What is the CoinGrader AI API?

The CoinGrader AI API is a REST API that provides AI-powered coin grade estimates from photographs. Submit coin images and receive Sheldon scale grades (1-70), confidence scores, and surface analysis. Used by auction houses, dealers, and marketplace platforms.

How accurate is the coin grading API?

The API achieves ±2 grade points accuracy with 95% confidence when provided with clear, well-lit photographs. Accuracy is comparable to experienced human graders for most coin types. The API returns a confidence score with each grade estimate.

Is there a free tier for the coin grading API?

Yes, the Developer tier is free and includes 10 grade estimates per month with basic support. This is ideal for testing and evaluation. Professional ($99/mo) and Enterprise ($399/mo) tiers offer higher volumes and additional features.

How It Works Features Pricing Blog FAQ

Enterprise-Ready REST API

Coin Grading API
Integrate AI Grading Into Your Platform

Add AI-powered coin grade estimates to your auction house, marketplace, or dealer platform. Simple REST API with instant results, batch processing, and 99.9% uptime.

Get Free API Key View API Pricing

<500msResponse Time

99.9%Uptime SLA

10M+Coins Graded

API Features

Everything you need to integrate AI coin grading

RESTful Endpoints

Simple JSON request/response format. Standard HTTP methods. Comprehensive error handling with clear status codes.

Instant Results

Grade estimates returned in under 500ms. Submit coin photos as base64 or URL. Real-time processing with no queue delays.

PCGS/NGC Standards

Grades on the Sheldon scale (1-70) aligned to PCGS and NGC standards. Confidence scores, surface analysis, and problem detection included.

Batch Processing

Grade multiple coins in a single API call. Ideal for dealers processing inventory or auction houses grading consignments.

Webhook Support

Async processing for large batches. Get notified via webhook when results are ready. Perfect for background processing workflows.

Comprehensive Docs

OpenAPI specification, code examples in Python, JavaScript, and cURL. Interactive API playground for testing. Dedicated developer support.

Simple Integration

Grade a coin in 3 lines of code

API Request Example

curl -X POST https://api.coingrader.ai/v1/grade \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "image_url": "https://example.com/coin-obverse.jpg",
    "coin_type": "morgan_dollar",
    "service_standard": "pcgs"
  }'

Response (200 OK)

{
  "grade": "MS-64",
  "grade_numeric": 64,
  "confidence": 0.92,
  "grade_range": { "low": "MS-63", "high": "MS-65" },
  "surface_analysis": {
    "luster": "strong_cartwheel",
    "marks": "few_minor",
    "strike": "above_average",
    "eye_appeal": "above_average"
  },
  "problems_detected": [],
  "estimated_value": {
    "raw": 45,
    "graded": 85,
    "currency": "USD"
  }
}

API Pricing

Start free, scale as you grow

Developer

Free

Perfect for testing and evaluation

10 grades/month
Single image per request
Grade + confidence score
Community support
API documentation access

Get Free Key

Professional

$99/mo

For dealers and small platforms

1,000 grades/month
Batch processing (up to 50)
Full surface analysis
Value estimates included
Priority email support

Start Professional

Enterprise

$399/mo

For auction houses and large platforms

Unlimited grades
Batch processing (unlimited)
Webhook notifications
99.9% uptime SLA
Dedicated support + onboarding

Contact Enterprise

Built For Your Industry

How businesses use the CoinGrader AI API

Auction Houses

Pre-screen consignments automatically. Provide grade estimates to consignors before official grading. Reduce submission of low-value coins. Save thousands in wasted grading fees.

Coin Dealers

Grade inventory at scale. Make data-driven buying decisions. Identify undergraded coins in bulk purchases. Integrate into your existing dealer workflow.

Marketplace Platforms

Add verified grade estimates to listings. Increase buyer confidence. Reduce returns and disputes. Differentiate your platform with AI-powered grading.

Insurance & Valuation

Automate coin collection valuations. Provide grade-based value estimates for insurance purposes. Process claims with objective AI analysis.

API FAQ

How accurate is the API?

The API achieves ±2 grade points accuracy with 95% confidence on clear, well-lit photographs. Each response includes a confidence score so you can set thresholds for your use case. Accuracy improves with better photo quality.

What coin types are supported?

The API supports all major U.S. coin types including Morgan dollars, Lincoln cents, Kennedy halves, Walking Liberty halves, Washington quarters, and more. World coin support is expanding. Contact us for specific coin type availability.

What are the rate limits?

Developer: 10 requests/month. Professional: 1,000/month (burst: 10/minute). Enterprise: Unlimited (burst: 100/minute). Need higher limits? Contact our sales team for custom plans.

What image formats are accepted?

JPEG, PNG, and WebP formats. Minimum resolution: 500x500px. Recommended: 1000x1000px or higher. Submit via base64 encoding in the request body or provide a publicly accessible URL. Both obverse and reverse photos recommended for best accuracy.

Is my data secure?

All API communication is encrypted via TLS 1.3. Images are processed and deleted within 24 hours unless you opt into storage. We do not share your data with third parties. Enterprise plans include custom data retention policies and SOC 2 compliance documentation.