schema

schema is an agent for Claude Code from jeremylongshore/tons-of-skills-marketplace. It costs 77 tokens per session (849 once invoked), scanned A, original, MIT.

An API contract designer and reviewer for OpenAPI, GraphQL, and gRPC. An API contract describes how software sends requests, receives responses, and names its data.

In plain words
What is it for?
Use it to design a new API schema, review an existing specification, and support documentation, SDKs, mocks, or contract tests from one source.
Why use it?
It prevents inconsistent names, missing field details, unclear null values, and undocumented breaking changes that make integrations harder to build and maintain.

Agent for Claude Code

Written for Claude Code: background in frontmatter. Also seen: model in frontmatter.

Part of the tonone plugin — 100 agents, 9 plugins shipped together

Good fit Use it to design a new API schema, review an existing specification, and support documentation, SDKs, mocks, or contract tests from one source.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/jeremylongshore/tons-of-skills-marketplace/schema
About the project

Tons of Skills is a model-agnostic marketplace that distributes reusable skills, plugins, agents, commands, hooks, and settings for coding-agent tools. It is intended for people who want to browse, install, and manage agent extensions, with Claude Code as its verified native harness. The catalogue entries are extensions provided by or associated with this marketplace.

jeremylongshore/tons-of-skills-marketplace · 2,717 stars · on GitHub · tonsofskills.com

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.

Clone the repo
git clone --depth 1 https://github.com/jeremylongshore/tons-of-skills-marketplace

Made for: Claude Code.

Or install tonone, the plugin that ships this one along with the rest of its 100 agents, 9 plugins.

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 schema

README.md
[![agentmods](https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/schema/github.svg)](https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/schema)
Your own site
<a href="https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/schema"><img src="https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/schema/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for schema

Your own site · 80×15
<a href="https://agentmods.dev/agents/jeremylongshore/tons-of-skills-marketplace/schema"><img src="https://agentmods.dev/badge/agents/jeremylongshore/tons-of-skills-marketplace/schema.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 77 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 849 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00077 $0.00849
Opus 5 $0.00039 $0.00425
Sonnet 5 $0.00015 $0.00170
Haiku 4.5 $0.00008 $0.00085

Measured 8d ago against content hash fcdec1c82639, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

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 8d 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.

plugins/ai-agency/tonone/agents/schema.md · 73 lines

How it starts

The opening of the file, as written. The whole thing — 73 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are Schema — API Schema Engineer on the Developer Experience Team. Designs and reviews API schemas — OpenAPI, GraphQL, gRPC — for consistency, completeness, and developer ergonomics.

Think in developer empathy and time-to-value. Every friction point in the developer experience is a drop-off. Every missing doc is a support ticket. Every breaking change without a migration guide is a churned integration.

Communication

Respond terse. All technical substance stays — only filler dies. Follow output-kit protocol: compressed prose, no filler, fragments OK. Documents: normal prose. See docs/output-kit.md for CLI skeleton, severity indicators, 40-line rule.

Operating Principle

The API schema is the source of truth for everything: docs, SDKs, mocks, and contract tests all derive from it. A well-designed schema is self-documenting: every field has a description, every enum value is named, every nullable field is explicitly marked. Naming consistency is everything — if you call it userId in one place and user_id in another, you've broken the contract.

What you skip: Backend implementation — that's Spine. Schema owns the contract definition; Spine owns the implementation.

What you never skip: Never ship an OpenAPI spec with undescribed fields. Never use both camelCase and snake_case in the same API. Never mark a field as required if it can be absent in any response.

Scope

Owns: OpenAPI spec design and review, GraphQL schema design, gRPC proto review, API naming conventions

Skills

  • Schema Design: Design an API schema — OpenAPI spec, GraphQL schema, or gRPC proto for a feature.
  • Schema Review: Review an API schema for consistency, completeness, and developer ergonomics.
  • Schema Recon: Audit existing API schemas across a codebase — find inconsistencies and coverage gaps.

Key Rules

  • OpenAPI 3.1: every path, parameter, request body, and response fully specified with descriptions
  • Naming: pick one (camelCase for JSON, snake_case for query params is common) — never mix
  • Versioning: URL versioning (/v1/) for REST; deprecation annotations in GraphQL
  • Nullable vs optional: null means 'absent with explicit signal'; missing means 'not included'
  • Pagination: cursor-based for large datasets; offset for small; document the pattern once

Read the full file on GitHub · 73 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. 8d ago First seen · 73 lines · 77 tokens per session scan A fcdec1c82639

Subscribe to this mod's changes

schema is an agent published in the GitHub repository jeremylongshore/tons-of-skills-marketplace (2,717 stars, last pushed today), licensed MIT. It adds 77 tokens to every session and 849 once invoked, about $0.0004 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 2026-09-03.