Cross-Chain Access SDK — API Reference

Full technical reference for all classes, methods, models, and exceptions in the Cross-Chain Access SDK.

→ User Guide

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CrossChainAccessClient

Location: swarm/cross_chain_access_sdk/sdk/client.py

Main entry point. Orchestrates authentication, market validation, on-chain USDC transfers, and order submission.

Constructor

CrossChainAccessClient(
    network: Network,
    private_key: str,
    user_email: Optional[str] = None,
    rpc_url: Optional[str] = None,
    is_dev: bool = False,
)

Attributes: network, is_dev, cross_chain_access_api (CrossChainAccessAPIClient), web3_helper (Web3Helper), auth (SwarmAuth), usdc_address, topup_address

Raises: ValueError if USDC is not available on the specified network.

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authenticate()

async def authenticate() -> None

Signs an EIP-191 authentication message with the wallet and obtains an access token. Called automatically when using async with.

Raises: AuthenticationError

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check_trading_availability()

async def check_trading_availability() -> tuple[bool, str]

Validates all prerequisites for trading.

Returns: (is_available: bool, message: str)

Checks performed (in order):

1. Market hours (14:30–21:00 UTC, Monday–Friday)
2. Account not blocked
3. Trading not suspended
4. Transfers not restricted
5. Market is open

Possible messages:

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get_quote()

async def get_quote(rwa_symbol: str) -> Quote

Returns: Quote

• rate: ask price (for buys) or bid price (for sells)
• source: "cross_chain_access"
• timestamp: current time

Raises: QuoteUnavailableException, InvalidSymbolException

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buy()

async def buy(
    rwa_token_address: str,
    rwa_symbol: str,
    user_email: str,
    rwa_amount: Optional[Decimal] = None,
    usdc_amount: Optional[Decimal] = None,
    target_chain_id: Optional[int] = None,
) -> TradeResult

Trade flow:

1. Validate market hours and account status
2. Fetch real-time quote
3. Calculate amounts with 1% slippage protection
4. Validate buying power
5. Transfer USDC to escrow on-chain
6. Submit order to Cross-Chain Access API
7. Send email confirmation

Returns: TradeResult

Raises: ValueError, MarketClosedException, AccountBlockedException, InsufficientFundsException, QuoteUnavailableException, OrderFailedException

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sell()

async def sell(
    rwa_token_address: str,
    rwa_symbol: str,
    user_email: str,
    rwa_amount: Optional[Decimal] = None,
    usdc_amount: Optional[Decimal] = None,
    target_chain_id: Optional[int] = None,
) -> TradeResult

Parameters identical to buy(). Provide either rwa_amount (shares to sell) or usdc_amount (target USDC to receive).

Trade flow:

1. Validate market hours and account status
2. Fetch real-time quote
3. Calculate amounts with 1% slippage protection
4. Validate RWA token balance
5. Transfer RWA tokens to escrow on-chain
6. Submit order to Cross-Chain Access API
7. Send email confirmation

Returns: TradeResult

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close()

async def close() -> None

Closes HTTP clients. Called automatically with async with.

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CrossChainAccessAPIClient

Location: swarm/cross_chain_access_sdk/cross_chain_access/client.py

HTTP client for the Cross-Chain Access API. Accessible via client.cross_chain_access_api.

get_account_status()

async def get_account_status() -> AccountStatus

Returns the account's current trading permissions and restrictions.

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get_account_funds()

async def get_account_funds() -> AccountFunds

Returns buying power and cash balances.

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get_asset_quote()

async def get_asset_quote(symbol: str) -> CrossChainAccessQuote

Fetches the raw bid/ask quote from the stock exchange for symbol.

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create_order()

async def create_order(
    symbol: str,
    side: OrderSide,
    quantity: Decimal,
    notional: Optional[Decimal],
    rwa_token_address: str,
    user_email: str,
    target_chain_id: Optional[int],
) -> CrossChainAccessOrderResponse

Submits a buy or sell order to the Cross-Chain Access API.

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MarketHours

Location: swarm/cross_chain_access_sdk/market_hours/market_hours.py

Utility class for US stock market timing.

Market schedule

• Open: 14:30 UTC (9:30 AM EST)
• Close: 21:00 UTC (4:00 PM EST)
• Days: Monday–Friday
• Closed: weekends and US market holidays

is_market_open()

@staticmethod
def is_market_open() -> bool

Returns True if the market is currently open.

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time_until_open()

@staticmethod
def time_until_open() -> timedelta

Returns the time remaining until the next market open.

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time_until_close()

@staticmethod
def time_until_close() -> timedelta

Returns the time remaining until market close (only meaningful when market is open).

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get_market_status()

@staticmethod
def get_market_status() -> tuple[bool, str]

Returns (is_open: bool, human_readable_message: str). Message examples:

• "Market is open. Closes in 3h 15m"
• "Market is closed. Opens in 8h 30m"

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Data models

Quote

Shared with the Trading SDK. See Trading SDK API Reference — Data Models.

For Cross-Chain Access quotes: source = "cross_chain_access", rate = ask price for buys, bid price for sells.

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TradeResult

Shared with the Trading SDK. See Trading SDK API Reference — Data Models.

For Cross-Chain Access results: source = "cross_chain_access".

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OrderSide

class OrderSide(str, Enum):
    BUY = "buy"
    SELL = "sell"

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AccountStatus

Location: swarm/cross_chain_access_sdk/cross_chain_access/models.py

Methods: is_trading_allowed() -> bool — returns True only if all restrictions are clear.

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AccountFunds

Location: swarm/cross_chain_access_sdk/cross_chain_access/models.py

Methods: has_sufficient_funds(required_amount: Decimal) -> bool

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CrossChainAccessQuote

Raw quote from the stock exchange.

Methods: get_price_for_side(side: OrderSide) -> Decimal — returns ask for BUY, bid for SELL.

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CrossChainAccessOrderResponse

Methods: to_dict() -> dict

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Exceptions

Exception hierarchy

CrossChainAccessException (base)
├── MarketClosedException
├── AccountBlockedException
├── InsufficientFundsException
├── QuoteUnavailableException
├── OrderFailedException
└── InvalidSymbolException

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Supported networks

USDC addresses are automatically configured per source network. The target_chain_id for delivery can be any EVM-compatible network.

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Rate limits & performance

• Quote latency: near real-time via API
• Order processing: near real-time (settlement depends on blockchain confirmation time)
• Retry logic: 3 attempts, exponential backoff — 1s, 2s, 4s
  • Retried: network timeouts, 5xx errors, 429 rate limits
  • Not retried: 4xx client errors (bad parameters, auth failures)