MCP Crypto Wallet EVM

Instructions

Implementation Reference

• src/handlers/wallet.ts:81-98 (handler)

  The main handler function that generates a mnemonic phrase of the specified length using the @scure/bip39 library. It dynamically imports the wordlist based on locale and calculates entropy bits from the word count.

  export const createMnemonicPhraseHandler = async (input: createMnemonicPhraseHandlerInput): Promise<ToolResultSchema> => {
    try {
      const { wordlist } = await import(`@scure/bip39/wordlists/${input.locale || 'english'}`);
      if (!wordlist) {
        return createErrorResponse("Invalid locale");
      }
      // Convert length to entropy bits (12 words = 128 bits, 15 words = 160 bits, etc)
      const entropyBits = ((input.length ?? 12) / 3) * 32;
      const mnemonic = generateMnemonic(wordlist, entropyBits);
  
      return createSuccessResponse(
      `Mnemonic phrase created successfully:
        Mnemonic: "${mnemonic}"
      `);
    } catch (error) {
      return createErrorResponse(`Failed to create mnemonic phrase: ${(error as Error).message}`);
    }
  };

• src/tools.ts:76-87 (schema)

  The tool schema definition including name, description, and input schema specifying the length (12-24 words) and optional locale.

  {
    name: "wallet_create_mnemonic_phrase",
    description: "Create a mnemonic phrase",
    inputSchema: {
      type: "object",
      properties: {
        length: { type: "number", description: "The length of the mnemonic phrase", enum: [12, 15, 18, 21, 24] },
        locale: { type: "string", description: "Optional locale for the wordlist" }
      },
      required: ["length"]
    }
  },

• src/tools.ts:607-607 (registration)

  Registration of the handler function in the tools handlers dictionary.

  "wallet_create_mnemonic_phrase": createMnemonicPhraseHandler

• src/handlers/wallet.types.ts:6-9 (schema)

  TypeScript type definition for the handler input, matching the tool schema.

  export type createMnemonicPhraseHandlerInput = {
    locale?: string;
    length?: 12 | 15 | 18 | 21 | 24;
  };