Building a "Wevo" - Modeling a Real world promise.

h1d3mun3 — Sun, 29 Mar 2026 08:34:42 +0000

Hi guys :p 👯‍♂

Welcome to Wevo series.

As I introduced in my previous post, I built Wevo.
https://dev.to/h1d3mun3/introducing-wevo-building-a-trust-history-app-with-swift-vapor-340g

In this series, I'll describe how Wevo is built.

Let's Dive in.

Motivation

First, let me explain why I built Wevo.

As I posted before, I believe our trust history and related information should belong with us.

Trust is built from many properties.
History, Details, reactions, date... and so on.

So, I believe these information should be in our hands.

But in reality, this isn't the case.

Our trust history is locked inside platforms.

There are many options to create trust in each other.
(for example, Slack, linkedin, gmail, X(formerly Twitter), facebook..)

If you made a promise on a Slack, and if you want to move promise history to gmail?

that's not. you can't move your trust history to other services.

This is why I built Wevo.

I also had a personal problem: I couldn't remember all the appointments properly.

Make a "Real world" promise model

Organize the flow of the agreement

Next, let's talk about how I made a promise model.

In the real world, many promises follow this sequence.

One person proposes to another.
The counterparty accepts the proposal.
Both parties fulfill their duties.
The promise is fulfilled.

So, I need to create a model that can at least represent this much.

But, not every promise is fulfilled.
Some promises are not fulfilled due to some reason.

If a promise is not fulfilled, it follows this sequence instead:

One person proposes to another.
The counterparty accepts the proposal.
One of them didn't fulfill their duty.
The promise is not fulfilled.

In addition, this can also happen.

One person proposes to another.
The counterparty doesn't accept the proposal.

I also need to create models that can represent these aspects.

Naming

After organizing the promise sequences, I needed to name each state.

I named each action as follows.

Action	Description
proposed	One person proposes to another
signed	The counterparty accepts the proposal
parted	One of them rejects the proposal
honored	Mark promise as fulfilled

And named each state as follows.

State	Description
proposed	Created after proposal. Counterparty has not yet signed.
signed	Counterparty has signed.
dissolved	Counterparty rejected the proposal, or one party withdrew after signing.
completed	Both parties marked the promise as honored.

In next post, I will explain how to express agreement in a promise and how to verify its status.

Cheers! 🤙
Happy coding~ 💻😙💻

Introducing "Wevo": Building a trust history app with Swift & Vapor 🖋️

h1d3mun3 — Fri, 27 Mar 2026 15:12:48 +0000

Hello everyone :p
I'm h1d3mun3, an iOS Developer from Japan.🍎📱

I've made my repository to public just a moment ago. 🎉
It's designed to create portable, reliable, and flexible trust history in each other. 🖋️

Trust, in most services, is stored inside the service itself. Your ratings, your agreements, your track record — they live in someone else's database. When the service shuts down, or changes its rules, or you simply move on, that history disappears with it.

Wevo is an exploration of a different approach. Rather than computing a trust score, Wevo records what happened: proposals made, agreements reached, signatures given. Each event is cryptographically signed by the parties involved, stored locally on your device, and owned by you — not by a platform.

Built with Swift and Vapor.
I'd love to hear your thoughts on the architecture.
Feel free to check out the code!

https://github.com/h1d3mun3/wevo
https://github.com/h1d3mun3/wevo-space

Happy coding!

scrennshot1	scrennshot2	scrennshot3