight, height, gender, and dietary goals."
				),
			protein: z
				.number()
				.min(0, 'Protein must be a non-negative number.')
				.describe(
					'The total daily recommended protein intake in grams (g) for the individual, calculated based on body weight, activity level, and dietary objectives.'
				),
			fat: z
				.number()
				.min(0, 'Fat must be a non-negative number.')
				.describe(
					'The total daily recommended fat intake in grams (g) for the individual, derived from the percentage of total calories allocated to dietary fat based on activity level and goals.'
				),
			carbs: z
				.number()
				.min(0, 'Carbohydrates must be a non-negative number.')
				.describe(
					'The total daily recommended carbohydrate intake in grams (g) for the individual, derived from the remaining calories after accounting for protein and fat, adjusted for dietary preferences and activity level.'
				),
		}),
	})
);

export type NutritionGoalOutputSchema = typeof nutritionGoalOutputSchema;

Flow:

const nutritionGoalPrompt = promptRef('nutrition/01-nutrition-goal');

const nutritionGoalFlow = onFlow(
	{
		name: '01-nutritionGoal',
		authPolicy,
		inputSchema: nutritionGoalInputSchema,
		outputSchema: nutritionGoalOutputSchema,
		httpsOptions: httpsOptions(),
	},
	async (input) => {
		info('[01-nutritionGoalFlow] Start');

		try {
			const result = await nutritionGoalPrompt.generate<NutritionGoalOutputSchema>({ input });

			info('[01-nutritionGoalFlow] - ✅ Success');

			return result.output();
		} catch (err) {
			error('[01-nutritionGoalFlow] ❌ Error', err);
			throw err;
		}
	}
);

Expected behavior
I expected the flow to run as desired. When I test the prompt from the Genkit Tools UI, it works as expected.

Screenshots
Failing flow:

Runtime (please complete the following information):

• OS: MacOS
• Version 15

** Node version

• v20.17.0

Additional context
Using Cloud Functions 2nd gen with local emulators.

[odbol]

+1 I'm also running into this

[odbol]

Strangely, I was able to fix it by changing line 1831 in node_modules/zod/lib/types.js:

    _getCached() {
        if (this._cached != null) // note using non-strict equality fixes it somehow
            return this._cached;
        const shape = this._def.shape();
        const keys = util_1.util.objectKeys(shape);
        return (this._cached = { shape, keys });
    }

[pavelgj]

This is an odd issue. Feel like zod bug... I'm trying to come up with a narrower repro.

[pavelgj]

This seems to work fine

import { z } from 'zod';

export const nutritionGoalInputSchema = z.object({
  age: z
    .number()
    .min(0, 'Age must be a non-negative number.')
    .describe(
      'The age of the individual in years. Must be a non-negative number.'
    ),
  gender: z
    .enum(['female', 'male'])
    .describe(
      'The biological gender of the individual, either "female" or "male".'
    ),
  weightKg: z
    .number()
    .min(0, 'Weight must be a non-negative number.')
    .describe(
      'The body weight of the individual in kilograms. Must be a non-negative number.'
    ),
  lengthCm: z
    .number()
    .min(0, 'Height must be a non-negative number.')
    .describe(
      'The height of the individual in centimeters. Must be a non-negative number.'
    ),
  activityLevel: z
    .enum([
      'extra_active',
      'very_active',
      'moderately_active',
      'lightly_active',
      'sedentary',
    ])
    .describe(
      'The general activity level (Physical Activity Level) of the individual throughout the day excluding formal exercise."'
    ),
  dietaryGoals: z.object({
    goalType: z
      .enum(['fat_loss', 'muscle_gain'])
      .describe(
        'The primary dietary objective of the individual. Options are: "fat_loss" for reducing body fat percentage, and "muscle_gain" for increasing muscle mass.'
      ),
  }),
  dietaryRestrictions: z
    .array(z.union([z.enum(['1', '2', '3']), z.string()]))
    .optional()
    .describe(
      'A list of dietary restrictions or preferences for the individual. These can include specific dietary patterns like "vegan", "vegetarian", "kosher" or "halal"'
    ),
});

