Paidline

Public marketplace · payment checker

List work.Anyone can buy it.

A public board of things for sale. Buyers send USDC on Ethereum. Attestcoin proves the transfer. A Creditcoin contract is the only thing that may say it is paid.

Looking is free. Wallet only when you list or pay.

Live listings

See all

How it works

Four steps. Then it’s paid.

You do not need to operate two chains. List. Pay. The contract checks. Other apps ask isPaid.

  1. 01Creditcoin

    List

    Attach the work, the exact USDC price, and a small Creditcoin lock. The work stays sealed.

  2. 02Ethereum

    Pay

    A buyer sends that USDC from any wallet. Paidline never holds it.

  3. 03Attestcoin

    Prove

    A Merkle proof of that transfer is submitted. The submitter has no opinion.

  4. 04isPaid

    Confirm

    The listing is paid. Checkout unlocks the work. Other contracts can ask.

What this is not

A checker. Not a custodian.

  • Not a bridge

    USDC never moves to Creditcoin. Only the fact of payment does.

  • Not escrow of the dollars

    The seller is paid on Ethereum. The lock is a receipt bond.

  • Not a private board

    Every funded listing is public. First matching payment claims it.

Who it’s for

Sellers, buyers, agents, and other apps.

  • Sellers

    Put a retainer, a seat, or an API credit on the board. You do not pick the buyer. USDC lands in your wallet.

    Create a listing

  • Buyers

    Open the marketplace. Send USDC the way you already send it. First match wins the listing.

    See what’s for sale

  • Agents

    Call an API. If it’s unpaid you get HTTP 402 and a pay link. After payment, the same call returns 200 and the work.

    Try the API

  • Other apps

    Don’t rebuild payments. Ask the contract if a listing is paid, then unlock the work.

    Read the docs

Questions

If you’re new here

Do I need a special wallet?
No, to look. To list, connect a Creditcoin wallet. To pay, send USDC from the Ethereum wallet you already have.
Who receives the USDC?
The seller. Paidline never holds the dollars. The buyer receives the Creditcoin that was locked against the listing.
What if two people pay?
The first matching payment the contract accepts wins. A second transfer of the same amount is not a second listing.
Why two chains?
Buyers live on Ethereum. The listing and the “paid” flag live on Creditcoin. Paidline is the checker between them.

Start with a listing.

Publish it. It appears on the marketplace. The first matching payment confirms it.