lending-apy-fetcher-ts/src/types/index.ts

TypeScript library for fetching APYs from DeFi lending protocols

// Core data types for APY fetching
export interface ApyData {
  token_symbol: string;
  apy: number;
  protocol_name: string;
  network: string;
  additional_info?: Record<string, any>;
}

// Protocol interface that all implementations must follow
export interface Protocol {
  name: string;
  network: string;
  fetchApys(): Promise<ApyData[]>;
}

// Custom error types for different failure modes
export class ApyFetcherError extends Error {
  constructor(
    message: string,
    public readonly protocol?: string,
    public readonly cause?: Error
  ) {
    super(message);
    this.name = 'ApyFetcherError';
  }
}

export class NetworkError extends ApyFetcherError {
  constructor(message: string, protocol?: string, cause?: Error) {
    super(message, protocol, cause);
    this.name = 'NetworkError';
  }
}

export class ValidationError extends ApyFetcherError {
  constructor(message: string, protocol?: string, cause?: Error) {
    super(message, protocol, cause);
    this.name = 'ValidationError';
  }
}

export class AuthenticationError extends ApyFetcherError {
  constructor(message: string, protocol?: string, cause?: Error) {
    super(message, protocol, cause);
    this.name = 'AuthenticationError';
  }
}

// Utility types
export interface TokenMapping {
  [address: string]: string;
}

export interface NetworkTokenMappings {
  [network: string]: TokenMapping;
}

export interface ApyResult {
  success: boolean;
  data?: ApyData[];
  error?: ApyFetcherError;
  protocol: string;
}

export interface GroupedApys {
  [tokenSymbol: string]: ApyData[];
}

export interface BestApyResult {
  token_symbol: string;
  apy: number;
  network: string;
}