export const nutritionGoalOutputSchema = z.object({
  specs: z.object({
    calories: z
      .number()
      .min(0, 'Calories must be a non-negative number.')
      .describe(
        "The total estimated energy requirement for the individual in kilocalories (kcal) per day. This is calculated based on the individual's activity level, age, weight, height, gender, and dietary goals."
      ),
    protein: z
      .number()
      .min(0, 'Protein must be a non-negative number.')
      .describe(
        'The total daily recommended protein intake in grams (g) for the individual, calculated based on body weight, activity level, and dietary objectives.'
      ),
    fat: z
      .number()
      .min(0, 'Fat must be a non-negative number.')
      .describe(
        'The total daily recommended fat intake in grams (g) for the individual, derived from the percentage of total calories allocated to dietary fat based on activity level and goals.'
      ),
    carbs: z
      .number()
      .min(0, 'Carbohydrates must be a non-negative number.')
      .describe(
        'The total daily recommended carbohydrate intake in grams (g) for the individual, derived from the remaining calories after accounting for protein and fat, adjusted for dietary preferences and activity level.'
      ),
  }),
});

console.log(
  nutritionGoalInputSchema.parse({
    age: 33,
    gender: 'female',
    weightKg: 88,
    lengthCm: 33,
    activityLevel: 'sedentary',
    dietaryGoals: {
      goalType: 'muscle_gain',
    },
    dietaryRestrictions: ['1'],
  } as z.infer<typeof nutritionGoalInputSchema>)
);

console.log(
  nutritionGoalOutputSchema.parse({
    specs: {
      calories: 123,
      carbs: 2344,
      fat: 343,
      protein: 233
    },
    
  } as z.infer<typeof nutritionGoalOutputSchema>)
);

[dario-digregorio]

I had the same issue and needed a fix. I used patch-package to create a patch for this and I am waiting until zod merges the PR.

[jiahaog]

Here's a smaller repro:

EDIT: See https://github.com/jiahaog/genkit-zod-schema-repro for the complete repro.

Seems like the issue is with the zod schema being reused in defineSchema, and in defineFlow directly. See the above commented code for a workaround.

[gspencergoog]

This can be temporarily fixed locally with a tiny patch to zod, if waiting for colinhacks/zod#3841 to land isn't a possibility.

Here's the patch (you can apply automatically if you install patch-package and make this modification to zod and run npx patch-package zod):

diff --git a/node_modules/zod/lib/types.js b/node_modules/zod/lib/types.js
index 731ffd8..86d5a14 100644
--- a/node_modules/zod/lib/types.js
+++ b/node_modules/zod/lib/types.js
@@ -1973,7 +1973,7 @@ class ZodObject extends ZodType {
         this.augment = this.extend;
     }
     _getCached() {
-        if (this._cached !== null)
+        if (this._cached != null)
             return this._cached;
         const shape = this._def.shape();
         const keys = util_1.util.objectKeys(shape);

[pavelgj]

Here's a smaller repro:

import { z } from "genkit";
import { googleAI } from "@genkit-ai/googleai";
import { genkit } from "genkit";

export const ai = genkit({
promptDir: "./prompts",
plugins: [googleAI()],
});

const debugZodSchema = z.object({
foo: z.string(),
});

ai.defineSchema("debugZodSchema", debugZodSchema);
// Commenting the previous line out, or replacing it with the following
// fixes the error.

// ai.defineSchema(
// "debugZodSchema",
// z.object({
// foo: z.string(),
// })
// );

export const debugZodInner = ai.defineFlow(
{
name: "debugZodInner",
inputSchema: debugZodSchema,
},
async (_) => {
return { foo: "bar" };
}
);

export const debugZod = ai.defineFlow(
{
name: "debugZod",
},
async function (________) {
return debugZodInner({ foo: "bar" });
}
);

ai.startFlowServer({
flows: [debugZod],
port: 3405,
});

$ curl -X POST "http://localhost:3405/debugZod"   -H "Content-Type: application/json"  -d '{}'

{"error":{"status":"INTERNAL","message":"Cannot destructure property 'shape' of 'this._getCached(...)' as it is undefined.","details":"TypeError: Cannot destructure property 'shape' of 'this._getCached(...)' as it is undefined.\n
...

Seems like the issue is with the zod schema being reused in defineSchema, and in defineFlow directly. See the above commented code for a workaround.

Not having any luck reproducing the error with the above code... could you please also share your package.json?

[pavelgj]

If someone could share zip with a repro I'd be eternally grateful!

[jiahaog]

Sorry for the noise. It turns out that both the code as well as a dotprompt file that uses schema declared in the code are necessary for the repro. I've created https://github.com/jiahaog/genkit-zod-schema-repro as a full repro, and edited my previous comment.