Blockchain Support

Supported blockchains, wallets, and token verification details.

Supported Blockchains

Blockchain	Status	Signature Standard
Cardano	✅ Fully Supported	CIP-30 / CIP-8
Ethereum	🔜 Coming Soon	EIP-191 (personal_sign)
Solana	🔜 Coming Soon	Ed25519

Note: We are currently only supporting Cardano. Ethereum and Solana support will be available in the coming days.

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Cardano

Supported Wallets

Wallet	ID	Status
Eternl	eternl	✅ Recommended
Nami	nami	✅ Supported
Flint	flint	✅ Supported
Yoroi	yoroi	✅ Supported
Lace	lace	✅ Supported
Typhon	typhoncip30	✅ Supported
GeroWallet	gerowallet	✅ Supported
NuFi	nufi	✅ Supported

Signature Standard: CIP-30

TAGBASE uses the CIP-30 standard for wallet communication and CIP-8 for message signing.

Signing Process:

// 1. Enable wallet
const api = await window.cardano.eternl.enable();

// 2. Get address (hex-encoded)
const addresses = await api.getUsedAddresses();
const addressHex = addresses[0];

// 3. Convert message to hex
const messageHex = Buffer.from(message).toString('hex');

// 4. Sign using signData (returns COSE_Sign1)
const { signature, key } = await api.signData(addressHex, messageHex);

Response Format:

Field	Description
signature	COSE_Sign1 signature (hex)
key	COSE_Key public key (hex)

Address Formats

TAGBASE accepts both formats and normalizes automatically:

Format	Example
Bech32	addr1qx2kd28nq8ac5pr...
Hex	019bd6451e65b9f5...

Token Holder Verification

For Cardano native tokens, TAGBASE verifies:

1. Signature validity — Cryptographic proof the wallet signed the message

2. Token ownership — The wallet (or any address under the same stake key) holds the token

Stake Key Matching:

Cardano wallets often use multiple payment addresses under a single stake key. TAGBASE handles this by:

1. Looking up the stake address for the signing address

2. Fetching all payment addresses linked to that stake key

3. Checking if any of those addresses hold the required token

Signing Address → Stake Key → All Payment Addresses → Token Holder Check

Token Data Requirements

For holder verification, tokens must have:

Field	Required	Description
asset_id	Yes	Policy ID + Asset Name (hex)
policy_id	Optional	Token policy ID
fingerprint	Optional	CIP-14 asset fingerprint

Note: Blockfrost API is used for on-chain token holder lookups.

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Ethereum (Coming Soon)

Planned Wallet Support

• MetaMask

• WalletConnect

• Coinbase Wallet

• Rainbow

• Trust Wallet

Signature Standard: EIP-191

// personal_sign message signing
const signature = await ethereum.request({
  method: 'personal_sign',
  params: [message, address]
});

Token Standards

Planned support for:

• ERC-721 (NFTs)

• ERC-1155 (Multi-tokens)

• ERC-20 (Fungible tokens)

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Solana (Coming Soon)

Planned Wallet Support

• Phantom

• Solflare

• Backpack

Signature Standard

Ed25519 message signing via Solana wallet adapters.

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Verification Message Format

All blockchains use the same message structure:

Tagbase Ownership Verification

Verification ID: VRF_abc123def456
Nonce: 7a9c3f2e-1234-5678-abcd-ef0123456789
Expires: 2024-01-15T10:35:00.000Z

Component	Purpose
Verification ID	Links signature to specific product
Nonce	Prevents replay attacks
Expires	5-minute validity window

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Security Model

What Gets Verified

Check	Description
Signature validity	Cryptographic proof of wallet control
Message integrity	Signed message matches challenge
Expiry check	Challenge not older than 5 minutes
Token ownership	Wallet holds the required token

What's NOT Required

• No transaction fees (signing is free)

• No private key exposure

• No on-chain transactions

• No token transfers

Privacy

• Wallet addresses are masked in public responses (e.g., addr1q...x7k4)

• Full addresses stored securely for verification

• No wallet balances or other assets are accessed

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Network Requirements

Blockchain	Network
Cardano	Mainnet only
Ethereum	Mainnet (planned)
Solana	Mainnet (planned)

Testnet signatures are not accepted for production verifications.

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Troubleshooting

Issue	Cause	Solution
"Token not in wallet"	Token held by different address	Use wallet containing the token
"Signature verification failed"	Message mismatch or invalid signature	Retry with fresh challenge
"Challenge expired"	More than 5 minutes elapsed	Request new challenge
Wallet not detected	Extension not installed/enabled	Install and enable wallet extension
Wrong network	Connected to testnet	Switch wallet to mainnet

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API Endpoints Summary

Endpoint	Blockchain	Purpose
POST /verifications/{id}/challenge	All	Get signing challenge
POST /verifications/{id}/proof	Cardano	Submit CIP-30 proof
POST /verifications/{id}/proof	Ethereum	Submit EIP-191 proof