leafage-py

Leafage reads on-chain state at a specified chain and block. Run these examples in a Chaintable Notebook. For Function usage, see Data access. The source contains the full implementation.

Create a block context

from leafage import ChainState

block = ChainState.get_block_by_height('eth', 25939934)
chain = ChainState('eth', block['id'])

`ChainState(chain_id, block_id)`

Parameter	Type	Description
`chain_id`	`str`	Chain ID, such as `eth` for Ethereum mainnet
`block_id`	`str`	Block ID at which to read state

Returns a ChainState object. For consistent multiple reads, first resolve a block ID and then reuse the same object.

Block queries

These are class methods, called directly on ChainState.

Interface	Parameters	Return value
`get_latest_block(chain_id)`	Chain ID	Latest block dictionary
`get_block_by_height(chain_id, block_height)`	Chain ID and integer height	Matching block dictionary
`get_block_by_id(chain_id, block_id)`	Chain ID and block ID	Matching block dictionary
`check_block_is_valid(chain_id, block_id)`	Chain ID and block ID	Block validity as `bool`

Block dictionaries include id, height, and timestamp. timestamp is Unix time in seconds. Additional fields may vary by chain.

Account state

wallet = '0xd8da6bf26964af9d7eed9e03e53415d37aa96045'
balance_wei = chain.get_address_balance(wallet)
print(balance_wei)

Interface	Parameters	Return value
`chain.get_address_balance(addr)`	Address string	Python `int` in the native token’s smallest unit; wei for ETH
`chain.get_address_code(addr)`	Contract address	Bytecode string starting with `0x`
`chain.get_storage_at(addr, slot)`	Address and storage slot, such as `'0x0'`	Storage value string starting with `0x`
`ChainState.get_address_nonce(chain_id, addr)`	Chain ID and address	Latest nonce as Python `int`

get_address_nonce() uses the latest block, so it does not return a historical nonce from the chain object’s context. The other three instance methods use that object’s block context.

Single contract call

`chain.call(contract, method, payload, from_addr=None)`

Parameter	Description
`contract`	Contract address
`method`	Signature with input and output types, such as `balanceOf(address)(uint256)`
`payload`	Positional argument list; use `[]` for no arguments
`from_addr`	Optional caller address for the simulated call context

Returns decoded values. Multiple outputs can be unpacked; integers are Python int values.

pool = '0xb4e16d0168e52d35cacd2c6185b44281ec28c9dc'
reserve_usdc, reserve_weth, timestamp = chain.call(
    pool, 'getReserves()(uint112,uint112,uint32)', []
)

This reads or simulates a contract call. It does not send a transaction to the chain.

Batch contract calls

usdc = '0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48'
values = (
    chain.contract(usdc)
    .method('symbol()(string)', 'decimals()(uint8)')
    .payload([], [])
    .values()
)
print(values)

The output is ['USDC', 6].

Builder step	Parameters and result
`contract(*contracts)`	One or more contract addresses
`method(*methods)`	One or more method signatures; contracts and methods cannot both have multiple entries
`payload(*payloads)`	Positional argument lists for each call; empty lists may be omitted for calls with no arguments
`from_addr(addr)`	Set the caller address
`options(raise_on_error=False)`	Allow failed entries to return `None`; by default, call errors raise exceptions
`values()`	Return a list of results
`zip(*keys)`	Return an iterator pairing keys with results
`dict(*keys)`	Return a dictionary using caller-supplied keys

For example, replace .values() with .dict('symbol', 'decimals') to get {'symbol': 'USDC', 'decimals': 6}.

State overrides

set_block_overrides(value) and set_state_overrides(value) set block and account-state overrides for simulated calls. The corresponding get_*_overrides() methods return current settings. Overrides affect simulated reads without changing on-chain state. See the Leafage source for field definitions and full examples.

Overview

Quickstart

Guides

Reference

Create a block context

`ChainState(chain_id, block_id)`

Block queries

Account state

Single contract call

`chain.call(contract, method, payload, from_addr=None)`

Batch contract calls

State overrides

​Create a block context

​ChainState(chain_id, block_id)

​Block queries

​Account state

​Single contract call

​chain.call(contract, method, payload, from_addr=None)

​Batch contract calls

​State overrides

Create a block context

`ChainState(chain_id, block_id)`

Block queries

Account state

Single contract call

`chain.call(contract, method, payload, from_addr=None)`

Batch contract calls

State overrides