Seisa

Seisa means scrutiny in Japanese. Keep scrutiny over your finances.

Why did i build this?

• If you're not from india, we do a lot, like a lot of daily expenses digitally through UPI.
• I like to spend, but I also like to know how and where I spend.
• Right now I keep track of finances or it's automatically done via axio.
• TBH, this is one of the best written software I've ever used. It's all automatic and works quite well.
• And there is enough flexibility to manage transactions. Like we can change date, categorize, add notes, etc.
• But it's a little out of context, i.e. because it's automatic, transaction descriptions and meta info is not always accurate.
• And because it's "AUTOMATIC", I don't want to go and change tracked transactions. I mean that defeats the whole purpose right ?
• Then, If I'm going to track and put info by myself, why not make the whole process manual.
• But I also don't want to do it in a spreadsheet. That's too much work.
• So I thought, why not build a simple ledger, that has tailored UI to commit expenses fast.

What do I expect from the app ?

• Privacy and Speed, The app should store all data in my device. And it should open/close fast.
• Simple, I don't want BS. Like It should be one time setup and then just commit expenses.
• I want to be able to commit expenses fast, like really fast. I mean I open it, I add expense, short note and that's it.
• I also want a place to analyze my expenses. Like how much I spent on food, travel, etc. charts, graphs, etc.
• I want to be able to export my data, like in CSV or something.
• instead of putting proper meta, I should have tags, where I can choose some tags and commit.
• I may want to sync data across devices, but that's not a priority. Axio doesn't do it, and I'm fine with it.
• I should be able to see monthly allowance. Let's say I choose 30k monthly. I want to see how much I've spent and how much is left.
• I should be able to see how much I've spent on a particular day, week, month, year, etc.
• There should be all shorts of views, e.g. how much spent on a tag, how much spent on a tag in a month, etc.

High level design

• App has 4 basic constructs. Check Schema for more details.
  • Account
  • Income
  • Expense
  • Transaction
• When users onboard
  • Setup account
  • Setup income
  • Setup expense
• Once all setup, user can start committing transactions

For more details see

• Excalidraw board
• Draw.io board

High level impl.

• Data
  • Data is stored as a SQLite3 DB in user's device.
  • It uses something called Origin Private File System (OPFS) to store the DB.
  • The thing about OPFS is it's not exposed to user. i.e. you can't modify it from devtools.
  • This way data never leaves user's device.
• Data handling
  • Data is queried and mutated via kysely
• UI
  • Vue is my first love. It's simple and fast.
  • All data that comes from DB is stored in a massive reactive store. I tried to follow Mobx store pattern.
  • The store is deep reactive. So this way each data point or object can be expressed via a model. Then updating the model will update all of it's references.
• Distribution
  • Bundled with Vite.
  • App is a PWA. So it can be installed on any device. and it's offline first.
  • You literally just need to be online to get app updates. that's it.

For more details

• API, it's not exactly an API server but more like a data store
• How data is handled in UI

Tech decisions

• Why so complicated data setup? A normal LocalStorage based setup would've been enough.
  • The issue with LocalStorage or IndexedDB is that it's open. i.e. you can modify it from devtools.
  • Also JSON based data is faster to read but harder to query, modify and put relations.
  • i.e. with a relational DB, you can filter with various conditions, you can join tables, etc. much easily with a good query builder. see Kysely.
  • Also, I wanted to try out OPFS. It's a new thing and I wanted to see how it works.