MCP Helius

Instructions

Implementation Reference

• src/handlers/helius.ts:508-517 (handler)

  The core handler function for 'helius_get_fee_for_message'. Deserializes base64-encoded message to VersionedMessage, computes fee using Helius RPC connection.getFeeForMessage, and formats response.

  export const getFeeForMessageHandler = async (input: GetFeeForMessageInput): Promise<ToolResultSchema> => {
    try {
      const messageBytes = Buffer.from(input.message, 'base64');
      const versionedMessage = VersionedMessage.deserialize(messageBytes);
      const fee = await (helius as any as Helius).connection.getFeeForMessage(versionedMessage, input.commitment);
      return createSuccessResponse(`Fee for message: ${JSON.stringify(fee, null, 2)}`);
    } catch (error) {
      return createErrorResponse(`Error getting fee for message: ${error instanceof Error ? error.message : String(error)}`);
    }
  }

• src/tools.ts:504-515 (schema)

  Input schema definition for the tool, specifying base64 message and optional commitment level.

  {
    name: 'helius_get_fee_for_message',
    description: 'Get the fee for a serialized message',
    inputSchema: {
      type: 'object',
      properties: {
        message: { type: 'string', description: 'Base64 encoded message string' },
        commitment: { type: 'string', enum: ['confirmed', 'finalized', 'processed'] }
      },
      required: ['message']
    }
  },

• src/tools.ts:589-589 (registration)

  Maps the tool name 'helius_get_fee_for_message' to its handler function in the handlers dictionary.

  "helius_get_fee_for_message": getFeeForMessageHandler,