Hello, This is an exemple for Odoo 11. Hope it help you

1. You need to fix the database in your odoo conf file

[options]

; This is the password that allows database operations:

; admin_passwd = admin

db_name = your_database_name

dbfilter = your_database_name

list_db = False

2. Then you can try this sample code

# -*- coding: utf-8 -*-
import json
from odoo import http
from odoo.http import request, Response

class MyApiClass(http.Controller):

	@http.route("/my/get/api/path", auth='none', type='http', method=['GET'], cors='*')
	def get_api_method(self, *kw):
		partners = request['res.partners'].sudo().search_read([])

		headers = {'Content-Type': 'application/json'}
		body = { 'results': { 'code': 200, 'message': partners } }

		return Response(json.dumps(body), headers=headers)


	@http.route("/my/post/api/path", auth='none', type='http', method=['POST'], csrf=False, cors='*')
	def post_api_method(self, email, *kw):
		partners = request['res.partners'].sudo().search_read([('email','=',email)])

		headers = {'Content-Type': 'application/json'}
		body = { 'results': { 'code': 200, 'message': partners } }

		return Response(json.dumps(body), headers=headers)