How I built a chat app using Streams API, Next.JS, Redis and Vercel

Last week I added a chat feature to Sanity. In this article, I'll guide through how I built it using Streams API, Next.js, Redis and Vercel.

Before we start, a quick disclaimer: there are much better ways to build a chat application, for example by using WebSockets. Vercel unfortunately doesn't support WebSockets and I didn't want to spin a dedicated server, which is why I used Streams API. Using Streams API the way I use it here is most likely not the best use of resources but it works and is a good enough solution for my small scale use. If you're on the same boat, keep reading.

If the chat takes off, I'll have to move it to a dedicated Socket.io server, a serverless WebSocket on AWS, or something similar to reduce costs.

Storing messages in Redis

I use the KV (Redis) database from Vercel to store the last 100 messages. Here is the code used to send and read messages.

import { MAX_CHAT_MESSAGE_LENGTH } from "@/utils";

const MAX_MESSAGES = 100;

export const addChatMessage = async ({

How I implemented slugs on Sanity - a TypeScript code sample

The lack of human-readable slugs on Sanity had bothered me for a while and I finally got around to fixing them last Sunday. The old, slugless URL structure probably wasn't doing me any favors in terms of SEO and user experience. I'm hoping the new format can give Sanity a much needed SEO boost. Plus, I can finally tell which post is which in Google Search Console and Vercel Analytics.

The Result

Before

https://www.sanity.media/p/64c375049f5d6b05859f10c6

After

https://www.sanity.media/p/64c375049f5d6b05859f10c6-delicious-post-workout-milkshake-recipe

Isn't this much clearer?

The Code

When writing the code I had the following goals in mind:

Is there a secure way to use Redis with Vercel?

I spent a couple of hours yesterday trying to find a way to use Redis with Sanity, which currently runs on Vercel. According to Redis docs on security, it is not a good idea to expose a Redis instance directly to the internet:

Redis is designed to be accessed by trusted clients inside trusted environments. This means that usually it is not a good idea to expose the Redis instance directly to the internet or, in general, to an environment where untrusted clients can directly access the Redis TCP port or UNIX socket.

I wanted to use Digital Ocean's trusted sources to restrict the incoming connections to those coming from my Vercel server but looks like that won't be possible because of Vercel's use of dynamic IP addresses. According to Vercel docs:

To ensure your Vercel deployment is able to access the external resource, you should allow connections from all IP addresses. Typically this can be achieved by entering an IP address of (0.0.0.0).

While allowing connections from all IP addresses may be a concern, relying on IP allowlisting for security is generally ineffective and can lead to poor security practices.

To properly secure your database, we recommend using a randomly generated password, stored as an environment variable, at least 32 characters in length, and to rotate this password on a regular basi...

some bugs with sanity

hey @tomasz, I'm noticing a few bugs with sanity. I noticed the upvotes and downvotes are not updating properly. Another issue I noticed is that when I am on my profile it is refreshing over and over again for about 10-15 seconds, I'm not sure if there is a failure to fetch problem....or something like that? might be worth looking into

<3 Radishes

How I fixed @aws-crypto build error

I've been getting the following error when building my Next.js app:

Failed to compile.

./node_modules/.pnpm/@aws-crypto+sha256-js@5.2.0/node_modules/@aws-crypto/sha256-js/build/module/index.js + 12 modules Cannot get final name for export 'fromUtf8' of ./node_modules/.pnpm/@smithy+util-utf8@2.0.2/node_modules/@smithy/util-utf8/dist-es/index.js

I narrowed the source down to the following piece of code:

import { createServerRunner } from "@aws-amplify/adapter-nextjs";
import { AWS_AMPLIFY_CONFIG } from "./utils";
import { cookies } from "next/headers";
import { getCurrentUser } from "aws-amplify/auth/server";

export const { runWithAmplifyServerContext } = createServerRunner({
  config: AWS_AMPLIFY_CONFIG,
});

How to implement AI vector search and related posts with pgvector

At the end of this tutorial, you should be able to set up your own vector search with text embeddings in a Next.js app. This is a tutorial that mostly consists of coding samples taken directly from the Sanity codebase.

You can see the results right here on Sanity. The related posts section underneath each post is generated with pgvector. So is the search.

The stack I used:

• Open AI's text-embedding-ada-002 model
• Next.js
• Prisma
• PostgreSQL

Start by setting up the Prisma client:

This step is needed to get Prisma to cooperate with Next.js.

// Setting up prisma

Sanity SEO Performance After 9 Months

Still only get 0-5 clicks a day but things are heading in the right direction.

Impressions

Clicks

Crawl Stats

Any tips on how to coerce Googlebot to crawl more?

How to use AWS Amplify Authentication with Next.js Server Actions

No next-auth required:

// amplifyServerUtils.ts

import { createServerRunner } from '@aws-amplify/adapter-nextjs';
import config from '@/amplifyconfiguration.json';

export const { runWithAmplifyServerContext } = createServerRunner({
  config
});

// actions.ts

"use server";
import { cookies } from "next/headers";

Fixing AWS Timestream query

My 'ago' function had been failing with "The query syntax is invalid" error on the following clause:

time BETWEEN ago(24h5m) AND ago(24h) AND

I fixed it by changing converting the hours to minutes:

time BETWEEN ago(1445m) AND ago(1440m) AND

A user acquisition conundrum

One of the fastest ways I can attract the first users to Sanity and start getting feedback is by posting about it and engaging on Facebook and Twitter. The thing is, I find them too addictive and full of dark patterns, which is why started Sanity in the first place. I always tell myself I’ll only use them for a specific purpose, or for 15 minutes a day, or only occasionally, and then I gradually get sucked into using them all the time. I start out by visiting once every few days, I check for new posts from a few people I follow, read some AI news, visit groups etc. With time, I find myself using them more and more until several weeks later, I check them throughout the day. This is more of a problem for me with Twitter but, to a lesser extent, also applies to Facebook.

So the question is - how to I get the word out about Sanity without using the addictive social media networks it’s meant to be the alternative to?

I'm focusing on writing content and optimizing SEO for now but it's a slow process. Any tips?