Get card information and pricing by grader certificate number.

This endpoint performs a multi-step lookup:

1. Checks the persistent validated-certificate cache; queries GemRate only when that certificate has not been successfully retrieved before
2. Fetches card details from CardHedge using GemRate IDs
3. Fallback: if step 2 finds no card, matches the GemRate description against the AI card-match endpoint
4. Retrieves price history for the card at the specified grade, served from the synced card_prices table with upstream fallback for cards the sync does not cover

Related: to look up many certificates at once, use details-by-certs (card details only) or batch-prices-by-cert (one price estimate per cert instead of price history).

card_source reports how the card was resolved -- gemrate_id for the direct GemRate ID lookup, or card_match for the description fallback. When the fallback is used, match_confidence carries the AI match score (0-1); treat prices derived from a low-confidence match with care. Cards resolved via the card_match fallback have null category_group and set_type -- the matcher does not return those two fields.

Example curl:

# Default: 180 days of price history
curl -X POST -H "X-API-Key: your-api-key-here" \
     -H "Content-Type: application/json" \
     -d '{
       "cert": "76676185",
       "grader": "PSA"
     }' \
     "https://api.cardhedger.com/v1/cards/prices-by-cert"

# Custom: 30 days of price history
curl -X POST -H "X-API-Key: your-api-key-here" \
     -H "Content-Type: application/json" \
     -d '{
       "cert": "76676185",
       "grader": "PSA",
       "days": 30
     }' \
     "https://api.cardhedger.com/v1/cards/prices-by-cert"

Returns certificate info, card details, and price history (default: 180 days, max: 365 days).

Daily allowance of uncached lookups. The first time a certificate is looked up it needs a live call to our grading-data provider and draws on your account's daily allowance of such lookups; repeat lookups are served from cache and do not. See Rate limits in the API overview for your tier's allowance.

{
  "cert": "76676185",
  "days": 180,
  "grader": "PSA"
}

{
  "card": {
    "card_id": "1699670576265x928796749151534600",
    "category": "Baseball",
    "category_group": "Sports Cards",
    "description": "C.C. Sabathia 1999 Bowman Chrome Baseball",
    "image": "https://942284f33c575895b4be9de571ca6e40.cdn.bubble.io/d112/f1699670857725x475053799924132860/resized_20231111_024737.jpeg",
    "number": "344",
    "player": "C.C. Sabathia",
    "set": "1999 Bowman Chrome Baseball",
    "set_type": "Bowman Chrome Baseball",
    "variant": "Base"
  },
  "cert_info": {
    "cert": "50000000",
    "description": "1999 Bowman Chrome C.C. Sabathia 344",
    "gemrate_id": "25783324b9710f1366ca4d54f3dd4689c02b6885",
    "grade": "PSA 10",
    "grader": "psa",
    "universal_gemrate_id": "25783324b9710f1366ca4d54f3dd4689c02b6885"
  },
  "prices": [
    {
      "Grade": "PSA 10",
      "card_id": "1699670576265x928796749151534600",
      "closing_date": "2025-10-26T23:59:00.000Z",
      "price": "125.50"
    },
    {
      "Grade": "PSA 10",
      "card_id": "1699670576265x928796749151534600",
      "closing_date": "2025-10-25T23:59:00.000Z",
      "price": "122.00"
    }
  ]
}