Getting Started

Chart-Output generates pixel-perfect PNG, JPEG, SVG, WebP, and PDF charts via a simple REST API. Use it for emails, PDFs, bots, and automated reports.

Authentication

Anonymous requests (no Authorization header) return 200 at starter plan limits — 401 only fires when an Authorization header is present but invalid. You can also authenticate with a Bearer token or query-string key for higher quotas.

To track usage and access higher quotas, authenticate using one of:

API Key (Bearer header) – Create one from the API Keys page in your dashboard. Format: pk_live_... or pk_test_...
API Key (query parameter) – Pass ?key=pk_live_... or ?apiKey=pk_live_... in the URL. Required for <img src="..."> email embeds since browsers cannot send headers with image requests.
Session JWT – When logged in via the dashboard, your session token is used automatically for same-origin requests.

text

Authorization: Bearer pk_live_YOUR_API_KEY

Your First Render

Send a POST request to /api/v1/render with a chart specification:

bash

curl -X POST https://chart-output.com/api/v1/render \
  -H "Authorization: Bearer pk_live_YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "type": "line",
    "width": 800,
    "height": 400,
    "format": "png",
    "data": {
      "labels": ["Jan", "Feb", "Mar"],
      "datasets": [{
        "label": "Revenue",
        "data": [12000, 15000, 18000]
      }]
    }
  }' --output chart.png

The response is the raw image bytes. Check the response headers for metadata:

X-Render-Time-Ms – Render latency in milliseconds
X-Cache – HIT or MISS when Redis caching is enabled
X-Request-Id – Request ID for debugging and support

Next Steps

Quick Start – Your first chart in 5 minutes with curl, Node.js, and Python
API Reference – Full endpoint documentation
Chart Specifications – Types, formats, and options
Card Composition – Headers, KPI strips, footers, and full card layouts
Templates – 16 pre-built chart templates