Docs/How it works

Smart contracts

The three contracts behind Scarf on Base Sepolia.

Addresses#

Contract	Address	Role
Scarf	0x0382…AE43	Profiles, conversations, messages, media, payments
Forwarder	0x61d6…fCf1	Verifies signed requests (ERC-2771)
ScarfPaymaster	0xA3bF…5F4f	Relays requests and refunds the relayer

Chain ID 84532. Built with Solidity 0.8.28 and OpenZeppelin, deployed with Hardhat Ignition.

Scarf#

Main functions

Function	What it does
`registerUser(publicKey, username)`	Creates your profile.
`createConversation(participants, keyHash)`	Creates a conversation with 2+ registered participants.
`sendMessage(recipient, hash, token, amount, ipfsHash, mediaType, size, text)`	Sends a message, file and/or payment.
`sendBatchMessages(…)`	Sends up to 10 messages in one call.
`deleteMessage(messageId)`	Marks a message deleted (sender or recipient only).
`updatePublicKey(newKey)`	Replaces your profile's public key.

Events

UserRegistered, ConversationCreated, MessageSent, BatchMessageSent, MediaUploaded, PaymentSettled, MessageDeleted.

Limits

Constant	Value
`MAX_FILE_SIZE`	50,000,000 bytes (50 MB)
`MAX_STORAGE_PER_USER`	1,000,000,000 bytes (1 GB)
`MAX_MESSAGES_PER_USER`	10,000
Batch size	10 recipients

Forwarder#

OpenZeppelin's MinimalForwarder. It checks the EIP-712 signature and nonce of a ForwardRequest, then calls the target with the signer's address appended, which Scarf reads as the sender.