Scryfall MCP Server

import { ScryfallClient } from '../services/scryfall-client.js'; import { validateCardIdentifier } from '../utils/validators.js'; import { formatCard } from '../utils/formatters.js'; import { ScryfallAPIError, ValidationError } from '../types/mcp-types.js'; /** * MCP Prompt for deck building around a specific card */ export class BuildDeckPrompt { readonly name = 'build_deck'; readonly description = 'Generate a deck building guide centered around a specific Magic: The Gathering card, including strategy, supporting cards, manabase, and sideboard suggestions'; readonly arguments = [ { name: 'card_identifier', description: 'Card name, set code+collector number, or Scryfall ID to build around', required: true }, { name: 'format', description: 'Magic format for the deck (standard, modern, legacy, vintage, commander, pioneer, brawl, standardbrawl)', required: true }, { name: 'budget', description: 'Budget constraint (budget, mid-range, high-end, no-limit)', required: false }, { name: 'playstyle', description: 'Preferred playstyle (aggro, midrange, control, combo, ramp)', required: false }, { name: 'competitive_level', description: 'Target competitive level (casual, fnm, competitive, tournament)', required: false } ]; constructor(private readonly scryfallClient: ScryfallClient) {} async generatePrompt(args: Record<string, string>): Promise<string> { try { const cardIdentifier = args.card_identifier; const format = args.format; const budget = args.budget || 'mid-range'; const playstyle = args.playstyle || 'flexible'; const competitiveLevel = args.competitive_level || 'fnm'; if (!cardIdentifier) { throw new ValidationError('card_identifier is required'); } if (!format) { throw new ValidationError('format is required'); } // Validate and fetch card validateCardIdentifier(cardIdentifier); const card = await this.scryfallClient.getCard({ identifier: cardIdentifier }); const formattedCard = formatCard(card); // Check format legality const formatLegality = formattedCard.legalities[format.toLowerCase()]; if (formatLegality !== 'legal' && formatLegality !== 'restricted') { throw new ValidationError(`Card "${formattedCard.name}" is not legal in ${format} format (status: ${formatLegality})`); } // Generate deck building prompt const prompt = `# Deck Building Guide: ${formattedCard.name} in ${format.toUpperCase()} Build a competitive ${format} deck centered around the following card: ## Focus Card **Name:** ${formattedCard.name} **Mana Cost:** ${formattedCard.mana_cost || 'N/A'} **Type:** ${formattedCard.type_line} **Oracle Text:** ${formattedCard.oracle_text || 'No text'} ${formattedCard.power && formattedCard.toughness ? `**Power/Toughness:** ${formattedCard.power}/${formattedCard.toughness}` : ''} **Rarity:** ${formattedCard.rarity} **Current Price:** ${formattedCard.prices.usd ? `$${formattedCard.prices.usd}` : 'Not available'} ## Deck Building Parameters - **Format:** ${format.toUpperCase()} - **Budget:** ${budget} - **Playstyle:** ${playstyle} - **Competitive Level:** ${competitiveLevel} - **Format Legality:** ${formatLegality} ## Deck Building Framework Please create a comprehensive deck building guide covering: ### 1. Core Strategy Identification - Primary win condition and game plan - Role of the focus card in the strategy - Backup win conditions - Key synergies to exploit ### 2. Supporting Card Recommendations - **Core Synergy Cards:** Cards that directly synergize with ${formattedCard.name} - **Enablers:** Cards that help cast or activate the focus card - **Protection:** Cards that protect the focus card or strategy - **Tutors/Card Selection:** Ways to find the focus card consistently ### 3. Deck Structure and Curve - Recommended mana curve distribution - Number of copies of the focus card (and reasoning) - Card type distribution (creatures, spells, etc.) - Key ratios and deck building principles ### 4. Manabase Construction - Color requirements and mana base needs - Recommended land count - Specific land recommendations - Mana curve considerations ### 5. Complete Decklist Suggestion Provide a sample ${['commander', 'brawl'].includes(format) ? '100' : format === 'standardbrawl' ? '60' : '60'}-card decklist including: - Mainboard (${['commander', 'brawl'].includes(format) ? '99 cards + commander' : format === 'standardbrawl' ? '59 cards + commander' : '60 cards'}) ${!['commander', 'brawl', 'standardbrawl'].includes(format) ? '- Sideboard (15 cards)' : ''} - Specific card quantities and reasoning ### 6. Sideboard Strategy ${['commander', 'brawl', 'standardbrawl'].includes(format) ? '(N/A for Singleton Formats)' : ''} ${!['commander', 'brawl', 'standardbrawl'].includes(format) ? ` - Key matchups to sideboard against - Sideboard card recommendations - Sideboarding guide for common matchups ` : ''} ### 7. Budget Considerations - Total estimated deck cost ${budget === 'budget' ? '- Budget alternatives for expensive cards' : ''} ${budget === 'high-end' || budget === 'no-limit' ? '- Premium upgrades and optimizations' : ''} - Upgrade path recommendations ### 8. Gameplay Guide - Mulligan decisions - Early game priorities - Key decision points - Common play patterns ### 9. Matchup Analysis - Favorable matchups and why - Difficult matchups and how to improve them - Meta positioning in current ${format} ### 10. Alternative Builds - Different approaches to building around this card - Archetype variations - Hybrid strategies ## Additional Requirements - All suggested cards must be legal in ${format} - Consider current meta game and popular decks - Provide specific card names, not just categories - Include reasoning for each major deck building decision - Consider both best-case and realistic scenarios ${competitiveLevel === 'tournament' ? ` ## Tournament Considerations - Current tier placement expectations - Tournament-specific tech choices - Meta game adaptation strategies ` : ''} ${format === 'commander' ? ` ## Commander-Specific Considerations - Political implications and threat assessment - Multiplayer dynamics - Casual vs competitive builds - Social contract considerations ` : ''} ${['brawl', 'standardbrawl'].includes(format) ? ` ## Brawl-Specific Considerations - Arena meta and digital considerations - Singleton deck construction constraints - Commander color identity restrictions - ${format === 'brawl' ? 'Historic card pool (100 cards)' : 'Standard card pool (60 cards)'} - Arena-only card availability requirement - Best-of-one gameplay optimization ` : ''} Please structure the guide with clear sections and provide actionable advice for deck builders at the ${competitiveLevel} level.`; return prompt; } catch (error) { if (error instanceof ValidationError) { throw new Error(`Validation error: ${error.message}`); } if (error instanceof ScryfallAPIError) { if (error.status === 404) { throw new Error(`Card not found: "${args.card_identifier}". Please check the card name or identifier.`); } throw new Error(`Scryfall API error: ${error.message}`); } throw new Error(`Failed to generate deck building prompt: ${error instanceof Error ? error.message : 'Unknown error'}`); } } /** * Gets example usage for this prompt */ getExamples(): Array<{ description: string; arguments: Record<string, string> }> { return [ { description: 'Build a budget Modern deck around Lightning Bolt', arguments: { card_identifier: 'Lightning Bolt', format: 'modern', budget: 'budget', playstyle: 'aggro', competitive_level: 'fnm' } }, { description: 'Tournament-level Standard deck around a specific card', arguments: { card_identifier: 'Teferi, Hero of Dominaria', format: 'standard', budget: 'high-end', playstyle: 'control', competitive_level: 'tournament' } }, { description: 'Commander deck building guide', arguments: { card_identifier: 'Atraxa, Praetors\' Voice', format: 'commander', budget: 'mid-range', playstyle: 'midrange', competitive_level: 'casual' } } ]; } }