Add API rate limit (#23)

apps/web/src/env.js

@@ -40,6 +40,10 @@ export const env = createEnv({
     GOOGLE_CLIENT_SECRET: z.string(),
     SES_QUEUE_LIMIT: z.string().transform((str) => parseInt(str, 10)),
     AWS_DEFAULT_REGION: z.string().default("us-east-1"),
+    API_RATE_LIMIT: z
+      .string()
+      .transform((str) => parseInt(str, 10))
+      .default(2),
   },
 
   /**
@@ -72,6 +76,7 @@ export const env = createEnv({
     GOOGLE_CLIENT_SECRET: process.env.GOOGLE_CLIENT_SECRET,
     SES_QUEUE_LIMIT: process.env.SES_QUEUE_LIMIT,
     AWS_DEFAULT_REGION: process.env.AWS_DEFAULT_REGION,
+    API_RATE_LIMIT: process.env.API_RATE_LIMIT,
   },
   /**
    * Run `build` or `dev` with `SKIP_ENV_VALIDATION` to skip env validation. This is especially

apps/web/src/server/public-api/auth.ts

@@ -1,20 +1,30 @@
+import TTLCache from "@isaacs/ttlcache";
 import { Context } from "hono";
 import { hashToken } from "../auth";
 import { db } from "../db";
 import { UnsendApiError } from "./api-error";
+import { env } from "~/env";
+
+const rateLimitCache = new TTLCache({
+  ttl: 1000, // 1 second
+  max: env.API_RATE_LIMIT,
+});
 
 /**
  * Gets the team from the token. Also will check if the token is valid.
  */
 export const getTeamFromToken = async (c: Context) => {
   const authHeader = c.req.header("Authorization");
+
   if (!authHeader) {
     throw new UnsendApiError({
       code: "UNAUTHORIZED",
       message: "No Authorization header provided",
     });
   }
+
   const token = authHeader.split(" ")[1];
+
   if (!token) {
     throw new UnsendApiError({
       code: "UNAUTHORIZED",
@@ -22,6 +32,8 @@ export const getTeamFromToken = async (c: Context) => {
     });
   }
 
+  checkRateLimit(token);
+
   const hashedToken = hashToken(token);
 
   const team = await db.team.findFirst({
@@ -55,3 +67,18 @@ export const getTeamFromToken = async (c: Context) => {
 
   return team;
 };
+
+const checkRateLimit = (token: string) => {
+  let rateLimit = rateLimitCache.get<number>(token);
+
+  rateLimit = rateLimit ?? 0;
+
+  if (rateLimit >= 2) {
+    throw new UnsendApiError({
+      code: "RATE_LIMITED",
+      message: `Rate limit exceeded, ${env.API_RATE_LIMIT} requests per second`,
+    });
+  }
+
+  rateLimitCache.set(token, rateLimit + 1);
+};