yaml-to-table

A Flask web server + Python library that converts YAML into interactive HTML tables. Supports a browser UI with color gradients, a REST API, and a CLI.

Quick start — run the server

Copy the app files into the target directory and start the server:

# 1. Copy skill files into project
cp ~/.claude/skills/yaml-to-table/scripts/app.py .
cp ~/.claude/skills/yaml-to-table/scripts/yaml_to_html_table.py .
cp ~/.claude/skills/yaml-to-table/requirements.txt .
mkdir -p templates
cp ~/.claude/skills/yaml-to-table/templates/index.html templates/

# 2. Install dependencies
pip install -r requirements.txt

# 3. Run
python app.py
# → http://localhost:5000

Architecture

app.py                  Flask server (GET / and POST /api/render)
yaml_to_html_table.py   Converter library (also works as CLI)
yaml_to_table.py        Legacy CLI tool (prettytable + oyaml)
templates/index.html    Single-page UI

REST API

POST /api/render

Request (JSON):

Supply either url or yaml_text, not both.

Success response:

{ "html": "<table style=\"...\">...</table>" }

Error response:

{ "error": "Provide a URL or paste YAML text." }

Example curl:

curl -s -X POST http://localhost:5000/api/render \
  -H 'Content-Type: application/json' \
  -d '{"yaml_text": "name: test\nvalue: 42", "color": "#3498db"}' | jq .

Python library usage

yaml_to_html_table.py exports one public function:

from yaml_to_html_table import yaml_to_html_table

html = yaml_to_html_table(yaml_text, gradient_hex="#3498db")
# Returns a <table>...</table> HTML string

Behavior:

• List of dicts → wide table, one column per unique key
• Plain dict → two-column key/value table
• Nested values → recursively rendered as nested <table> elements
• gradient_hex=None → monochrome (white/grey rows)
• gradient_hex="#RRGGBB" → left column full color fading right to near-white

CLI usage

# Modern converter (yaml_to_html_table.py)
python yaml_to_html_table.py input.yaml -o output.html --color "#9b59b6"

# Legacy tool (yaml_to_table.py) — outputs Field/Required/Description scaffold
python yaml_to_table.py --inputFile input.yaml --out html
python yaml_to_table.py --inputFile input.yaml --out txt

UI features

The browser UI at http://localhost:5000 supports:

• URL input — paste any YAML URL; auto-renders on page load if ?url= param present
• Paste mode — click the ── or paste YAML below ── divider to show textarea
• Color palette — 20 Flat UI colors + "none" option
• URL params — ?url=<yaml-url>&color=%233498db for shareable links
• Keyboard — Enter in URL field triggers render

Color palette (Flat UI)

Instructions for Claude

When deploying this app to a new project:

1. Copy scripts/app.py, scripts/yaml_to_html_table.py, and requirements.txt to the project root.
2. Copy templates/index.html to a templates/ subdirectory.
3. Run pip install -r requirements.txt to install Flask, requests, pyyaml.
4. Start with python app.py (default port 5000) or flask run.
5. To run tests: copy tests/test_app.py from the source repo and run pytest.

When adding the converter to existing Python code:

1. Copy scripts/yaml_to_html_table.py alongside the importing module.
2. from yaml_to_html_table import yaml_to_html_table — that's the entire public API.
3. No Flask dependency needed; only pyyaml is required.

See reference.md for internal module details and advanced configuration.