json-parser

A tool for reading, checking, formatting, and transforming JSON, a common text format for structured data. It can also compare the data with a JSON Schema, which describes the fields and types it should contain.

In plain words
What is it for?
It helps validate JSON, pretty-print it, inspect its structure, extract fields with JSONPath, and convert it to CSV or YAML.
Why use it?
It finds malformed data and schema mismatches before the data is used by another program.

Skill for Claude CodeCodex

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/maxvaega/skillkit/json-parser
Any agent
npx skills add maxvaega/skillkit --skill json-parser
Clone the repo
git clone --depth 1 https://github.com/maxvaega/skillkit

Made for: Claude Code, Codex.

Per session 11 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 169 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 $0.00011 $0.00169
Opus 5 $0.00005 $0.00084
Sonnet 5 $0.00002 $0.00034
Haiku 4.5 $0.00001 $0.00017

Measured yesterday against content hash ec397adb7bb3, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

json-parser 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 yesterday.

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.

examples/skills/example-plugin/skills/json-parser/SKILL.md · 38 lines

What it actually says

JSON Parser Skill

You are a JSON data validation assistant from the example-plugin.

Capabilities

  • Parse and pretty-print JSON data
  • Validate against JSON Schema
  • Detect malformed JSON
  • Extract specific fields using JSONPath
  • Convert to other formats (CSV, YAML)

Usage

To parse JSON data, provide the file path or raw JSON as an argument:

Arguments: $ARGUMENTS

Output Format

The parser will provide:

  • Validation status (valid/invalid)
  • Structure overview (depth, object count)
  • Schema compliance report (if schema provided)
  • Extracted values (if JSONPath provided)

Example

Input: config.json Output: Validated JSON structure with compliance report

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. yesterday First seen · 38 lines · 11 tokens per session scan A ec397adb7bb3

Subscribe to this mod's changes

json-parser is a skill published in the GitHub repository maxvaega/skillkit (146 stars, last pushed 7mo ago), licensed MIT. It adds 11 tokens to every session and 169 once invoked, about $0.0001 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