NestJs Integration

Getting Started

Create a new NestJs app.

nest new prici-nest

Installing Dependencies

Install Prici's sdk.

npm install @prici/sdk

To use environment variables options, install dotenv as well.

npm install dotenv

Setup

Create a .env file at the root folder, paste these in and update the values.

# JWT Token to be used
# when sending requests
# to Prici service
PRICI_TOKEN=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ0ZW5hbnQiOiJkZWZhdWx0IiwiaWQiOiIxIn0.jSp5c6WCjtJ5E5c2325pWzMsaxpwDJnr6TcPcE2xTKA
#Prici service base URL
PRICI_BASE_URL=http://0.0.0.0:9000

Go to main.ts and at the top of the file add an import for dotenv.

import "dotenv/config"

Using the SDK

Create a new ts file within your folder structure for creating and exporting a new SDK instance (e.g. common/prici.ts) and paste the following code.

import { initialize } from "@prici/sdk";

export const priciSdk = initialize({
    priciUBaseUrl: process.env.PRICI_BASE_URL,
    token: process.env.PRICI_TOKEN
});

Please note that passing the options object is optional when using environment variables.

Open the controller/service file you intend to use with the SDK and import the SDK instance.

import { priciSdk } from "./common/prici";

Now you can use the SDK to check and update users plan limits.

const featureId = process.env.TODOS_FEATURE_ID as string;

@Controller()
export class AppController {
    constructor(private readonly appService: AppService) {
    }

    @Post("todos")
    async createTodo(@Body() body: any) {
        const state = await priciSdk.getFieldState('demo-account', featureId)
    
        if (!state.isAllowed) {
            throw new BadRequestException("limit reached");
        }
        const todo = this.appService.createTodo(body);
        priciSdk.incrementField('demo-account', featureId).catch()

        return todo;
    }
}

Using Guards

Prici currently has one guard.

This guard is called IsAllowedGuard and its job is to validate that a user has not reached its limit quota before your route handler runs and if all is well, it will update the new usage when sending the response back.

To use this guard, first follow all steps in this guide up until importing the SDK instance in the controller file and then add these imports

import { UseGuards } from '@nestjs/common';
import { IsAllowedGuard } from "@prici/sdk/nest"

Now you can use the guard as a route guard

const featureId = process.env.TODOS_FEATURE_ID as string;

@Controller()
export class AppController {
    constructor(private readonly appService: AppService) {
    }

    @Post("todos")
    @UseGuards(new IsAllowedGuard({
        sdk: priciSdk, //required field
        errorMessage: "User is out of quota", //required field
        getAccountId: (_) => "demo-account",
        getFieldId: (_) => featureId
    }))
    createTodo(@Body() body: any) {
        return this.appService.createTodo(body);
    }
}