Quickstart

What you'll learn

We're going to build a simple leaderboard module from scratch. Users will be able to authenticate, submit leaderboard scores, and retrieve the top scores.

This will teach you how to build a simple leaderboard module from scratch & all related modules concepts including:

Create a module
Setup your database
Write scripts
Write a test

Make sure you've installed the Rivet CLI as described here.

Step 2: Create module

In the same terminal, run:

rivet create module my_leaderboard

Command Line

Might be useful!

See documentation on the module.json config here.

Step 3: Write database schema

Edit your modules/my_leaderboard/db/schema.prisma file to look like this:

datasource db {
    provider = "postgresql"
    url      = env("DATABASE_URL")
}

model Scores {
    id        String   @id @default(uuid()) @db.Uuid
    createdAt DateTime @default(now()) @db.Timestamp
    userId    String   @db.Uuid
    score     Int

    @@index([score])
}

Prisma

Might be useful!

For more information about wwriting database schemas, see Prisma's documentation on data modelling.

Heads up!

Modules are powered by PostgreSQL.

Learn about why we chose PostgreSQL here.

Step 4: Write `submit_score` script

We're going to create a submit_score script that will:

Throttle requests
Validate user token
Insert score
Query score rank

Create script

In the same terminal, run:

rivet create script my_leaderboard submit_score

Command Line

This will create a new file modules/my_leaderboard/scripts/submit_score.ts:

import { ScriptContext } from "../module.gen.ts";

export interface Request {}

export interface Response {}

export async function run(ctx: ScriptContext, req: Request): Promise<Response> {
// TODO: Implement code for my_leaderboard/submit_score
throw new Error("Unimplemented");
}

TypeScript

This command also udpated modules/my_leaderboard/module.json to include the new script:

{
	"scripts": {
		"submit_score": {}
	},
	"errors": {}
}

JSON

Add dependencies & make public

Update the modules/my_leaderboard/module.json file to look like this:

{
	"dependencies": {
		"users": {},
		"rate_limit": {}
	},
	"scripts": {
		"submit_score": null
	},
	"public": true,
	"errors": {}
}

JSON

Update request & response

Open modules/my_leaderboard/scripts/submit_score.ts and update Request and Response to look like this:

export interface Request {
	userToken: string;
	score: number;
}

export interface Response {
	rank: number;
}

TypeScript

Throttle requests

At the top the run function in modules/my_leaderboard/scripts/submit_score.ts file, add code to throttle requests:

export async function run(ctx: ScriptContext, req: Request): Promise<Response> {
	await ctx.modules.rateLimit.throttlePublic({ requests: 1, period: 15 });
	// ...
}

TypeScript

Validate user token

Then authenticate the user:

export async function run(ctx: ScriptContext, req: Request): Promise<Response> {
	// ...
	const validate = await ctx.modules.users.authenticateUser({ userToken: req.userToken });
	///
}

TypeScript

Insert score

Then insert the score in to the database:

export async function run(ctx: ScriptContext, req: Request): Promise<Response> {
	// ...
	await ctx.db.scores.create({
		data: {
			userId: validate.userId,
			score: req.score,
		},
	});
	// ...
}

TypeScript

Query rank

Finally, query the score's rank:

export async function run(ctx: ScriptContext, req: Request): Promise<Response> {
	// ...
	const rank = await ctx.db.scores.count({
		where: {
			score: { gt: req.score },
		},
	});

	return {
		rank: rank + 1,
	};
}

TypeScript

import { ScriptContext } from "../module.gen.ts";

export interface Request {
	userToken: string;
	score: number;
}

export interface Response {
	rank: number;
}

export async function run(
	ctx: ScriptContext,
	req: Request,
): Promise<Response> {
	await ctx.modules.rateLimit.throttlePublic({ requests: 1, period: 15 });
	const validate = await ctx.modules.users.authenticateUser({
		userToken: req.userToken,
	});

	await ctx.db.scores.create({
		data: {
			userId: validate.userId,
			score: req.score,
		},
	});

	const rank = await ctx.db.scores.count({
		where: {
			score: { gt: req.score },
		},
	});

	return {
		rank: rank + 1,
	};
}

TypeScript

Might be useful!

For more information about querying databases, see Prisma's documentation on querying data.

