Join

class defipy.process.Join()

Initialize a pool with both tokens. Join is the first liquidity-providing operation a pool sees: it sets the initial reserves and mints the initial LP-token supply to the user. After Join, the pool has a price and trades can happen.

Cross-protocol: dispatches to the underlying protocol implementation. Available on Uniswap V2, Uniswap V3, Balancer, and Stableswap.

Methods

apply

Join().apply(pool, user, amount0, amount1)

Add the initial token-0 and token-1 amounts to pool on behalf of user. The ratio of amount0 to amount1 sets the initial price.

Parameters

Name	Type	Description
pool	exchange	Pool instance, typically returned by a Factory.deploy(...) call.
user	str	User address (string identifier) credited with the initial LP tokens.
amount0	float	Amount of pool.token0 to deposit.
amount1	float	Amount of pool.token1 to deposit.

Returns

None. The pool is mutated in place — reserves are set, LP-token supply is minted and credited to user. Inspect pool.summary() or pool.get_liquidity() after the call.

Example

from defipy import *

user_nm = 'user'
eth_amount = 1000
tkn_amount = 100000

tkn = ERC20("TKN", "0x111")
eth = ERC20("ETH", "0x09")
exchg_data = UniswapExchangeData(tkn0 = eth, tkn1 = tkn, symbol="LP", address="0x011")

factory = UniswapFactory("ETH pool factory", "0x2")
lp = factory.deploy(exchg_data)

Join().apply(lp, user_nm, eth_amount, tkn_amount)
lp.summary()

Exchange ETH-TKN (LP) Reserves: ETH = 1000.0, TKN = 100000.0 Liquidity: 10000.0

Notes

• The implied price is amount1 / amount0. In the example above, the pool starts at 100 TKN per ETH.
• Initial liquidity is √(amount0 · amount1) for V2 and Balancer-style geometric-mean pools. For V3 and Stableswap the formula differs but the principle is the same: the first deposit sets a baseline.
• Uniswap V2 burns a small MINIMUM_LIQUIDITY to a sentinel address ("0") on first mint to prevent share-price manipulation. Treat that sentinel as out-of-band when counting LPs.

See also

• Swap — once a pool is initialized, Swap exchanges one token for the other.
• AddLiquidity — for adding liquidity to an already-initialized pool.
• Tutorials → Uniswap V2 — runnable end-to-end walkthrough.