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The MTG Deck Builder API provides endpoints for calculating card draw probabilities and searching the Magic: The Gathering card database.

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Base URL

All API requests should be made to: 
http://localhost:4000/api

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Available endpoints

The API provides the following endpoints:

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Probability calculation

  • POST /api/alg - Calculate the probability of being able to play a specific card given a deck composition and number of draws
  • GET /api/cards/allcards - Retrieve all card names and IDs
  • GET /api/cards/filteredcards/:value - Search for cards by name (returns first 10 matches)

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Request format

All POST requests should include a Content-Type: application/json header and a JSON request body. 
curl -X POST http://localhost:4000/api/alg \
  -H "Content-Type: application/json" \
  -d '{"draws": 10, "card": {...}, "deck": [...]}'

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Response format

All responses are returned in JSON format. Successful requests return a 200 status code. 
0.847
For the probability endpoint, the response is a number between 0 and 1 representing the probability, or an empty string if the calculation cannot be performed.

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Authentication

The API does not require authentication. All endpoints are publicly accessible.

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Error handling

Errors are returned with appropriate HTTP status codes:
  • 400 Bad Request - Invalid request parameters
  • 404 Not Found - Endpoint not found
  • 500 Internal Server Error - Server error during processing
Error responses include a message describing the error: 
"Error message describing what went wrong"

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Rate limiting

There are currently no rate limits on API requests.

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Card object structure

Many endpoints work with card objects. A typical card object includes: 
{
  "name": "Lightning Bolt",
  "manaCost": "{R}",
  "type": "Instant",
  "types": ["Instant"],
  "text": "Lightning Bolt deals 3 damage to any target.",
  "ProducibleManaColors": "false",
  "fetchOptions": "",
  "multiverseid": 397722,
  "set": "M15",
  "uniqueName": "lightningbolt"
}
For land cards, the ProducibleManaColors field contains comma-separated color codes (e.g., "R,G" for a land that produces red or green mana).

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Next steps

Probability endpoint

Calculate draw probabilities

Algorithm explanation

Understand the math

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