# Deposits & withdrawals

Deposit addresses, trading withdraws, internal transfers, lifecycle, and chain helpers.

## How funds move

| Flow               | How                                                             |
| ------------------ | --------------------------------------------------------------- |
| External → funding | Deposit address route configured to stop in Funding             |
| External → trading | Deposit address route configured to continue to Trading         |
| Funding → funding  | On-chain Funding Account transfer                               |
| Funding → trading  | On-chain `TradingGateway.deposit` via `chain` (not ConnectRPC)  |
| Funding → external | On-chain `FundingAccount.withdrawToChain` plus Zipper fee quote |
| Trading → funding  | `client.withdraw.create_to_funding` (signed intent)             |
| Trading → external | `client.withdraw.create_to_external_chain`                      |
| Trading → trading  | `client.internal_transfers.create`                              |

Also: Zipper config (`client.zipper`), lifecycle reads/streams (`client.lifecycle`), address book for destinations.

Product overview: [Funds & Transfers](https://testnet.polyester.com/docs/developer-docs/funds-transfers/overview).

## Deposit addresses

```python
addr = await client.deposit.create_address(chain_id=1)
listed = await client.deposit.list_addresses(chain_id=1)
```

See [Deposit](https://testnet.polyester.com/docs/sdk/python/reference/deposit).

## Trading withdraws

API-key bots pass a precomputed `payload_signature` (no browser wallet signer on this SDK):

```python
from polyester import new_trading_withdraw_idempotency_key, new_trading_withdraw_nonce

idempotency_key = new_trading_withdraw_idempotency_key()
nonce = new_trading_withdraw_nonce()
# Persist both values and use them when producing signature_bytes.
result = await client.withdraw.create_to_funding(
    asset_id=2,
    quantity="100.00",
    payload_signature=signature_bytes,
    idempotency_key=idempotency_key,
    nonce=nonce,
)
```

Reuse the same idempotency key, nonce, and signed payload on retry. Details: [Withdrawals](https://testnet.polyester.com/docs/sdk/python/reference/withdrawals).

## Internal transfers

```python
await client.internal_transfers.create(
    asset_id=2,
    quantity="10",
    idempotency_key="xfer-1",
    destination_subaccount_id="123",
)
```

## On-chain Funding helpers

```python
from polyester.chain import (
    POLYESTER_TESTNET_ENVIRONMENT,
    PolyesterSmartAccount,
    encode_trading_gateway_deposit,
)

account = PolyesterSmartAccount(owner_private_key="0x...")  # your EOA
deposit = encode_trading_gateway_deposit(
    trading_gateway=POLYESTER_TESTNET_ENVIRONMENT.contracts.trading_gateway_address,
    u_asset_id="0x...",
    quantity_scaled=10**18,
)
account.send_calls([deposit])
```

Full surface: [Chain helpers](https://testnet.polyester.com/docs/sdk/python/reference/chain).

> **Security**
>
> High-risk money movement may require additional account controls. See [Withdrawals & transfers security](https://testnet.polyester.com/docs/developer-docs/authentication-security/withdrawals-and-transfers-security).