diff --git a/erpnext-mcp/src/types.ts b/erpnext-mcp/src/types.ts
new file mode 100644
index 0000000..5efefff
--- /dev/null
+++ b/erpnext-mcp/src/types.ts
@@ -0,0 +1,52 @@
+export interface ERPNextConfig {
+  baseUrl: string;
+  apiKey: string;
+  apiSecret: string;
+}
+
+export interface ERPNextListParams {
+  fields?: string[];
+  filters?: Array<[string, string, string, string | number | boolean]>;
+  or_filters?: Array<[string, string, string, string | number | boolean]>;
+  order_by?: string;
+  limit_start?: number;
+  limit_page_length?: number;
+  group_by?: string;
+}
+
+export interface ERPNextResponse<T = unknown> {
+  data: T;
+  message?: string;
+}
+
+export interface ERPNextListResponse<T = unknown> {
+  data: T[];
+}
+
+export interface PaginatedResult<T = unknown> {
+  total: number;
+  count: number;
+  offset: number;
+  items: T[];
+  has_more: boolean;
+  next_offset?: number;
+}
+
+export interface DocInfo {
+  name: string;
+  doctype: string;
+  [key: string]: unknown;
+}
+
+export interface ToolCategory {
+  name: string;
+  description: string;
+  tools: ToolDefinition[];
+}
+
+export interface ToolDefinition {
+  name: string;
+  title: string;
+  description: string;
+  register: (server: unknown, client: unknown) => void;
+}