Onchain

Shared Ethereum/blockchain library for Elixir. Provides read (eth_call) and write (transaction signing) capabilities using signet as the sole Ethereum dependency.

Installation

Add onchain to your list of dependencies in mix.exs:

def deps do
  [
    {:onchain, github: "ZenHive/onchain"}
  ]
end

Requires an Ethereum JSON-RPC endpoint. Configure via:

# config/config.exs
config :signet, :rpc_url, "https://eth-mainnet.g.alchemy.com/v2/YOUR_KEY"

Or pass the URL per-call to Onchain.RPC functions.

Modules

Core

Module	Purpose
Onchain.Hex	Hex encoding/decoding (hex<->binary, hex<->integer, 0x prefix)
Onchain.ABI	ABI encoding/decoding for contract calls
Onchain.Address	Address validation, EIP-55 checksum, normalization
Onchain.Decimal	Decimal precision helpers (to_decimal, div_pow10, to_basis_points)
Onchain.RPC	Ethereum JSON-RPC wrapper (eth_call, send_raw_transaction, receipts, nonces)
Onchain.Block	Block fetching with parsed fields, timestamp-based binary search
Onchain.Contract	Generic contract read helper
Onchain.Multicall	Batch multiple eth_call via Multicall3
Onchain.Log	Event log parsing
Onchain.Signer	Key management and transaction signing
Onchain.ERC20	ERC-20 read (balanceOf, allowance) and write (transfer, approve)

Aave v3

Module	Purpose
Onchain.Aave.Pool	Pool read + write calls (getUserAccountData, supply, borrow, repay)
Onchain.Aave.Oracle	Asset price oracle + Chainlink
Onchain.Aave.Math	USD conversion, LTV, health factor, ray math
Onchain.Aave.Contracts	Verified address registry (Ethereum mainnet)
Onchain.Aave.UIPoolDataProvider	Reserves and user reserves data

Discovery

All modules use descripex for self-describing APIs:

Onchain.describe()                  # Module overview
Onchain.describe(:hex)              # Function list
Onchain.describe(:hex, :decode)     # Full function details

Testing

mix test                    # Unit tests (no RPC needed)
mix test --include integration  # Integration tests (requires RPC)

Integration tests require an Ethereum RPC endpoint:

export ETHEREUM_API_URL="https://eth-mainnet.g.alchemy.com/v2/YOUR_KEY"

License

MIT