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.
npx agentmods add skills/curiouslearner/devkit/json-transformernpx skills add CuriousLearner/devkit --skill json-transformergit clone --depth 1 https://github.com/CuriousLearner/devkitWhat 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 | $0.00017 | $0.06422 |
| Opus 5 | $0.00009 | $0.03211 |
| Sonnet 5 | $0.00003 | $0.01284 |
| Haiku 4.5 | $0.00002 | $0.00642 |
Grade A, and why
json-transformer 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 2d 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.
How it starts
The opening of the file, as written. The whole thing — 1,042 lines — stays where its author put it; the contents beside it link to each section on GitHub.
JSON Transformer Skill
Transform, manipulate, and analyze JSON data structures with advanced operations.
Instructions
You are a JSON transformation expert. When invoked:
-
Parse and Validate JSON:
- Parse JSON from files, strings, or APIs
- Validate JSON structure and schema
- Handle malformed JSON gracefully
- Pretty-print and format JSON
- Detect and fix common JSON issues
-
Transform Data Structures:
- Reshape nested objects and arrays
- Flatten and unflatten structures
- Extract specific paths (JSONPath, JMESPath)
- Merge and combine JSON documents
- Filter and map data
-
Advanced Operations:
- Convert between JSON and other formats (CSV, YAML, XML)
- Apply transformations (jq-style operations)
- Query and search JSON data
- Diff and compare JSON documents
- Generate JSON from schemas
-
Data Manipulation:
- Add, update, delete properties
- Rename keys
- Convert data types
- Sort and deduplicate
- Calculate aggregate values
Usage Examples
@json-transformer data.json
@json-transformer --flatten
@json-transformer --path "users[*].email"
@json-transformer --merge file1.json file2.json
@json-transformer --to-csv data.json
@json-transformer --validate schema.json
Basic JSON Operations
Parsing and Writing
Python
import json
# Parse JSON string
data = json.loads('{"name": "John", "age": 30}')
# Parse from file
with open('data.json', 'r') as f:
data = json.load(f)
# Write JSON to file
with open('output.json', 'w') as f:
json.dump(data, f, indent=2)
# Pretty print
print(json.dumps(data, indent=2, sort_keys=True))
# Compact output
compact = json.dumps(data, separators=(',', ':'))
# Handle special types
from datetime import datetime
import decimal
def json_encoder(obj):
if isinstance(obj, datetime):
return obj.isoformat()
if isinstance(obj, decimal.Decimal):
return float(obj)
raise TypeError(f"Type {type(obj)} not serializable")
json.dumps(data, default=json_encoder)
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.
- 2d ago First seen · 1,042 lines · 17 tokens per session scan A 39251dc61b6d
json-transformer is a skill published in the GitHub repository CuriousLearner/devkit (27 stars, last pushed 10mo ago), licensed MIT. It adds 17 tokens to every session and 6,422 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.
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