diff --git a/lib/CrudHandler.ts b/lib/CrudHandler.ts
index 70cb09c..6b3ba33 100644
--- a/lib/CrudHandler.ts
+++ b/lib/CrudHandler.ts
@@ -1,3 +1,5 @@
+import { Request, Response } from 'express';
+
 export interface CrudHandler {
   public create(req: Request, res: Response): Promise<void>;
   public read(req: Request, res: Response): Promise<void>;
diff --git a/lib/KnexCrudHandler.ts b/lib/KnexCrudHandler.ts
index 89585fb..13f1761 100644
--- a/lib/KnexCrudHandler.ts
+++ b/lib/KnexCrudHandler.ts
@@ -100,12 +100,11 @@ export class KnexCrudHandler extends HttpHandler implements CrudHandler {
     }
 
     const json = await this.knex (this.table)
-      .select ([
+      .where ({ id: req.headers.id })
+      .select (
         'id',
         ...this.columns
-      ])
-      .where ({ id: req.headers.id });
-
+      );
     res.status (json.length > 0 ? http.status_ok : http.status_not_found)
       .json (json[0]);
   }
@@ -133,7 +132,7 @@ export class KnexCrudHandler extends HttpHandler implements CrudHandler {
       .update (db_data);
 
     res.status (http.status_ok)
-      .end (inserted[0]);
+      .end ();
   }
 
   public async delete (req: Request, res: Response): Promise<void> {
diff --git a/lib/KnexCrudOptions.ts b/lib/KnexCrudOptions.ts
index 905905a..2f02a88 100644
--- a/lib/KnexCrudOptions.ts
+++ b/lib/KnexCrudOptions.ts
@@ -1,8 +1,8 @@
 import { Request, Response } from 'express';
 
 type Authorization = {
-  (req: Request, res: Response, next: Function);
   (req: Request, res: Response): Promise<boolean>;
+  (req: Request, res: Response, next: Function): unknown;
 }
 
 type AuthRunner = {
@@ -23,66 +23,66 @@ export class KnexCrudOptions {
   ): AuthRunner {
     if (typeof auth === 'undefined')
       return (): Promise<boolean> => new Promise ((r) => r (true));
-    return (): Promise<boolean> => new Promise ((resolve) => {
+    return (req, res): Promise<boolean> => new Promise ((resolve) => {
       const result = auth (req, res, resolve);
       if (typeof result !== 'undefined')
-        resolve (result);
+        resolve (result as boolean);
     });
   }
 
-  public set general_authorization (value: Authorization): void{
+  public set general_authorization (value: Authorization) {
     this._general_authorization = value;
   }
 
-  public get create_authorization (): AuthRunner {
+  public get create_authorization (): Authorization {
     const general = this.get_auth_runner (this._general_authorization);
     const specific = this.get_auth_runner (this._create_authorization);
-    return async (req, res): Promise<boolean> => {
-      const res = (await general (req, res)) && (await specific (req, res));
-      return res;
+    return async (req: Request, res: Response): Promise<boolean> => {
+      const result = (await general (req, res)) && (await specific (req, res));
+      return result;
     };
   }
 
-  public set create_authorization (value: Authorization): void{
+  public set create_authorization (value: Authorization) {
     this._create_authorization = value;
   }
 
-  public get read_authorization (): AuthRunner {
+  public get read_authorization (): Authorization {
     const general = this.get_auth_runner (this._general_authorization);
     const specific = this.get_auth_runner (this._read_authorization);
-    return async (req, res): Promise<boolean> => {
-      const res = (await general (req, res)) && (await specific (req, res));
-      return res;
+    return async (req: Request, res: Response): Promise<boolean> => {
+      const result = (await general (req, res)) && (await specific (req, res));
+      return result;
     };
   }
 
-  public set read_authorization (value: Authorization): void{
+  public set read_authorization (value: Authorization) {
     this._read_authorization = value;
   }
 
-  public get update_authorization (): AuthRunner {
+  public get update_authorization (): Authorization {
     const general = this.get_auth_runner (this._general_authorization);
     const specific = this.get_auth_runner (this._update_authorization);
-    return async (req, res): Promise<boolean> => {
-      const res = (await general (req, res)) && (await specific (req, res));
-      return res;
+    return async (req: Request, res: Response): Promise<boolean> => {
+      const result = (await general (req, res)) && (await specific (req, res));
+      return result;
     };
   }
 
-  public set update_authorization (value: Authorization): void{
+  public set update_authorization (value: Authorization) {
     this._update_authorization = value;
   }
 
-  public get delete_authorization (): AuthRunner {
+  public get delete_authorization (): Authorization {
     const general = this.get_auth_runner (this._general_authorization);
     const specific = this.get_auth_runner (this._delete_authorization);
-    return async (req, res): Promise<boolean> => {
-      const res = (await general (req, res)) && (await specific (req, res));
-      return res;
+    return async (req: Request, res: Response): Promise<boolean> => {
+      const result = (await general (req, res)) && (await specific (req, res));
+      return result;
     };
   }
 
-  public set delete_authorization (value: Authorization): void{
+  public set delete_authorization (value: Authorization) {
     this._delete_authorization = value;
   }
 }
diff --git a/lib/KnexInterface.ts b/lib/KnexInterface.ts
index 8b072d8..8ad894e 100644
--- a/lib/KnexInterface.ts
+++ b/lib/KnexInterface.ts
@@ -1,10 +1,10 @@
 /* eslint-disable @typescript-eslint/naming-convention */
 
 interface KnexQuery {
-  insert(data: object): Promise;
-  update(data: object): Promise;
-  select(...columns: Array<string>): Promise;
-  delete(): Promise;
+  insert(data: object): Promise<Array<unknown>>;
+  update(data: object): Promise<unknown>;
+  select(...columns: Array<string>): Promise<Array<object>>;
+  delete(): Promise<unknown>;
   where(filter: object): KnexQuery;
   whereNot(filter: object): KnexQuery;
   whereIn(filter: object): KnexQuery;
diff --git a/lib/index.ts b/lib/index.ts
new file mode 100644
index 0000000..63ab5bb
--- /dev/null
+++ b/lib/index.ts
@@ -0,0 +1,3 @@
+export { HttpHandler } from './HttpHandler';
+export { CrudHandler } from './CrudHandler';
+export { KnexCrudHandler } from './KnexCrudHandler';