Agent3 Passport

Verified cross-chain events become a Creditcoin passport, then a credit line.

A Sepolia transaction is proved with Attestcoin (Merkle inclusion + continuity). Creditcoin’s native verifier at 0x0000000000000000000000000000000000000FD2 must return true or CreditPassport.stamp reverts. Verified repayments open PassportLine. Anything else is refused, with a sentence.

Track: AI (an attestor that processes cryptographically verified cross-chain data). DeFi is the consumption surface, not the product.

Live: https://agent3-passport-production.up.railway.app
Repo: https://github.com/agent3-666/agent3-passport

Attestcoin — where it is used

1. Wait for attestors — ProofBuilder.waitUntilHeightAttested (or skip when on-chain latest height already covers the tx).
2. Build the proof — ProofBuilder.getProof at https://prover.cc3-testnet.creditcoin.network (/api/v1/proof-by-tx/{chainKey}/{tx}).
3. Verify — SDK PrecompileBlockProver.verifySingle → precompile verify / verifyAndEmit at 0x0FD2.
4. Stamp — CreditPassport.stamp calls verifier.verifyAndEmit(...) and require(verified, "Attestcoin: inclusion proof rejected").
5. Line — PassportLine.quote / borrow read only those stamps.

Source chain: Ethereum Sepolia. chainKey is Creditcoin’s internal id, not the EVM chainId. Confirmed via PrecompileChainInfoProvider.getSupportedChains(): Sepolia is chainKey 1 (chainId 11155111). Ethereum mainnet is chainKey 3 on this testnet.

Ten-minute path

1. npm install at repo root and in apps/passport.
2. npm run attestor (port 4201).
3. npm run dev (Next.js on 4200).
4. Open http://localhost:4200. The booklet is the product.
5. Prove → use the filled public Sepolia tx (already attested) → inspector explains Merkle vs continuity.
6. Hire the attestor with the same hash. It runs the same rail and stamps on Creditcoin when the proof verifies.
7. Line page quotes from verified repayments and can borrow. Anything else is refused, with a sentence.

# Proof rail (no funds). Calls 0x0FD2 via eth_call.
npx tsx scripts/prove-tx.ts
npx tsx scripts/prove-tx.ts 0x<sepolia_tx>

# Contracts
forge test -vv

# App
npm run attestor
npm run dev --prefix apps/passport

Contracts

Piece	Chain	Role
RepaymentLedger	Ethereum Sepolia	recordRepayment(bytes32,uint256) emits RepaymentRecorded
CreditPassport	Creditcoin CC3 testnet	stamp only if 0x0FD2 returns true
PassportLine	Creditcoin CC3 testnet	credit = sum of verified repay amounts; explicit refuse otherwise
Native verifier	Creditcoin	0x0000000000000000000000000000000000000FD2

Addresses: contracts/ADDRESSES.md. Deploy (needs faucet keys, never committed):

forge script script/Deploy.s.sol:DeploySepolia --rpc-url sepolia --broadcast
forge script script/Deploy.s.sol:DeployCreditcoin --rpc-url creditcoin --broadcast

Verified proof (no CTC required)

Public Sepolia tx 0x975051aef8615c48573c5b6cd270c3aad3101325511da54943e85ea15d74b7e4 (height 11442024). The public Sepolia node prunes receipts this old, so the UI says so rather than asserting a status it cannot read.

• chainKey 1 (confirmed)
• Merkle siblings: 7
• Continuity roots: 77
• verifySingle → true against 0x0FD2 (eth_call)

Run it yourself against the live deployment:

curl -s -X POST https://agent3-passport-production.up.railway.app/api/prove \
  -H 'Content-Type: application/json' \
  -d '{"txHash":"0x975051aef8615c48573c5b6cd270c3aad3101325511da54943e85ea15d74b7e4"}'
# → "attested": true, "verified": true

Negative control

A verification that always passes proves nothing, so the same proof is resubmitted with one byte of txBytes flipped:

npm run negative-control
# 1. Genuine proof  -> accepted
# 2. Tampered proof -> rejected (execution reverted: "Merkle proof validation failed")

The precompile refuses the forged proof. Script: scripts/negative-control.ts.

The rail, end to end on chain

Step	Chain	Transaction
Repayment recorded	Sepolia	0x8234a9e3331ab9ce8407e9922afc4ef44b1e01938f388aeb379db254ba589465
Passport stamped	Creditcoin	0x01f1efc1c4bf8beb7d47c8be1f576ce4260def7f5c815105a45d060dad8b1d8b
Line drawn	Creditcoin	0x65a19ca2abc996cf83364324e4e61e31f2bfdf2b31bf4b84776cec623d2447a4

Deployed: CreditPassport 0x88FEB78da56beB5Fd3af6655160907de0fAF09Fd and PassportLine 0x11C9c3d5f400735387ACBA51aeeC03566eaE77FC on Creditcoin CC3, RepaymentLedger 0x88FEB78da56beB5Fd3af6655160907de0fAF09Fd on Sepolia.

Read the resulting credit line without a wallet:

curl "https://agent3-passport-production.up.railway.app/api/credit?address=0x8e5830D9Cc2c88A330698A6B334ACF9c07c2acD4"

Environment

• Creditcoin CC3 testnet RPC: https://rpc.cc3-testnet.creditcoin.network (chainId 102031)
• Explorer: https://creditcoin-testnet.blockscout.com/
• Proof API: https://prover.cc3-testnet.creditcoin.network/
• Sepolia RPC: https://ethereum-sepolia-rpc.publicnode.com
• Official decoder (tutorial env; passport does not require it): 0x731c345d79Fb8BbDC541f9DF3b6317585F849F9f

Copy .env.example to .env for optional keys. Do not commit keys.