Picture this

Who it is for

Rosa Delgado runs a bakery on the west side of San Antonio and needs $8,000 for a new deck oven by June 2027, but the rate on her savings keeps moving. Fixed Jar shows her one jar: put in $7,800 today, and if she holds to June 30 she gets about $8,040, in plain words with the risks next to it. On the other side of the same market, traders who want the floating yield buy it from her jar.

Two ways to own it

What you get

Base$100

Yours in 3 to 5 days

The user app: savings jars with a plain words quote, a jar builder (amount, date, source), hold, open early and roll flows, a trader desk for the yield side, receipts, reminders and a three tier paywall with simulated USDC checkout. Runs on Pendle style pools on Arbitrum, Base and Ethereum.

You choose: accent color and jar labels
You choose: which yield sources and maturities to list
You choose: jar reminder schedule
You choose: trader desk on or off

Customfrom $1,500

Built around you

Reshape it entirely: new features, your flows, your brand end to end, integrations you need. We scope it with you.

Everything in Base
Custom features and design
Priority build

Why it is new

What exists today, and what this does differently

What is new

Principal and yield splitting is live (Pendle), and single fixed rate products exist on top of it (Sky Fixed Yield, wallet PT tabs). What is new is a market you own with two fronts on the same pools: a savings jar view that only speaks in dates and dollar amounts, a separate trader view for the yield side, and an owner curated list of which yield sources may back a jar at all.

Closest things out there

Pendle (the PT and YT market itself), Sky Fixed Yield (fixed rate on sUSDS built on Pendle), OneKey wallet PT access, Notional and Gearbox leveraged PT products.

Checked with web searches in October 2026. A search is not proof that nothing similar exists, and the market moves fast, so we recheck before every build.

What it unlocks

The human in it

Turns an interest rate derivative into a jar with a date and a dollar amount on the label, so a baker can plan an oven.

The Regatta Board

Races Fixed Jar can enter

3 live races fit this app. Each one says why, with its prize and countdown. The rule on existing code is on the race page.

Grant roundArbitrumArbitrum Foundation Grants / DAO programsFundingNot announcedRolling, apply any timeWhy it fits. Arbitrum hosts the deepest PT and YT liquidity and funds consumer DeFi fronts; check current terms.20 other apps can enter tooSee the race Grant roundBaseBase Builder GrantsFundingNot announcedRolling, apply any timeWhy it fits. A consumer savings front with smart wallet onboarding fits Base's retail push; check current terms.56 other apps can enter tooSee the race HackathonmultichainEncode Club hackathons and acceleratorsPrizeNot announcedRolling, apply any timeWhy it fits. DeFi hackathons often run fixed income tracks; check each event's rule on existing code and current terms.6 other apps can enter tooSee the race

See every race on the board

What you own

The whole app, not a starter kit.

A fixed rate savings market you own: savers fill jars with a date and an amount on the label, traders swap the yield side on their own desk, and you decide which yield sources are allowed at all.

Base price · $100

The user app, complete

Every buyer gets the same finished app. Basic branding and copy changes come through a quick form.

Illustrated home with the next jar to open and first-run onboardingHome

Three step welcome (pick a date, read the label, know the risks), then the shelf total and the one next action.

Jar builder with a live plain words labelFill

Amount, date and approved source; the label updates with what goes in, what comes out, the early exit price and the risks.

Simulated fill with a wallet signature stepFill

Review, sign and a receipt, with the price impact shown for the size.

Shelf of jars by dateShelf

Every jar with its tag, days left and the amount expected at the date.

Three ways a jar can goShelf

Hold to the date, open early at market price, or ride out a source warning, each with its own outcome.

Roll proposal at maturityShelf

A new jar is suggested when one opens; nothing rolls without a signature.

Yield desk for tradersDesk

Implied rate chart, buy or sell the yield side, size warnings and a plain loss example.

Receipts with hashes and the label at the timeReceipts

Fills, early exits, redemptions and swaps, each marked onchain or offchain.

Plans, reminders, permissions and visionMe

Three tier paywall with simulated USDC checkout, reminder channels, share card and invite link.

Open the full app demo

Add-on

Owner console

Your admin side: revenue, paywall editor, users, rules and the agent log.

Revenue dashboard with live paywall editorRevenue

MRR, swap fee income, a monthly chart and tier editing that updates the user app at once.

Payments and pay methodsRevenue

Recent USDC payments and which pay methods the checkout accepts.

Approved sources registrySources

Add, pause or retire yield sources with a reason, max jar size and longest date; the saver view follows instantly.

Market rulesSources

Desk fee, early exit warning threshold, minimum pool depth and reminder lead time.

Watcher agent log with costsAgent

Peg, pause and depth checks, including a failed read and how it adapted, plus monthly running costs.

Roadmap with build requestsRoadmap

v1 included, v2 and v3 add-ons with prices and a request button.

Top-up

Growth and referrals

Referral and growth mechanics, switched on when you are ready to grow.

Shelf share loop and cohortsGrowth

Jar label share cards, savings circle invites, sources of new savers and a run-a-circle simulation.

The money path, built in

How it earns for you

Savers start free and pay monthly for unlimited jars and shared shelves; traders pay for the yield desk. A small owner fee on yield desk swaps goes to your treasury and is shown on every desk receipt.

JarFreeUp to two jars, plain words labels, hold and open early, receipts.

Pantry$5 per monthUnlimited jars, shared shelf, Telegram reminders, roll proposals, monthly statement.

