`blk`

Ethereum and Web3 client - JSON-RPC calls, wallet key-pairs, transaction signing, ABI encoding, IPFS add/get, and ENS name resolution.

Load with: use blk

What this module does

blk is an Ethereum/EVM client. You point it at a JSON-RPC endpoint (Infura, Alchemy, a local node, etc.) and can then check balances, send transactions, call smart contracts, estimate gas, and query blocks. It also has a simple wallet (key-pair generation and message signing), basic ABI encoding for uint256 and address parameters, IPFS add/get via the HTTP API, and ENS name resolution.

Quick example

use blk

# Connect to a node
c = ethne("https://mainnet.infura.io/v3/YOUR_KEY")

# Check an account balance
bal = ethgb(c, "0xYourAddress")
prn(bal)

# Generate a wallet
w = walne()
prn(walad(w))  # derived public address

# Sign a message
sig = walsg(w, "hello")

# Create and sign a transaction
tx = txne(walad(w), "0xRecipient", 1000000, nil)
tx = txsg(tx, w.ac)

# Get current gas price
prn(ethgg(c))

Functions

JSON-RPC client

ethne(url)

Creates a client pointing at the given JSON-RPC URL. Sets an incrementing request ID counter starting at 1.

ethcl(c, method, params)

Makes a JSON-RPC call. Sends a POST request with {jsonrpc: "2.0", id, method, params}, increments the ID counter, and returns the result field. Returns nil on HTTP error or JSON-RPC error.

Account and chain

ethgb(c, addr)

Gets the ETH balance of addr at the latest block via eth_getBalance.

ethec(c, tx)

Sends a raw transaction object via eth_sendTransaction. Returns the transaction hash.

ethgs(c, txhash)

Gets a transaction receipt for the given hash via eth_getTransactionReceipt.

ethnb(c)

Returns the current block number via eth_blockNumber.

ethg0(c, n)

Gets a full block by number (with transaction objects) via eth_getBlockByNumber.

Gas

ethgg(c)

Returns the current gas price via eth_gasPrice.

ethge(c, tx)

Estimates the gas required for a transaction via eth_estimateGas.

Smart contracts

ethcc(c, binary_addr, abi)

Creates a contract instance from a deployed address and an ABI list. Returns a contract object that holds the client, address, and ABI.

ethc0(contract, method, params)

Calls a contract function (read-only, no gas) via eth_call. Encodes the call data using blknc.

ethcs(contract, method, params, account)

Sends a state-changing transaction to a contract method via eth_sendTransaction. Encodes call data using blknc.

blknc(abi, method, params)

Encodes a contract call. Looks up the function in the ABI by name, computes the 4-byte function selector (first 4 bytes of keccak256(signature) via cry.sh4), and encodes each parameter - uint256 as a zero-padded 64-character hex string, address with the 0x prefix stripped and zero-padded to 64 characters.

Wallet

walne()

Generates a new wallet with a 32-byte random private key via cry.cryrn.

walad(w)

Derives the public address from the wallet's private key via cry.cryfp.

walsg(w, msg)

Signs a message with the wallet's private key (SHA-256 of private key + message via cry.sh256, then signs with cry.crys2).

Transactions

txne(from, to, value, data)

Creates a transaction object with default gas limit 21000, gas price "0x1", and nonce 0. data defaults to "0x" if nil.

txsg(tx, priv_key)

Signs a transaction by computing SHA-256 of from + to + value + data and signing with cry.crys2. Sets tx.sg. Returns the updated transaction.

IPFS

ipfsn(url)

Creates an IPFS client pointing at the given API URL (e.g. "http://localhost:5001").

ipfsd(c, data)

Adds data to IPFS via the /api/v0/add endpoint. Returns the content hash (CID), or nil on failure.

ipfsg(c, hash)

Retrieves content from IPFS by hash via /api/v0/cat?arg=hash. Returns the content, or nil on failure.

ENS

ensre(c, name)

Resolves an ENS name to an address via the ens_resolver JSON-RPC method. Returns the addr field of the response, or nil.

Notes

ABI encoding only handles uint256 and address parameter types - other types (strings, arrays, tuples, etc.) are not implemented.
All JSON-RPC errors return nil - check your node endpoint and parameters if you get unexpected nils.
Transaction signing uses cry.sh256 and cry.crys2 - this is a simplified signing scheme and is not compatible with standard Ethereum ECDSA signing (EIP-155).
Requires trl, txt, cry, and req.