Show HN: Kapso – WhatsApp for developers
48 points - 12/23/2025
Hey HN, I'm Andres. I've been building Kapso as a solo founder, and just crossed 4,000 developers, all organic.
WhatsApp has 3B+ users and 98% open rates. You'd expect developers to be building tons of stuff on it, especially when the US is the fastest-growing market in WhatsApp usage.
But it’s not happening… And I'd bet it's because the DX is painful.
Every team needs to build the same features again and again. Meta fires webhooks for everything. There's valuable data in there for debugging, but no way to make sense of it without building your own tooling.
That’s why I built Kapso. What you get:
- Working WhatsApp API + inbox in 2 minutes, not days
- Full observability: every webhook parsed, every message tracked, actual debugging tools
- Multi-tenant platform: generate a setup link, customer connects their Meta account, done
- Workflow builder for deterministic automations and AI Agents
- WhatsApp Flows: build mini apps inside WhatsApp using AI + serverless functions
- Docs that work for humans and LLMs
We're up to 95% cheaper than Twilio, with a generous free tier (2,000 messages per month).
We also open source several tools: a TypeScript client for the WhatsApp Cloud API, a reference WhatsApp Inbox implementation, and a voice AI agent for WhatsApp.
GitHub: https://github.com/gokapso/
Happy to answer questions!
https://kapso.ai/
Congrats, this is a strong primitive for modern SaaS, especially in LATAM.
Building software today increasingly means integrating dozens of external services rather than building systems end to end. Email, auth, analytics, billing, AI tooling, and observability each come with their own accounts, configs, SDKs, and API keys.
This composability is powerful, but increasingly inefficient.
It makes me wonder when we’ll see a platform that bundles these services with unified accounts, billing, auth, and configuration by default, instead of having to configure and manage each one independently.
Thanks! Agreed on the composability pain. That's part of why we bundle inbox, observability, workflows, etc, together.
Let's goo! That's awesome! Finally a decent API with a generous free tier. Thank you for that.
Quick question, are you using the official Meta API on your side?
thanks! yes, we use the official Meta API
This is really really cool, and thank you for the free tier as well.
Always been a bit put off using WhatsApp as I've seen the pain some devs have had to go through to integrate it, this looks smooth.
Excited to have a play around with this.
thanks! and yeah, the integration pain is exactly why I built this.
let me know what you think once you try it!
Documentation and sandbox is good, however is the facebook account a hard requirement to getting a number and templates setup? I've paid the $6 for a number however I don't have (or want) a facebook account, so seems I'm a bit stuck.
yeah unfortunately you need a Facebook account
Ahh gutted. I should have realised this from the wording for sandbox mode:
> Get a Kapso sandbox number to test your integrations. Start building without a phone number or Meta account.
It might be good just to state that you need a Meta account for a number.
Wow. this is beautiful. Congrats on the launch!
I've been using Kapso for the last couple of months, and it’s flawless.
Love it. Any plans for other integrations like instagram/linkedin?
Thanks! For now we're focused on going deeper on WhatsApp. There's still a lot to build. But other channels aren't off the table eventually.
Do you have support for whatsapp group management?
Hey aamatte, why do you charge 95% less than Twilio?
Twilio priced WhatsApp messages like SMS: $0.005 per message.
That made sense for SMS where you send one message and you're done.
But WhatsApp conversations don't work that way. People send bursts of short messages instead of one long one.
A typical conversation can easily hit 30-50 messages. Building AI agents with that pricing gets expensive fast.
At Twilio's rates, 100k messages would cost you $500.
Our Pro plan is $25/month and includes 100k messages.
Congrats on the amazing product!
Why are you using the .ai TLD? This doesn't look like it has anything to do with AI.
at the beginning Kapso was more focused on ai agents :)
Interesting. I recommend picking up a new domain name, they're cheap and the AI thing might confuse people or make them skeptical (it has for at least one person)