Cotrii
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Wallet Connection Guide (using MetaMask as an example)

Paying with JPYC on Cotrii requires connecting a wallet such as MetaMask. This guide walks through setting up a wallet and connecting it to Cotrii.

What is MetaMask?

MetaMask is a free wallet app for managing blockchain-based assets. Cotrii accepts JPYC (a yen-pegged stablecoin) for plan purchases, membership sign-ups, reader support, and per-article purchases, which requires connecting a wallet like MetaMask. Other wallets that work the same way (browser extensions), such as Rabby Wallet, Coinbase Wallet, or OKX Wallet, can be used just as easily.

Supported networks

Cotrii supports two networks (chains): Kaia and Polygon. You can choose either one at payment time, and MetaMask will prompt you automatically if the network needs to be added or switched. For how to obtain JPYC itself, see the official JPYC website.

STEP 1. Install MetaMask

PC (Chrome / Edge / Firefox / Brave)

  1. Visit the official MetaMask website in your browser and install the extension via "Install MetaMask for [your browser]."
  2. After installing, click the MetaMask icon (the fox) in the top-right of your browser and follow the on-screen steps to create a new wallet or import an existing one.
  3. If creating a new wallet, write down the 12-word "Secret Recovery Phrase" shown on screen and store it somewhere safe. Never share this phrase with anyone — anyone who has it can steal your assets. Cotrii staff will never ask you for it.

Android

  1. Search for "MetaMask" on Google Play and install the official app (developer: MetaMask).
  2. Open the app and follow the on-screen steps to create a new wallet or import an existing one.
  3. As with the PC version, never share your Secret Recovery Phrase with anyone, and store it somewhere safe.

iOS (iPhone / iPad)

  1. Search for "MetaMask" on the App Store and install the official app (developer: MetaMask).
  2. Open the app and follow the on-screen steps to create a new wallet or import an existing one.
  3. As with the PC version, never share your Secret Recovery Phrase with anyone, and store it somewhere safe.

STEP 2. Connect your wallet to Cotrii

Once MetaMask is set up, connect it to Cotrii from the settings page.

Connecting on PC

  1. Log in to Cotrii in the same browser where you installed the MetaMask extension.
  2. Open Settings > Billing and click "Connect Wallet."
  3. A MetaMask popup will appear — select the account to connect, then click "Next" followed by "Connect."
  4. You'll then see a signature request. This signature only proves wallet ownership and does not move any funds. Review it and click "Sign" to complete the connection.

Connecting on Android / iOS (important)

On mobile, opening Cotrii in a regular browser like Safari or Chrome will NOT let the connect button work. You must open Cotrii from MetaMask's built-in browser.
  1. Open the MetaMask app and tap the "Browser" tab (a compass-like icon) at the bottom of the screen or in the menu.
  2. Type cotrii.com into the address bar to open Cotrii, then log in.
  3. Open the menu (top-left or top-right) and go to Settings → Billing, then tap "Connect Wallet."
  4. Review and approve the connection request and the signature request that appear.
  5. Once connected, keep using this in-app MetaMask browser to access Cotrii for JPYC payments such as article purchases or plan subscriptions.

STEP 3. Check or remove the connection

Once connected, the wallet section on Settings > Billing will show "Connected" along with your wallet address. To disconnect, use the "Unlink" button on the same page.

Common issues

"No wallet extension such as MetaMask was found"
On PC, this means the MetaMask extension isn't installed or is disabled — check your browser's extension settings. On mobile, you need to access Cotrii from MetaMask's built-in browser, not Safari or Chrome. See "Connecting on Android / iOS" above.
The wrong account gets connected
Switch to the account you want to use via the account icon in the top-right of the MetaMask extension (or app), then click "Connect Wallet" again from Cotrii's settings page.
A prompt asks me to switch networks
This is MetaMask confirming a switch to (or addition of) the Kaia or Polygon network that Cotrii uses for payment. Review the details (network name, chain ID, etc.) and select "Approve."
I lost or forgot my Secret Recovery Phrase
This is a MetaMask-side issue and cannot be recovered through Cotrii. Please check MetaMask's official support. Never share your Secret Recovery Phrase with anyone.

A security note

Cotrii and its staff will never ask you to enter or share your Secret Recovery Phrase or private key. Any email, message, or site asking for this information is a scam.