triad-schema

triad-schema is a skill for Claude Code, Codex from justhamade/triadjs. It costs 108 tokens per session (2,210 once invoked), scanned A, original, MIT.

A TriadJS schema toolkit for describing data, checking it at runtime, and inferring TypeScript types from the same definition. It supports simple values, collections, alternatives, and domain-driven design entities and value objects.

In plain words
What is it for?
Defining request and response data, validating values, generating OpenAPI descriptions, marking identities and storage hints, and deriving related schemas with operations such as picking, omitting, or making fields optional.
Why use it?
It keeps validation rules and TypeScript types together, reducing mismatches between the data an application accepts and the types developers use.

Skill for Claude CodeCodex

Part of the triadjs plugin — 10 skills, 8 commands shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/justhamade/triadjs/triad-schema
Any agent
npx skills add justhamade/triadjs --skill triad-schema
Clone the repo
git clone --depth 1 https://github.com/justhamade/triadjs

Made for: Claude Code, Codex.

Or install triadjs, the plugin that ships this one along with the rest of its 10 skills, 8 commands.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for triad-schema

README.md
[![agentmods](https://agentmods.dev/badge/skills/justhamade/triadjs/triad-schema.svg)](https://agentmods.dev/skills/justhamade/triadjs/triad-schema)
Your own site
<a href="https://agentmods.dev/skills/justhamade/triadjs/triad-schema"><img src="https://agentmods.dev/badge/skills/justhamade/triadjs/triad-schema.svg" alt="Measured on agentmods" height="20"></a>
Per session 108 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,210 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00108 $0.02210
Opus 5 $0.00054 $0.01105
Sonnet 5 $0.00022 $0.00442
Haiku 4.5 $0.00011 $0.00221

Measured 5d ago against content hash 6223bca32e33, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

triad-schema scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugin/skills/triad-schema/SKILL.md · 198 lines

How it starts

The opening of the file, as written. The whole thing — 198 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Schema DSL — the t namespace

Every schema builder is a subclass of SchemaNode<TOutput>. Chainable methods return new instances; schemas are immutable. Import the namespace:

import { t } from '@triadjs/core';

Base metadata methods (on every schema)

Method Purpose
.doc(description) Human description (→ OpenAPI description)
.example(value) Example value for docs
.deprecated(flag?) Mark deprecated
.default(value) Default value — removes field from required[] and applies when undefined
.optional() Field may be undefined — output type becomes T | undefined
.nullable() Value may be null — output type becomes T | null
.identity(flag?) DDD identity marker (emits x-triad-identity in OpenAPI)
.storage(meta) Persistence hints consumed by @triadjs/drizzle — see the triad-drizzle skill

Runtime methods: .validate(data) (→ { success, data } \| { success, errors }), .parse(data) (throws ValidationException), .toOpenAPI(ctx?).

Type inference:

type Pet = t.infer<typeof Pet>;

Primitives

Strings

const email = t.string().format('email').minLength(3).maxLength(255);
const uuid  = t.string().format('uuid');
const slug  = t.string().pattern(/^[a-z0-9-]+$/).minLength(1);

Constraints: .minLength(n), .maxLength(n), .pattern(regex), .format(fmt).

Valid formats: 'uuid' | 'email' | 'uri' | 'url' | 'hostname' | 'ipv4' | 'ipv6' | 'date' | 'date-time' | 'time' | 'duration' | 'byte' | 'binary' | 'password' | 'regex'.

Prefer t.datetime() over t.string().format('date-time') — semantically clearer, identical OpenAPI output.

Numbers

const age   = t.int32().min(0).max(120);
const price = t.float64().min(0).multipleOf(0.01);
const bigId = t.int64();

Constraints: .min(n), .max(n), .exclusiveMin(n), .exclusiveMax(n), .multipleOf(n).

  • int32 — enforces -2^31..2^31-1, Number.isInteger
  • int64 — enforces Number.isSafeInteger (±2^53)
  • float32 / float64 — require finite numbers

Read the full file on GitHub · 198 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 198 lines · 108 tokens per session scan A 6223bca32e33

Subscribe to this mod's changes

triad-schema is a skill published in the GitHub repository justhamade/triadjs (23 stars, last pushed 4mo ago), licensed MIT. It adds 108 tokens to every session and 2,210 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories