cctp

Small Trezor-backed CLI for bridging USDC with cctp-rs.

The first supported route is Ethereum mainnet to HyperEVM. The CLI uses Alloy's Trezor signer support and defaults to waiting for any permissionless relayer to complete the destination mint.

Install

cargo install cctp

The source repository, published crate, and installed command are all named cctp.

Usage

export ETHEREUM_RPC_URL="https://..."
export HYPEREVM_RPC_URL="https://..."

cctp bridge \
  --amount 10.25 \
  --recipient 0x0000000000000000000000000000000000000000

By default this sends standard-finality CCTP v2 transactions. To request fast finality, provide an explicit fee cap:

cctp bridge \
  --amount 10.25 \
  --fast \
  --max-fee-usdc 0.01

By default the CLI waits for any relayer to complete the mint on HyperEVM. It uses a read-only HyperEVM provider and does not initialize a destination signer or require HyperEVM gas.

To self-relay, add --self-relay; the relay account must hold HyperEVM gas. The relay signer defaults to --trezor-account, but can be selected independently with --relay-trezor-account.

Before any signing prompt, the CLI prints each active Trezor account's role, derivation path, chain binding, and address. Use --dry-run to inspect those details without sending transactions.

Configuration

Configuration is treated as a service boundary. Raw CLI/env input is resolved once into a validated BridgeConfig; execution code consumes that immutable config instead of reading flags or environment variables directly.

Precedence is:

1. CLI flags.
2. Environment variables for RPC URLs: ETHEREUM_RPC_URL and HYPEREVM_RPC_URL.
3. TOML config file passed with --config.
4. Built-in defaults for route, wallet, account, relay mode, and transfer mode.

amount, ethereum_rpc, and hyperevm_rpc must be supplied by CLI, env, or config file. Example:

amount = "10.25"
ethereum_rpc = "https://..."
hyperevm_rpc = "https://..."
recipient = "0x0000000000000000000000000000000000000000"
trezor_account = 0
fast = false
self_relay = false
dry_run = false

Run with:

cctp bridge --config cctp.toml --amount 25

Domain primitives are shared with cctp-rs where they belong. The CLI uses CctpV2Route for route validation and UsdcAmount for six-decimal USDC amount parsing. Wallet backends, RPC endpoints, dry-run behavior, and relay policy stay in the CLI because they are application concerns.