Yield desk$15 per monthTrader view with implied rate charts, yield side swaps, size warnings and rate alerts.

Owner fee of 0 to 0.3 percent on yield desk swaps (default 0.1 percent), shown before signing and on the receipt. Savers filling or redeeming jars pay no owner fee.

Prices are yours to set. Illustrative, not a promise of income.

Growth loops, built in

How it spreads

Jar label share cards: a date and an amount, never a percent
Savings circles and small business groups share one shelf link
Every trader on the desk deepens the pools the jars depend on
A monthly statement savers forward to a partner or accountant

Roadmap · build the next phase with us

Where it goes next

v1 included

Jars and the yield desk

Plain words jar builder on approved sources
Shelf with hold, open early and roll
Yield desk for traders
Approved sources registry and watcher
Paywall editor, payments, receipts

Included

Payroll jars and shared shelves

Jars that fill a little every payday
Shop and family shelves with roles
One shelf across Arbitrum, Base and Ethereum

Add-on from $450

Curator network

Other owners subscribe to your approved list
Public source reviews with history
White label shelves on a partner's domain

Add-on from $1,100

The pitch, ready for investors and grant reviewers

Unlocked when your app is paid in full

Your 2 minute demo script

Unlocked when your app is paid in full

Make it entirely yours

Your brand, the sources you approve, chains, maturities, jar wording and integrations such as payroll, accounting exports or a partner's white label shelf are scoped and priced together.

Custom from $1,500

BLUEPRINT

Why it matters and how it really works

The recipe (how it is built, the data, costs, risks, build order, the pitch and the demo script) is unlocked when your app is paid in full.

The need

Small business owners and careful savers want to know what they will have on a date, not a rate that moves every week. Fixed rate DeFi exists through principal tokens, but the screens speak in implied APY, PT, YT and maturities, so the people who would use it most never get past the first page.

What exists and what is new

This partly exists. Pendle splits yield bearing tokens into principal and yield sides and runs the market, Sky Fixed Yield wraps one Pendle pool in a fixed rate product, and some wallets list PT assets. Fixed Jar is your own front on that kind of market: savers see jars with a date and a dollar amount on the label, traders get a separate desk for the yield side, and you, the owner, decide which yield sources are allowed to back a jar. Research verdict: the mechanism exists, the savings front and owner curation are the new part, medium novelty.

The data it runs on

Unlocked when your app is paid in full

1.The mission

Saving for a date should feel like filling a jar: you know what goes in, what comes out and when, and what could go wrong.

2.Why people can't resist it

The label Every jar has a tag in plain words: put in this today, get about this on that date if you hold, and the three risks that could change it.

The shelf A shelf of jars by date shows a family or a shop what lands when, with a reminder the week before each one opens.

The yield desk Traders who want the floating side get their own view with the implied rate chart, so the savers' screen stays calm.

3.How it works for real

Unlocked when your app is paid in full

4.Pricing

Cost per use: unlocked when your app is paid in full.

Jar Free

Up to two jars on approved sources, plain words labels, hold and open early, receipts.

Pantry $5 per month

Unlimited jars, a shared family or shop shelf, reminders by Telegram, roll proposals and a monthly statement.

Yield desk $15 per month

The trader view: implied rate charts, yield side swaps with size warnings, alerts when the implied rate moves.

5.Growth loop

Jar labels are shareable: 'Oven fund, $8,040 on June 30, 2027.' Small business groups and savings circles pass the shelf around, and every trader who joins the yield desk deepens the pools that make the jars work.

6.Risks and guardrails

Unlocked when your app is paid in full

7.Build order

Unlocked when your app is paid in full

8.Where this is going

Now
One shelf of jars on curated sources, a separate desk for traders, receipts for everything.
Next
Shop and family shelves, payroll jars that fill a little each week, and Base, Arbitrum and Ethereum under one shelf.
Later
Local owners run jars for their own communities, each with their own curated list and reputation for what they allow.
The world it builds
Ordinary people plan with onchain money by date and amount, with the risks written on the label instead of in the fine print.

Costs and tools are estimates at the time of writing. General information only, not legal or financial advice.

OWNER PLAYBOOK

Own it, then chart your voyage

Nine routes from one vessel. Tap a port to open its chart.

Why own Fixed Jar

Fixed rate DeFi already works, but only traders can read it. Owning Fixed Jar means you run the savings shelf on top of it: you choose which yield sources are safe enough to back a jar, savers see a date and an amount instead of an APY, and traders pay to use the yield desk on the same pools. Start with one savings circle you know, then rent your curated shelf to every group that asks how you did it.

What’s stopping you?

“I do not understand principal and yield tokens well enough to run this.”

You do not need to price them. The app reads prices from the market and writes the label. Your job is curation: which sources you trust, how long a jar may run and how big. The Sources screen is a short form, and the delivery guide walks through one source end to end.

“What if a source fails and my savers lose money?”

It can happen, and the app says so on every label. Your protection is fewer, better sources, a watcher that pauses new jars when a peg or pool breaks a rule, and plain warnings to holders. Never promise a result, and never call a jar insured.

“Is this a regulated savings product where I live?”

It might look like one. Many owners run it for a known group with clear risk wording, take local advice before marketing widely and avoid words like guaranteed, insured or deposit account. The app is built without those words on purpose.

“Nobody will pay for a front end when Pendle is free.”

Traders already use Pendle; your savers never would. People pay for the shelf, reminders and curation, and traders pay for a calmer desk with size warnings. Start with one group where you are the trusted person, not with the whole market.