o2-sdk 0.2.0

Python SDK for the O2 Exchange — a fully on-chain order book DEX on the Fuel Network

O2 SDK for Python

Official Python SDK for the O2 Exchange — a fully on-chain order book DEX on the Fuel Network.

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Installation

pip install o2-sdk

Or install from source:

pip install -e sdks/python

Requires Python 3.10+.

Quick Start

Recommended first integration path on testnet:

1. Create/load owner wallet
2. Call setup_account() (idempotent setup + faucet mint attempt on testnet/devnet)
3. (Optional) Call top_up_from_faucet() for an explicit testnet/devnet top-up
4. Create session
5. Place orders
6. Read balances/orders
7. Settle balances back to your trading account after fills; order funds are moved into the market contract during execution and should be swept after fills or cancellations

import asyncio
from o2_sdk import Network, O2Client, OrderSide


async def main():
    client = O2Client(network=Network.TESTNET)
    owner = client.generate_wallet()

    account = await client.setup_account(owner)
    await client.top_up_from_faucet(owner)
    await client.create_session(owner=owner, markets=["fFUEL/fUSDC"])

    order = await client.create_order("fFUEL/fUSDC", OrderSide.BUY, "0.02", "50")
    print(f"order tx={order.tx_id}")

    balances = await client.get_balances(account.trade_account_id)
    fusdc = balances.get("fUSDC")
    print(f"fUSDC balance={fusdc.trading_account_balance if fusdc else 0}")

    settle = await client.settle_balance("fFUEL/fUSDC")
    print(f"settle tx={settle.tx_id}")

    await client.close()


asyncio.run(main())

get_balances(trade_account_id) is an aggregated view across trading account and market contracts, so settle_balance(...) does not necessarily change aggregate totals.

Network Configuration

Default network configs:

Network	REST API	WebSocket	Fuel RPC	Faucet
Network.TESTNET	https://api.testnet.o2.app	wss://api.testnet.o2.app/v1/ws	https://testnet.fuel.network/v1/graphql	https://fuel-o2-faucet.vercel.app/api/testnet/mint-v2
Network.DEVNET	https://api.devnet.o2.app	wss://api.devnet.o2.app/v1/ws	https://devnet.fuel.network/v1/graphql	https://fuel-o2-faucet.vercel.app/api/devnet/mint-v2
Network.MAINNET	https://api.o2.app	wss://api.o2.app/v1/ws	https://mainnet.fuel.network/v1/graphql	none

API rate limits: https://docs.o2.app/api-endpoints-reference.html#rate-limits.

Use a custom deployment config:

from o2_sdk import NetworkConfig, O2Client

client = O2Client(
    custom_config=NetworkConfig(
        api_base="https://my-gateway.example.com",
        ws_url="wss://my-gateway.example.com/v1/ws",
        fuel_rpc="https://mainnet.fuel.network/v1/graphql",
        faucet_url=None,
    )
)

[!IMPORTANT] Mainnet note: there is no faucet; account setup requires an owner wallet that already has funds deposited for trading. SDK-native bridging flows are coming soon.

Wallet Security

• generate_wallet() / generate_evm_wallet() use cryptographically secure randomness and are suitable for mainnet key generation.
• For production custody, use external signers (KMS/HSM/hardware wallets) instead of long-lived in-process private keys.
• See docs/guides/external_signers.rst for production signer integration.

Wallet Types and Identifiers

Why choose each wallet type:

• Fuel-native wallet — best for interoperability with other apps in the Fuel ecosystem.
• EVM wallet — best if you want to reuse existing EVM accounts across chains and simplify bridging from EVM chains.

O2 owner identity model:

• O2 owner_id is always a Fuel B256 (0x + 64 hex chars).
• Fuel-native wallets already expose that directly as b256_address.
• EVM wallets expose both:
  • evm_address (0x + 40 hex chars)
  • b256_address (0x + 64 hex chars)
• For EVM wallets, b256_address is the EVM address zero-left-padded to 32 bytes:
  • owner_b256 = 0x000000000000000000000000 + evm_address[2:]

Identifier usage:

Context	Identifier
Owner/account/session APIs	owner_id = wallet b256_address
Trading account state	trade_account_id (contract ID)
Human-visible EVM identity	evm_address
Markets	pair ("fFUEL/fUSDC") or market_id

owner_id vs trade_account_id:

• owner_id is wallet identity (b256_address) used for ownership/auth and session setup.
• trade_account_id is the trading account contract ID used for balances/orders/account state.
• setup_account(wallet) links these by creating/fetching the trading account for that owner.

Features

• Trading — Place, cancel, and manage orders with automatic price/quantity scaling
• Dual-Mode Numeric Inputs — Pass human values ("0.02", 100.0) or explicit raw chain integers (ChainInt(...))
• Strongly Typed — Enums for order sides/types, dataclasses for actions and order parameters
• Market Data — Fetch order book depth, recent trades, OHLCV candles, and ticker data
• WebSocket Streams — Real-time depth, order, trade, balance, and nonce updates via async for
• Wallet Support — Fuel-native and EVM wallets with session-based signing
• Batch Actions — Submit up to 5 typed actions per request (cancel + settle + create in one call)
• Error Handling — Typed exceptions (O2Error, InvalidSignature, RateLimitExceeded, etc.)

API Overview

Method	Description
generate_wallet() / load_wallet(pk)	Create or load a Fuel wallet
generate_evm_wallet() / load_evm_wallet(pk)	Create or load an EVM wallet
setup_account(wallet)	Idempotent account setup (create + fund + whitelist)
top_up_from_faucet(owner)	Explicit faucet top-up to the owner's trading account (testnet/devnet)
create_session(owner, markets)	Create a trading session
create_order(market, side, price, qty)	Place an order (price/qty accept human or ChainInt)
cancel_order(order_id, market)	Cancel a specific order
cancel_all_orders(market)	Cancel all open orders
settle_balance(market)	Settle filled order proceeds
actions_for(market)	Build typed market actions with fluent helpers
batch_actions(actions)	Submit typed action batch (MarketActions or MarketActionGroup)
get_markets() / get_market(pair)	Fetch market info
get_depth(market) / get_trades(market)	Order book and trade data
get_balances(account) / get_orders(market, account)	Account data
stream_depth(market)	Real-time order book stream
stream_orders(account) / stream_trades(market)	Real-time updates
withdraw(owner, asset, amount)	Withdraw funds

See AGENTS.md for the complete API reference with all parameters and types.

Guides

• docs/guides/identifiers.rst
• docs/guides/trading.rst
• docs/guides/market_data.rst
• docs/guides/websocket_streams.rst
• docs/guides/error_handling.rst
• docs/guides/external_signers.rst

Examples

Example	Description
quickstart.py	Connect, create a wallet, place your first order
market_maker.py	Two-sided quoting loop with cancel/replace
taker_bot.py	Monitor depth and take liquidity
portfolio.py	Multi-market balance tracking and management

Run an example:

python examples/quickstart.py

Testing

Unit tests (no network required):

pytest tests/ -m "not integration" -v

Integration tests (requires O2_PRIVATE_KEY env var):

O2_PRIVATE_KEY=0x... pytest tests/test_integration.py -m integration -v --timeout=120

Integration tests reuse cached wallets in sdks/python/.integration-wallets.json (gitignored) and only faucet when balances are below a conservative threshold, which improves repeat-run speed.

AI Agent Integration

See AGENTS.md for an LLM-optimized reference covering all methods, types, error codes, and common patterns.