feat: basic api

client/src/app/services/api.ts

@@ -0,0 +1,17 @@
+import { HttpClient } from '@angular/common/http';
+import { Injectable } from '@angular/core';
+import { Observable } from 'rxjs';
+import { Transaction } from '@shared/interfaces/transaction'
+
+@Injectable({
+  providedIn: 'root',
+})
+export class APIService {
+  private apiUrl = 'http://localhost:3000/api' 
+  
+  constructor(private http: HttpClient){}
+
+  getTransactions(): Observable<Transaction[]>{
+    return this.http.get<Transaction[]>(this.apiUrl + '/transactions');
+  }
+}