An open protocol for graded cards

A slab's cert number is its address.

Make an offer on any graded slab by the number on its label, from any chain. The holder accepts in one transaction: the slab goes to you, the USDC goes to them. No marketplace account, no venue lock-in, nobody in the middle.

Read the standard How it works

Look one up — live on Polygon

→ key 0x9543…183f · the same on every chain

Grader and number from the label — PSA, CGC, CSG, BGS, SGC or TAG.

How it works

Three steps, all on chain.

Tokenized slabs live inside custodians — Courtyard on Polygon, Collector Crypt on Solana. Today an offer on one is an account bidding inside one venue. Revere keys everything to the one identifier every venue already agrees on: the cert.

The cert becomes a key

keccak256("CGC:6149683293") — the grader and the number from the label, in one canonical form. The same 32 bytes on Polygon, Base, Ethereum and Solana.

An attestation finds the token

An attester reads a custodian's token and states on chain which cert it holds. Anyone can attest; each client picks whom to trust. Who holds the slab is never stored — it's read from the token when you ask.

The holder accepts in one transaction

A buyer escrows USDC for the cert, funded here or from any chain over Circle CCTP. The holder sends the token to the escrow: the slab goes to the buyer, the USDC to the seller, or nothing moves at all.

Build on it

Any client with a contract library can read it.

No API key, no server of ours in the path. If revere.fi went dark tomorrow, every slab, attestation and offer would still be readable from the chain.

The standard. Graders, cert keys, locations, attestations, offers and events — with test vectors. STANDARD.md
The escrow. No owner, no admin key, no upgrade, no pause, no fee. Source verified byte for byte. Sourcify
The library. resolve, certKey, parseCert — MIT, runs in Node and the browser. Source

import { resolve } from "@revere/sdk";

const slab = await resolve("CGC 6149683293", { client });

// {
//   certId: "CGC:6149683293",
//   slabs: [{
//     custodian: "courtyard",
//     location:  "eip155:137/erc721:0x251b…/1400…8522",
//     holder:    "0x0f92…1406",   // read live
//     status:    "held",
//   }]
// }

Status

What's live, and what isn't.

The escrow is live so it can be used with small amounts while the rest is built. It has not been audited. Don't escrow more than you'd be comfortable losing until an audit is published here.

Part	State	Where
Standard	Draft v0	STANDARD.md
Attestations (EAS, Polygon)	Live	schema 0xa3c4…8efb
Escrow (Polygon, CCTP v2)	Live · unaudited	0xc3b6…1a8b
First settlement	1 Oct 2026	A Courtyard CGC 10 for 1 USDC, in one transaction
Solana escrow (Collector Crypt)	Not started	—

Why Revere

Plating that protects, and adds to what it covers.

In 1801 Paul Revere built America's first copper-rolling mill, and in 1803 his sheet copper sheathed the hull of the USS Constitution — the ship that took cannon fire in 1812 and came out Old Ironsides. A slab does the same for a card: a hard case and a number that make it worth more than the bare card.

And to revere something is to hold it in high regard. That's what grading is for.