syn-json-diff

syn-json-diff is a skill for Claude Code, Codex from legendtkl/agentic-skill-router. It costs 33 tokens per session (152 once invoked), scanned A, original, MIT.

A tool for comparing two JSON documents and showing their structural differences.

In plain words
What is it for?
Use it to inspect changes between JSON files or check how data has changed between versions.
Why use it?
It makes added, removed, and changed data paths easier to find than comparing the files manually.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to inspect changes between JSON files or check how data has changed between versions.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/legendtkl/agentic-skill-router/syn-json-diff
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 legendtkl/agentic-skill-router --skill syn-json-diff
Clone the repo
git clone --depth 1 https://github.com/legendtkl/agentic-skill-router

Made for: Claude Code, Codex.

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 syn-json-diff

README.md
[![agentmods](https://agentmods.dev/badge/skills/legendtkl/agentic-skill-router/syn-json-diff/github.svg)](https://agentmods.dev/skills/legendtkl/agentic-skill-router/syn-json-diff)
Your own site
<a href="https://agentmods.dev/skills/legendtkl/agentic-skill-router/syn-json-diff"><img src="https://agentmods.dev/badge/skills/legendtkl/agentic-skill-router/syn-json-diff/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 syn-json-diff

Your own site · 80×15
<a href="https://agentmods.dev/skills/legendtkl/agentic-skill-router/syn-json-diff"><img src="https://agentmods.dev/badge/skills/legendtkl/agentic-skill-router/syn-json-diff.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 33 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 152 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 $0.00033 $0.00152
Opus 5 $0.00016 $0.00076
Sonnet 5 $0.00007 $0.00030
Haiku 4.5 $0.00003 $0.00015

Measured 9d ago against content hash 0d3817538028, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

syn-json-diff 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 9d 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.

experiments/dci-compare/synthetic-skills/syn-json-diff/SKILL.md · 23 lines

What it actually says

JSON data: diffing two JSON documents

When to use

Use this skill for diffing two JSON documents in JSON data. This skill specifically handles diffing two JSON documents and nothing else in the JSON data family.

Procedure

Compute a structural diff between two JSON documents and present added/removed/changed paths.

Notes

This is the JSON data skill dedicated to diffing two JSON documents. Sibling skills cover other JSON data capabilities; this one is the right choice only when the task is about diffing two JSON documents.

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. 9d ago First seen · 23 lines · 33 tokens per session scan A 0d3817538028

Subscribe to this mod's changes

syn-json-diff is a skill published in the GitHub repository legendtkl/agentic-skill-router (5 stars, last pushed 3mo ago), licensed MIT. It adds 33 tokens to every session and 152 once invoked, about $0.0002 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.

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