Step 5: Create `get_top_scores` script

Create script

In the same terminal, run:

rivet create script my_leaderboard get_top_scores

Command Line

Make public

Open modules/my_leaderboard/module.json and update the get_top_scores script to be public:

{
	"scripts": {
		"get_top_scores": null
	},
	"public": true
}

JSON

Update request & response

Open modules/my_leaderboard/scripts/get_top_scores.ts and update Request and Response to look like this:

export interface Request {
	count: number;
}

export interface Response {
	scores: Score[];
}

export interface Score {
	userId: string;
	createdAt: string;
	score: number;
}

TypeScript

Throttle requests

At the top the run function in modules/my_leaderboard/scripts/get_top_scores.ts file, add code to throttle the requests:

export async function run(ctx: ScriptContext, req: Request): Promise<Response> {
	await ctx.modules.rateLimit.throttlePublic({});
	// ...
}

TypeScript

Query scores

Then query the top scores:

export async function run(ctx: ScriptContext, req: Request): Promise<Response> {
	// ...
	const rows = await ctx.db.scores.findMany({
		take: req.count,
		orderBy: { score: "desc" },
		select: { userId: true, createdAt: true, score: true },
	});
	// ...
}

TypeScript

Convert rows

Finally, convert the database rows in to Score objects:

export async function run(ctx: ScriptContext, req: Request): Promise<Response> {
	// ...
	const scores = [];
	for (const row of rows) {
		scores.push({
			userId: row.userId,
			createdAt: row.createdAt.toISOString(),
			score: row.score,
		});
	}

	return { scores };
}

TypeScript

import {  ScriptContext } from "../module.gen.ts";

export interface Request {
	count: number;
}

export interface Response {
	scores: Score[];
}

export interface Score {
	userId: string;
	createdAt: string;
	score: number;
}

export async function run(
	ctx: ScriptContext,
	req: Request,
): Promise<Response> {
	await ctx.modules.rateLimit.throttlePublic({});

	const rows = await ctx.db.scores.findMany({
		take: req.count,
		orderBy: { score: "desc" },
		select: { userId: true, createdAt: true, score: true },
	});

	const scores = [];
	for (const row of rows) {
		scores.push({
			userId: row.userId,
			createdAt: row.createdAt.toISOString(),
			score: row.score,
		});
	}

	return {
		scores: scores,
	};
}

TypeScript

Step 6: Start development server

Start development server

In the same terminal, run:

rivet dev

Command Line

Migrate database

You will be prompted to apply your schema changes to the database. Name the migration init (this name doesn't matter):

Migrate Database develop (my_leaderboard) Prisma schema loaded from schema.prisma Datasource "db": PostgreSQL database "my_leaderboard", schema "public" at "host.docker.internal:5432" ? Enter a name for the new migration: › init

Success

You've now written a full module from scratch. You can now generate an SDK to use in your game or publish it to a registry.

Step 7 (optional): Test module

Tests are helpful for validating your module works as expected before running in to the issue down the road. Testing is optional, but strongly encouraged.

Heads up!

All modules provided in the default registry are thoroughly tested.

Create test

rivet create test my_leaderboard e2e

Command Line

Might be useful!

e2e stands for "end to end" test. E2E tests simulate real-world scenarios involving multiple parts of a system. These tend to be comprehensive and catch the most bugs.

Write test

Update modules/my_leaderboard/tests/e2e.ts to look like this:

import { test, TestContext } from "../module.gen.ts";
import { assertEquals } from "https://deno.land/[email protected]/assert/mod.ts";
import { faker } from "https://deno.land/x/[email protected]/mod.ts";

test("e2e", async (ctx: TestContext) => {
	// Create user & token to authenticate with
	const { user } = await ctx.modules.users.createUser({});
	const { token } = await ctx.modules.users.createUserToken({
		userId: user.id,
	});

	// Create some scores
	const scores = [];
	for (let i = 0; i < 10; i++) {
		const score = faker.random.number({ min: 0, max: 100 });
		await ctx.modules.myLeaderboard.submitScore({
			userToken: token.token,
			score: score,
		});
		scores.push(score);
	}

	// Get top scores
	scores.sort((a, b) => b - a);
	const topScores = await ctx.modules.myLeaderboard.getTopScores({ count: 5 });
	assertEquals(topScores.scores.length, 5);
	for (let i = 0; i < 5; i++) {
		assertEquals(topScores.scores[i].score, scores[i]);
	}
});

TypeScript

Run test

In the same terminal, run:

rivet module test

Command Line

You should see this output once complete:

...test logs... ----- output end ----- e2e ... ok (269ms) ok | 1 passed | 0 failed (280ms)

Quickstart

What you'll learn

Prerequisites

Step 1: Create project

Step 2: Create module

Might be useful!

Step 3: Write database schema

Might be useful!

Heads up!

Step 4: Write `submit_score` script

Create script

Add dependencies & make public

Update request & response

Throttle requests

Validate user token

Insert score

Query rank

Might be useful!

Step 5: Create `get_top_scores` script

Create script

Make public

Update request & response

Throttle requests

Query scores

Convert rows

Step 6: Start development server

Start development server

Migrate database

Success

Step 7 (optional): Test module

Heads up!

Create test

Might be useful!

Write test

Run test