zod schema validation 3.x

Parse at the boundary, read the failure, and let the schema be the type.

Written for 3.x, which is no longer revised. The verification date below is where this line stopped, not a date that will move again.

Other lines of this skill: 4.x (active, for zod@^4.0.0).

For: zod@3.25.76
Verified: 2026-09-07, 7 examples executed
Package: @modootoday/pmcp-zod-schema-validation@3.0.0

What it covers

Import and version boundary
Primitive schemas and parsing
Object schemas and inferred types
Coercion
Custom messages
Tuples and rest elements
Selective partial objects
Records
Async parsing
Common version and shape mistakes
Not covered

One example from this skill

This is the skill's own text, not a summary of it. It runs: that is what verifying means here.

import { z } from "zod";
import assert from "node:assert/strict";

const schema = z.string();

assert.equal(schema.parse("tuna"), "tuna");
assert.throws(() => schema.parse(12));

const valid = schema.safeParse("tuna");
assert.equal(valid.success, true);
if (valid.success) assert.equal(valid.data, "tuna");

const invalid = schema.safeParse(12);
assert.equal(invalid.success, false);

What it did in the sandbox

Verifying this skill meant installing the package and running code against it with no route out. Nothing was observed. The full ledger lists every package examined, including the ones that never became a skill.

Nothing observed is not a finding of safety. It means one run, under one policy, produced nothing to report.

Getting it

With a subscription:

npx -y @modootoday/pmcp login
npx -y @modootoday/pmcp install @modootoday/pmcp-zod-schema-validation

It installs as a dev dependency of your project, and the MCP server finds it there like any other skill.