OnchainTempo

Tempo blockchain primitives for Elixir — 0x76 transaction handling, TIP-20 token encoding, RPC broadcasting, and TransferWithMemo event parsing.

Built on onchain.

Installation

def deps do
  [
    {:onchain_tempo, "~> 0.2"}
  ]
end

Documentation: hexdocs.pm/onchain_tempo.

Modules

Module	Purpose
Onchain.Tempo.TIP20	TIP-20 function selectors, calldata encoders, Tempo constants
Onchain.Tempo.Transaction	0x76 transaction struct, deserialize, payment matching, fee payer co-signing
Onchain.Tempo.Transaction.Builder	Build and sign 0x76 transactions from scratch
Onchain.Tempo.RPC	Tempo JSON-RPC operations (broadcast async/sync, fetch receipt)
Onchain.Tempo.Transfer	TransferWithMemo event log parsing
Onchain.Tempo.Faucet	Moderato testnet faucet — tempo_fundAddress wrapper (testing only)

Quick Start

Deserialize a Tempo transaction

{:ok, tx} = Onchain.Tempo.Transaction.deserialize("0x76...")
tx.chain_id  #=> 42431
tx.calls     #=> [%{to: <<...>>, value: 0, input: <<...>>}]

Find a payment call

{:ok, match} = Onchain.Tempo.Transaction.find_payment_call(tx, token_address,
  amount: "1000000",
  recipient: "0x70997970..."
)
match.amount  #=> 1000000

Build and sign a transfer

{:ok, tx_hex} = Onchain.Tempo.Transaction.Builder.build_signed_transfer(
  private_key: "0xac09...",
  token: "0x20c0...",
  recipient: "0x7099...",
  amount: 1_000_000,
  chain_id: 42_431,
  rpc_url: "https://rpc.moderato.tempo.xyz"
)

Broadcast

# Async (returns tx hash immediately)
{:ok, tx_hash} = Onchain.Tempo.RPC.broadcast_async(tx_hex, rpc_url)

# Sync (waits for block inclusion, returns receipt)
{:ok, tx_hash, receipt} = Onchain.Tempo.RPC.broadcast_sync(tx_hex, rpc_url)

Fund a Moderato testnet wallet

For integration tests against Moderato (testnet 42_431), Onchain.Tempo.Faucet wraps the non-standard tempo_fundAddress JSON-RPC:

# Fund an existing address.
{:ok, [tx_hash | _]} = Onchain.Tempo.Faucet.fund_address("0xabc...")

# Generate + fund a fresh keypair (waits for settlement before returning).
{:ok, %{private_key: priv, address_hex: hex, address_bin: bin}} =
  Onchain.Tempo.Faucet.fresh_funded_wallet()

Defaults to https://rpc.moderato.tempo.xyz; overridable via TEMPO_RPC_URL or by passing rpc_url: in the opts (e.g. fund_address("0xabc...", rpc_url: "https://my-mirror")). Mainnet does not support tempo_fundAddress.

Discovery

All modules use descripex:

OnchainTempo.describe()                          # Module overview
OnchainTempo.describe(:transaction)              # Function list
OnchainTempo.describe(:transaction, :deserialize) # Full details

Tempo Networks

Network	Chain ID	RPC URL
Mainnet	4217	https://rpc.tempo.xyz
Moderato (testnet)	42431	https://rpc.moderato.tempo.xyz

License

MIT