Private Transfers

This guide covers sending tokens privately between privacy addresses using the Privacy Boost CLI.

CLI Command

privacy-boost send \
  --token 0x4200000000000000000000000000000000000006 \
  --amount 0.1 \
  --recipient 0x04...194-char-privacy-address \
  --human

Output:

Building proof... (this may take a moment)
Proof generated successfully
Transfer submitted!
Transaction: 0x9abc...def0
Amount: 0.1 ETH
Recipient: 0x04ab...ef01 (privacy address)

Command Parameters

Flag	Required	Description
`--token`	Yes	Token contract address
`--amount`	Yes	Amount to send
`--recipient`	Yes	Recipient’s 194-character privacy address
`--human`	No	Interpret amount as human-readable (default: wei)

Paying Several Recipients at Once

send-batch pays every recipient from one set of input notes, in a single request: one fee instead of one per recipient, and one epoch slot instead of several. Repeat --to once per recipient.

privacy-boost send-batch \
  --token 0x4200000000000000000000000000000000000006 \
  --to 0x04...alice:0.1 \
  --to 0x04...bob:0.25 \
  --human

Flag	Required	Description
`--token`	Yes	Token contract address
`--to`	Yes	`<recipient>:<amount>`, repeatable. Recipient is a 194-character privacy address or a 42-character Ethereum address
`--human`	No	Interpret amounts as human-readable (default: wei)
`--decimals`	No	Decimals for `--human` parsing (default: 18)

The whole batch resolves to one request id, printed the same way send prints its result.

How many recipients fit

The server proves a fixed set of (inputs, outputs) shapes, and a transfer has to fit inside one of them. Its output count is your recipient count plus a change note, so a longer recipient list leaves room for fewer input notes:

Outputs (recipients + change)	Input notes that can be spent
1-2	up to 15
3-11	up to 4

So 5 inputs by 3 outputs is not provable, even though 15 inputs and 11 outputs are each individually fine. In practice: past two recipients, the transfer has to be coverable by at most four notes. Consolidate fragmented notes first if a batch is rejected with UNSUPPORTED_TRANSFER_SHAPE, or split the payout across two batches.

Programmatic Usage (Rust)

let result = sdk.send(
    "0x4200000000000000000000000000000000000006",
    "100000000000000000", // 0.1 tokens in wei
    "0x04...recipient-privacy-address",
)?;
println!("Transfer TX: {}", result.tx_hash);
println!("Fee: {}", result.fee);

Multi-recipient sends take (recipient, amount) pairs:

let result = sdk.send_batch(
    "0x4200000000000000000000000000000000000006",
    &[
        ("0x04...alice".to_string(), "100000000000000000".to_string()),
        ("0x04...bob".to_string(), "250000000000000000".to_string()),
    ],
)?;

TransferResult

pub struct TransferResult {
    pub tx_hash: String,
    pub fee: String,
}

Privacy Address Validation

Validate the recipient address before sending:

if !sdk.is_valid_privacy_address(recipient) {
    println!("Invalid privacy address");
    return;
}

let result = sdk.send(token_address, amount, recipient)?;

Address Lookup

Look up a user’s privacy address:

let identity = sdk.resolve_identity("0x...wallet-address")?;
println!("Privacy address: {}", identity.privacy_address);

sdk.send(token_address, amount, &identity.privacy_address)?;

Error Handling

match sdk.send(token_address, amount, recipient_privacy_address) {
    Ok(result) => println!("Transfer TX: {}", result.tx_hash),
    Err(CliError::InsufficientBalance) => println!("Not enough shielded balance"),
    Err(CliError::InvalidAddress) => println!("Invalid privacy address"),
    Err(CliError::NotAuthenticated) => println!("Please login first"),
    Err(CliError::NetworkError { message }) => println!("Network error: {}", message),
    Err(e) => println!("Transfer failed: {:?}", e),
}

Best Practices

1. Validate Addresses Before Sending

Always validate the privacy address before attempting a transfer.

2. Check Balance After Transfer

privacy-boost send --token $TOKEN --amount 0.1 --recipient $PRIVACY_ADDR --human
privacy-boost balance --token $TOKEN

Quickstart

Setup

SDKs

Transfers

Private Transfers

CLI Command

Command Parameters

Paying Several Recipients at Once

How many recipients fit

Programmatic Usage (Rust)

TransferResult

Privacy Address Validation

Address Lookup

Error Handling

Best Practices

1. Validate Addresses Before Sending

2. Check Balance After Transfer

Next Steps

​Private Transfers

​CLI Command

​Command Parameters

​Paying Several Recipients at Once

​How many recipients fit

​Programmatic Usage (Rust)

​TransferResult

​Privacy Address Validation

​Address Lookup

​Error Handling

​Best Practices

​1. Validate Addresses Before Sending

​2. Check Balance After Transfer

​Next Steps

Private Transfers

CLI Command

Command Parameters

Paying Several Recipients at Once

How many recipients fit

Programmatic Usage (Rust)

TransferResult

Privacy Address Validation

Address Lookup

Error Handling

Best Practices

1. Validate Addresses Before Sending

2. Check Balance After Transfer

Next Steps