TypeError: Cannot read properties of undefined (reading '_zod') with Zod 3.25.76

[Batsirai]

Bug Description

When using @convex-dev/agent@0.3.2 with zod@3.25.76, any agent with tools fails to run with:

TypeError: Cannot read properties of undefined (reading '_zod')

Environment

• @convex-dev/agent: 0.3.2
• zod: 3.25.76
• ai: 5.0.110
• @ai-sdk/provider-utils: 3.0.18
• convex: 1.29.3

Reproduction

1. Create an agent with any tool using createTool:

import { Agent, createTool } from "@convex-dev/agent";
import { z } from "zod";

const myTool = createTool({
  description: "Test tool",
  args: z.object({
    input: z.string(),
  }),
  handler: async (ctx, args) => {
    return "result";
  },
});

export const myAgent = new Agent(components.agent, {
  name: "Test Agent",
  tools: { myTool },
  // ...
});

2. Try to run the agent
3. Error occurs during tool schema validation

Root Cause

The @ai-sdk/provider-utils package checks for Zod 4 schemas using:

function isZod4Schema(zodSchema) {
  return "_zod" in zodSchema;
}

However, the zodSchema parameter is undefined when it reaches this check, causing the error.

Expected Behavior

Agents with tools should work with Zod 3.25.76, which is listed as a supported peer dependency in @ai-sdk/provider-utils.

Workaround Attempted

• Tried zod@3.22.4 - bundling fails (missing zod/v4 export)
• Tried zod@3.23.8 - same _zod error
• Tried @convex-dev/agent@0.5.0-alpha.1 - same error
• Tried zod/v3 import - Convex bundler doesn't resolve it correctly

[ianmacartney]

Try importing from zod/v4?

…

On Thu, Dec 11, 2025 at 5:43 AM Batsirai Chada ***@***.***> wrote: *Batsirai* created an issue (get-convex/agent#196) <#196> Bug Description When using @***@***.*** with ***@***.***, any agent with tools fails to run with: TypeError: Cannot read properties of undefined (reading '_zod') Environment - @convex-dev/agent: 0.3.2 - zod: 3.25.76 - ai: 5.0.110 - @ai-sdk/provider-utils: 3.0.18 - convex: 1.29.3 Reproduction 1. Create an agent with any tool using createTool: import { Agent, createTool } from ***@***.***/agent";import { z } from "zod"; const myTool = createTool({ description: "Test tool", args: z.object({ input: z.string(), }), handler: async (ctx, args) => { return "result"; },}); export const myAgent = new Agent(components.agent, { name: "Test Agent", tools: { myTool }, // ...}); 2. Try to run the agent 3. Error occurs during tool schema validation Root Cause The @ai-sdk/provider-utils package checks for Zod 4 schemas using: function isZod4Schema(zodSchema) { return "_zod" in zodSchema;} However, the zodSchema parameter is undefined when it reaches this check, causing the error. Expected Behavior Agents with tools should work with Zod 3.25.76, which is listed as a supported peer dependency in @ai-sdk/provider-utils. Workaround Attempted - Tried ***@***.*** - bundling fails (missing zod/v4 export) - Tried ***@***.*** - same _zod error - Tried @***@***.*** - same error - Tried zod/v3 import - Convex bundler doesn't resolve it correctly — Reply to this email directly, view it on GitHub <#196>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AACZQW4JUUYQBNNG5BAEOJD4BFYJXAVCNFSM6AAAAACOXRWMJ2VHI2DSMVQWIX3LMV43ASLTON2WKOZTG4YTSNBWHEZDMNY> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[ianmacartney]

A likely culprit here is circular imports. you can debug with npx madge convex/ --extensions ts --exclude api.d.ts --circular

…

On Thu, Dec 11, 2025 at 12:56 PM Ian Macartney ***@***.***> wrote: Try importing from zod/v4? On Thu, Dec 11, 2025 at 5:43 AM Batsirai Chada ***@***.***> wrote: > *Batsirai* created an issue (get-convex/agent#196) > <#196> > Bug Description > > When using @***@***.*** with ***@***.***, any agent with > tools fails to run with: > > TypeError: Cannot read properties of undefined (reading '_zod') > > Environment > > - @convex-dev/agent: 0.3.2 > - zod: 3.25.76 > - ai: 5.0.110 > - @ai-sdk/provider-utils: 3.0.18 > - convex: 1.29.3 > > Reproduction > > 1. Create an agent with any tool using createTool: > > import { Agent, createTool } from ***@***.***/agent";import { z } from "zod"; > const myTool = createTool({ > description: "Test tool", > args: z.object({ > input: z.string(), > }), > handler: async (ctx, args) => { > return "result"; > },}); > export const myAgent = new Agent(components.agent, { > name: "Test Agent", > tools: { myTool }, > // ...}); > > > 2. Try to run the agent > 3. Error occurs during tool schema validation > > Root Cause > > The @ai-sdk/provider-utils package checks for Zod 4 schemas using: > > function isZod4Schema(zodSchema) { > return "_zod" in zodSchema;} > > However, the zodSchema parameter is undefined when it reaches this > check, causing the error. > Expected Behavior > > Agents with tools should work with Zod 3.25.76, which is listed as a > supported peer dependency in @ai-sdk/provider-utils. > Workaround Attempted > > - Tried ***@***.*** - bundling fails (missing zod/v4 export) > - Tried ***@***.*** - same _zod error > - Tried @***@***.*** - same error > - Tried zod/v3 import - Convex bundler doesn't resolve it correctly > > — > Reply to this email directly, view it on GitHub > <#196>, or unsubscribe > <https://github.com/notifications/unsubscribe-auth/AACZQW4JUUYQBNNG5BAEOJD4BFYJXAVCNFSM6AAAAACOXRWMJ2VHI2DSMVQWIX3LMV43ASLTON2WKOZTG4YTSNBWHEZDMNY> > . > You are receiving this because you are subscribed to this thread.Message > ID: ***@***.***> >