Our review
Converts structured data files (JSON, YAML, CSV) into token-efficient formats to reduce token usage in LLM contexts.
Strengths
- Reduces tokens by 30-70% on structured data
- Supports multiple input formats (JSON, YAML, XML, CSV)
- Offers filtering, truncation, and format selection options
Limitations
- May lose some nested structure details if truncation is too aggressive
- Best for tabular or uniform data sets
- Not suitable if full data fidelity is required without any loss
When feeding large structured data into an LLM and aiming to minimize token costs.
If you need to preserve the complete original data structure with no information loss.
Security analysis
SafeThe skill is a data formatting utility that converts structured formats (JSON/YAML/XML/CSV) into token-efficient representations. It does not execute any destructive operations, exfiltrate data, or disable safety features. All actions are legitimate transformations, and no risky patterns like curl-pipe-shell or unexpected system modifications are present.
No concerns found
Examples
Convert this JSON file to TOON format to save tokens: llm-fmt data.jsonI have a large CSV file, convert it to TSV format for token efficiency: llm-fmt data.csv -f tsvAnalyze the best format for my JSON data: llm-fmt data.json --analyzename: llm-fmt description: Convert JSON/YAML/XML/CSV to token-efficient formats (30-70% savings) allowed-tools: Bash
llm-fmt
Reduces tokens by 30-70% for structured data in LLM contexts.
Usage
llm-fmt data.json # TOON output (default)
llm-fmt data.json -f tsv # TSV (best for tables, 60-75% savings)
llm-fmt data.json -f yaml # YAML (nested configs, 25-35%)
llm-fmt data.json --analyze # Compare all formats
Filtering & Truncation
llm-fmt data.json -i "users[*].name" # Extract paths
llm-fmt data.json --max-depth 3 # Limit nesting
llm-fmt data.json --max-items 50 # Limit arrays
llm-fmt data.json --max-string-length 200 # Limit strings
llm-fmt data.json --truncation-strategy tail # head|tail|balanced|sample
Format Guide
| Data | Format | Savings | |------|--------|---------| | Tables, uniform arrays | tsv | 60-75% | | Object arrays (API/logs) | toon | 45-60% | | Nested configs | yaml | 25-35% | | Mixed/complex | json | 10-15% |
Pipes
curl -s api.example.com/data | llm-fmt -f tsv
cat large.json | llm-fmt --max-items 100
Prompt Engineering
Data & AI
Prompt engineering best practices and templates to maximize AI outputs.
Data Visualization
Data & AI
Generates data visualizations and charts tailored to your data.
RAG Architecture Setup
Data & AI
Setup guide for RAG (Retrieval-Augmented Generation) architectures.