What is using-metaschema-java?

Command-line guidance for metaschema-java, a tool that checks Metaschema definitions and data, creates XML or JSON schemas, and converts data between XML and JSON.

Use it to validate Metaschema files, check XML or JSON against a model, generate schemas, and convert files between XML and JSON.

It helps developers use the correct commands when working with Metaschema models and catch invalid definitions or content.

using-metaschema-java — Skill for Claude Code by metaschema-framework

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.

Any agent

npx skills add metaschema-framework/claude-plugins --skill using-metaschema-java

Clone the repo

git clone --depth 1 https://github.com/metaschema-framework/claude-plugins

Made for: Claude Code.

Or install metaschema-tools, the plugin that ships this one along with the rest of its 2 skills.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/metaschema-framework/claude-plugins/using-metaschema-java/github.svg)](https://agentmods.dev/skills/metaschema-framework/claude-plugins/using-metaschema-java)

Your own site

<a href="https://agentmods.dev/skills/metaschema-framework/claude-plugins/using-metaschema-java"><img src="https://agentmods.dev/badge/skills/metaschema-framework/claude-plugins/using-metaschema-java/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/metaschema-framework/claude-plugins/using-metaschema-java"><img src="https://agentmods.dev/badge/skills/metaschema-framework/claude-plugins/using-metaschema-java.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 22 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 511 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.

Model	Per session	Once invoked
Fable 5.1	$0.00022	$0.00511
Opus 5.5	$0.00009	$0.00204
Sonnet 5.5	$0.00004	$0.00102
Haiku 4.5	$0.00002	$0.00051

Measured 2mo ago against content hash ae9abda57578, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

using-metaschema-java 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 2mo 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/metaschema-tools/skills/using-metaschema-java/SKILL.md · 81 lines

How it starts

The opening of the file, as written. The whole thing — 81 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Using metaschema-java CLI

The metaschema-java CLI provides command-line tools for working with Metaschema modules.

→ For programmatic Java usage: See metaschema-java-library skill

Common Commands

Validate a Metaschema Module

metaschema-cli validate <metaschema-file>

Validates the Metaschema module syntax and structure.

Validate Content Against a Metaschema

metaschema-cli validate-content --metaschema <metaschema-file> <content-file>

Validates XML or JSON content against the constraints defined in a Metaschema module.

Generate XML Schema

metaschema-cli generate-schema --as xml <metaschema-file>

Generate JSON Schema

metaschema-cli generate-schema --as json <metaschema-file>

Convert Content Between Formats

metaschema-cli convert --metaschema <metaschema-file> --to xml <json-file>
metaschema-cli convert --metaschema <metaschema-file> --to json <xml-file>

Converts content between XML and JSON formats using the Metaschema as the model definition.

Common Options

Option	Description
`--as <format>`	Specify output format (xml, json)
`-o <file>`	Write output to file
`--help`	Show command help

Best Practices

Always validate Metaschema modules before generating schemas
Validate content against Metaschema constraints, not just schema
Use --help on any command to see available options

Troubleshooting

Issue	Solution
Validation errors	Check module imports and namespace declarations
Content validation failures	Review constraint violations in output
Schema generation issues	Verify all referenced modules are accessible
Conversion errors	Ensure source content is valid before converting

Task	Skill
CLI commands (you are here)	`using-metaschema-java`
Java library/API usage	`metaschema-java-library`
Understanding Metaschema	`metaschema-basics` (from `metaschema` plugin)

Read the full file on GitHub · 81 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.

2mo ago First seen · 81 lines · 22 tokens per session scan A ae9abda57578

Subscribe to this mod's changes

using-metaschema-java is a skill published in the GitHub repository metaschema-framework/claude-plugins (10 stars, last pushed 8mo ago), licensed CC0-1.0. It adds 22 tokens to every session and 511 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-08-31.

using-metaschema-java next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
using-metaschema-javametaschema-framework/claude-plugins	Skill	10	8mo ago	CC0-1.0	A	22	Claude Code
imagegenopenai/codex	Skill	134k	today	Apache-2.0	A	113	Codex
playwright-climicrosoft/playwright	Skill	100k	today	Apache-2.0	A	19	Claude Code
local-ai-agentsmicrosoft/ai-agents-for-beginners	Skill	79k	3d ago	MIT	A	200	Claude Code, Codex
browser-automationopenclaw/openclaw	Skill	394k	today	MIT	A	36	Claude Code
systematic-debuggingobra/superpowers	Skill	315k	6d ago	MIT	A	21	Claude Code
next-cache-components-adoptionvercel/next.js	Skill	143k	today	MIT	A	95	Claude Code