Chart Splat

Generate beautiful charts via the Chart Splat API. Use when the user asks to create, generate, or visualize data as charts, graphs, or plots. Supports line,...

Generate beautiful charts from data using the Chart Splat API. Charts are rendered server-side with Chart.js and returned as PNG images.

Supported Chart Types

Type	Best For
line	Trends over time
bar	Comparing categories
pie	Parts of a whole
doughnut	Parts of a whole (with center space)
radar	Multivariate comparison
polarArea	Comparing categories with radial layout
candlestick	Financial/crypto OHLC price data
ohlc	Financial/crypto OHLC price data (bar variant)

Method 1: CLI (Preferred)

Use the chartsplat CLI via npx. No install required.

npx -y chartsplat-cli bar \
  --labels "Q1,Q2,Q3,Q4" \
  --data "50,75,60,90" \
  --title "Quarterly Revenue" \
  --color "#8b5cf6" \
  -o chart.png

CLI Options

Flag	Description
-l, --labels <csv>	Comma-separated labels
-d, --data <csv>	Comma-separated numeric values
-t, --title <text>	Chart title
--label <text>	Dataset label for legend
-c, --color <hex>	Background color
-w, --width <px>	Image width (default: 800)
--height <px>	Image height (default: 600)
-o, --output <file>	Output file path (default: chart.png)
--config <file>	JSON config file for complex charts

CLI Chart Commands

npx -y chartsplat-cli line -l "Mon,Tue,Wed,Thu,Fri" -d "100,200,150,300,250" -o line.png
npx -y chartsplat-cli bar -l "A,B,C" -d "10,20,30" -o bar.png
npx -y chartsplat-cli pie -l "Red,Blue,Green" -d "30,50,20" -o pie.png
npx -y chartsplat-cli doughnut -l "Yes,No,Maybe" -d "60,25,15" -o doughnut.png
npx -y chartsplat-cli radar -l "Speed,Power,Range,Durability,Precision" -d "80,90,70,85,95" -o radar.png
npx -y chartsplat-cli polararea -l "N,E,S,W" -d "40,30,50,20" -o polar.png
npx -y chartsplat-cli candlestick --config ohlc.json -o chart.png

Candlestick Charts

Candlestick and OHLC charts require a JSON config file since the data format is more complex than a simple CSV list. Use --config to provide a file with OHLC data points.

npx -y chartsplat-cli candlestick --config ohlc.json -o candlestick.png

Config format (ohlc.json):

{
  "type": "candlestick",
  "data": {
    "datasets": [{
      "label": "VVV Price",
      "data": [
        { "x": 1740441600000, "o": 4.23, "h": 4.80, "l": 4.10, "c": 4.45 },
        { "x": 1740528000000, "o": 4.45, "h": 5.50, "l": 4.30, "c": 5.34 },
        { "x": 1740614400000, "o": 5.34, "h": 6.20, "l": 5.10, "c": 5.97 }
      ]
    }]
  }
}

Each OHLC data point requires: x (numeric timestamp in ms, or a date string like "2025-02-25"), o (open), h (high), l (low), c (close).

Complex Charts via Config File

For multi-dataset or customized charts, write a JSON config file then pass it to the CLI:

npx -y chartsplat-cli bar --config chart-config.json -o chart.png

See examples/sample-charts.json for config file examples and references/api-reference.md for the full config schema.

Method 2: Helper Script

Use the bundled script for quick generation without installing the CLI:

node scripts/generate-chart.js bar "Q1,Q2,Q3,Q4" "50,75,60,90" "Revenue" chart.png

Or with a config file:

node scripts/generate-chart.js --config chart-config.json -o chart.png

Output Handling

• Charts are saved as PNG files to the specified output path
• Default output is chart.png in the current directory
• For messaging platforms (Discord, Slack), return the file path: MEDIA: /path/to/chart.png
• The CLI and helper script handle base64 decoding automatically

Error Handling

Error	Cause	Fix
API key required	Missing CHARTSPLAT_API_KEY	Set the env var in agent config
Invalid API key	Wrong or revoked key	Generate a new key at chartsplat.com/dashboard
Rate limit exceeded	Monthly quota reached	Upgrade plan or wait for reset
Invalid chart configuration	Bad request payload	Check that data.labels and data.datasets are present (candlestick/ohlc only require data.datasets)

Tips

• Always provide both labels and data arrays of the same length
• Use hex colors (e.g., #8b5cf6) for consistent styling
• For pie/doughnut charts, use an array of colors for backgroundColor to color each segment
• Default dimensions (800x600) work well for most uses; increase for presentations
• The --config flag accepts any valid Chart.js configuration for full customization