Zod and AI SDK

Background

The AI SDK allows users to use Zod 3, Zod 4, and Zod 4 mini schemas directly.

Incorrect internal implementations can lead to infinite recursion and OOM issues such as #7351.

Rules

For Zod 3 usage (only required in compatibility code, e.g. parsing):

• always use import * as z3 from "zod/v3";

For Zod 4 usage:

• always use import * as z4 from "zod/v4";
• always use z4.core.$ZodType

Future Work

• set up linter to ensure imports are correct

Related issues

• OOM bug report

References

• Zod library authors guide