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, "~> 0.9"}
  ]
end

Documentation: hexdocs.pm/onchain_tempo.

Modules

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 (polls for confirmation 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

Which endpoint serves what

This package is Tempo-specific by design — it is not portable to an arbitrary Ethereum provider, and that is the point rather than an oversight. Type-0x76 transactions, TIP-20 encoding, and the synchronous broadcast path are Tempo protocol features; a generic Ethereum endpoint has no notion of them. What you can swap is which Tempo-compatible endpoint you point at — your own node, or a provider serving the Tempo chain — not the chain itself.

Every RPC function takes an rpc_url so you can target either network per call. The faucet additionally reads a TEMPO_RPC_URL environment variable as its default, falling back to https://rpc.moderato.tempo.xyz — set it to point the faucet at a different Moderato endpoint without threading a URL through every call (Onchain.Tempo.Faucet.rpc_url/0 returns the resolved value).

0x76 verification

Signing and canonical encoding are checked against the provider-owned Tempo transaction spec and the current ox TypeScript SDK (TxEnvelopeTempo), plus live Moderato broadcast success and a relevant decode error. Evidence lives in priv/verification/0x76/ (ledger, ox vectors, live observation). Unit tests under test/onchain/tempo/verification/ rerun the properties, differential checks and mutation campaign; live checks are the :integration suite.

License

MIT