Web3 × Exercise Supplement

The Web3 foundation
behind ESPL

Money and rules run on the same layer — infrastructure that makes behavior change implementable.

ESPL is an everyday smartphone app, but what powers it is the Web3 (blockchain) layer. The sponsorship, the promise, and the distribution rules are all implemented as smart contracts on a blockchain, so money and rules live on the same layer. The sponsorship itself is denominated in on-chain stablecoins like JPYC.

This page lays out the Web3 infrastructure that lets ESPL work — wallets, tokens, NFTs, supported chains, Web3Auth — at a depth a first-time reader can follow.

Web3 in 3 minutes

Just three things, first

ESPL doesn't use Web3 to sell complex technology. It's to keep the sponsorship's money flow transparent and free from human discretion. In everyday use you'll barely notice Web3 is there.

  • You don't need to think about the wallet

    In everyday use — walking, recording steps, joining a challenge — Web3 stays out of the way. The wallet is created automatically at signup, and Web3Auth manages the private key in a distributed way.

  • Web3 is used here for money transparency

    We use smart contracts and JPYC so that holding the sponsorship, judging success or failure, and distributing it to recipients all run in a way that doesn't bend to human convenience.

  • Failure isn't how the operator profits

    If a goal is missed, the sponsorship does not become the operator's revenue. It's automatically distributed to the recipient set up front — back to other challenges, refunded to the supporter, etc.

Reassurance

  • Personal information is not stored on-chain (steps, names, etc. live off-chain).
  • The sponsorship is designed not to flow to the operator.
  • You can start small — there's no need to stake an uncomfortable amount.

What's below is for readers who want to go a level deeper.

Read more

01 / What is Web3

The three pieces of Web3

To use ESPL, only three things are worth knowing. This isn't a full Web3 tour — it's the minimum needed to understand what's happening inside the app.

  • Distributed ledger

    A system that keeps the same record in sync across computers around the world. No single operator can rewrite it on a whim or quietly delete entries.

  • Smart contract

    A “rule program” that runs on the blockchain. It executes the conditions for the sponsorship and its distribution automatically, with no human in the loop.

  • Wallet

    Your own purse on the blockchain. It holds tokens like JPYC and NFTs that record your walking achievements.

02 / Wallet

A wallet is your own purse

A wallet is where tokens like JPYC and NFTs that record your walking achievements live. In ESPL, Web3Auth creates one automatically — no special steps needed.

  1. The private key is the real thing

    A wallet, underneath, is a long private-key string. Only the person who holds the key can move the contents of the wallet.

  2. Auto-created at signup

    In ESPL, the wallet is created automatically when you create an account. You don't need any Web3 background to get going.

  3. No seed phrase to memorize

    The “twelve-word memo” crypto wallets traditionally need is gone here. Social login takes its place.

  4. Exportable to MetaMask

    If you want to, you can export the private key and use the same wallet from another app like MetaMask. You aren't locked in.

03 / Token & NFT

The tokens and NFTs ESPL uses

ESPL supports the three Ethereum-side token standards — amount, commemorative, and bulk distribution — each used for a different role.

  • 01 / ERC-20

    Fungible token

    Currency-like tokens — including JPYC — that represent an “amount”. One coin is interchangeable with another. Sponsorship and distribution use this standard.

  • 02 / ERC-721

    Non-fungible token (NFT)

    Tokens that are unique one-by-one. Used for things like walking achievement certificates or serialized commemorative badges where uniqueness matters.

  • 03 / ERC-1155

    Multi-token

    A hybrid standard that can mint many tokens against a single ID. Suited to efficient distribution, such as a season-limited badge handed out at scale.

The actual ERC-20 token ESPL uses as the unit of sponsorship and distribution is JPYC (a yen-denominated stablecoin). The reasoning and role are on the JPYC page.

04 / Supported Chains

Supported blockchains

ESPL supports multiple chains. Depending on the challenge or campaign, tokens and NFTs are distributed on the appropriate network.

Mainnet

  • Polygon

    An L2 where JPYC circulates broadly. Low fees — ESPL's main stage.

  • Soneium

    A Sony-aligned Ethereum L2. Strong fit with Japan-originated projects.

  • Astar

    A Japan-born multi-chain platform.

  • Ethereum

    The most battle-tested L1. Used for foundational settlement and asset management.

  • BSC Mainnet

    BNB Smart Chain. An option for overseas users.

Testnet

  • Amoy

    Polygon's testnet.

  • Sepolia

    Ethereum's testnet.

Testnets are used to verify new features and for developer testing. Tokens on a testnet have no real-world value.

05 / Web3Auth

Get into crypto
without a seed phrase

“Create a wallet” usually means writing a 12-word seed phrase on paper and putting it in a safe. ESPL hands that step off to Web3Auth.

Web3Auth doesn't store the wallet's private key in one place. It splits it into multiple shares kept in different locations — a model called MPC (multi-party computation). The private key only functions when the shares are combined.

Before — Traditional wallet

Private key
(one)

Stored in
one place

⚠ Leaks once, drained forever

⚠ Lose it and there's no recovery

After — Web3Auth (ESPL)

Share 1

Social Login

Share 2

Device

Share 3

Web3Auth Net

Private key reconstructed (ephemeral)

✓ One leaks — nothing moves

✓ One lost — the rest still recover it

What each share is

Where the three shares actually live

  • Share 1 / Social Login

    Unlocked by an account you already have

    Logging in with Google / Apple / X — accounts you already use — extracts Share 1. You don't need to memorize a new password, and each provider's authentication (including 2FA) just works.

    If you lose this account, the remaining two shares can recover it.

  • Share 2 / Device

    Stored on your device

    Share 2 lives in the encrypted storage on the device you're using ESPL on (iPhone / Android / PC). It uses OS-provided protected areas such as iOS Keychain or Android Keystore.

    If you lose the device, the remaining two shares can recover from another device.

  • Share 3 / Web3Auth Network

    Held by a distributed node network

    Share 3 is held by a network of distributed nodes run by Web3Auth. Within the network it's further secret-shared, so no single operator can reconstruct the private key.

    Even if ESPL itself went offline, users could recover their assets on their own.

What Web3Auth gives us

  • No seed phrase to memorize — social login takes its place.
  • Lose the device and you can recover from another one.
  • The operator can't hold the private key alone — even if the service goes down, users can recover their assets.
  • If you want to, export the private key and use it from MetaMask or another wallet.

06 / Money Flow

How the sponsorship flows

In ESPL, the sponsorship moves along a smart contract. Stake → Walk → Distribute — all three are recorded on the blockchain.

  1. 01 / Deposit

    The Sponsor stakes the sponsorship

    When the Sponsor creates a challenge, the sponsorship is staked into a smart contract. Once staked, no one can pull it out at will — it's only distributed by the rules.

  2. 02 / Walk

    The Challenger reports steps

    During the challenge, the Challenger's daily steps flow to the smart contract. Progress is recorded on the blockchain and cannot be rewritten after the fact.

  3. 03 / Distribute

    The sponsorship reaches the recipient

    When the challenge ends, the sponsorship is distributed automatically to the pre-set recipient — whether the goal was met or missed. You can configure the recipient as the walker, family, a charity, the Sponsor, and so on.

Every stake — who staked, when, under what rule, when it was distributed — stays on the blockchain. The operator can't rewrite it after the fact, or confiscate it unilaterally.