Betfair
Founded in 2000, Betfair operates the world’s largest online betting exchange, with its headquarters in London and satellite offices across the globe.
PoseiTrader provides an adapter for integrating with the Betfair REST API and Exchange Streaming API.
Installation
Install PoseiTrader with Betfair support via pip:
pip install --upgrade "posei_trader[betfair]"
To build from source with Betfair extras:
uv sync --all-extras
Examples
You can find live example scripts here.
Betfair documentation
For API details and troubleshooting, see the official Betfair Developer Documentation.
Application Keys
Betfair requires an Application Key to authenticate API requests. After registering and funding your account, obtain your key using the API-NG Developer AppKeys Tool.
See also the Betfair Getting Started - Application Keys guide.
API credentials
Supply your Betfair credentials via environment variables or client configuration:
export BETFAIR_USERNAME=<your_username>
export BETFAIR_PASSWORD=<your_password>
export BETFAIR_APP_KEY=<your_app_key>
export BETFAIR_CERTS_DIR=<path_to_certificate_dir>
We recommend using environment variables to manage your credentials.
Overview
The Betfair adapter provides three primary components:
BetfairInstrumentProvider: loads Betfair markets and converts them into Posei instruments.BetfairDataClient: streams real-time market data from the Exchange Streaming API.BetfairExecutionClient: submits orders (bets) and tracks execution status via the REST API.
Capability Matrix
Betfair operates as a betting exchange with unique characteristics compared to traditional financial exchanges:
Order Types
| Order Type | Betfair | Notes |
|---|---|---|
MARKET | - | Not applicable to betting exchange. |
LIMIT | ✓ | Orders placed at specific odds. |
STOP_MARKET | - | Not supported. |
STOP_LIMIT | - | Not supported. |
MARKET_IF_TOUCHED | - | Not supported. |
LIMIT_IF_TOUCHED | - | Not supported. |
TRAILING_STOP_MARKET | - | Not supported. |
Execution Instructions
| Instruction | Betfair | Notes |
|---|---|---|
post_only | - | Not applicable to betting exchange. |
reduce_only | - | Not applicable to betting exchange. |
Time-in-Force Options
| Time-in-Force | Betfair | Notes |
|---|---|---|
GTC | - | Betting exchange uses different model. |
GTD | - | Betting exchange uses different model. |
FOK | - | Betting exchange uses different model. |
IOC | - | Betting exchange uses different model. |
Advanced Order Features
| Feature | Betfair | Notes |
|---|---|---|
| Order Modification | ✓ | Limited to non-exposure changing fields. |
| Bracket/OCO Orders | - | Not supported. |
| Iceberg Orders | - | Not supported. |
Configuration Options
The following execution client configuration options affect order behavior:
| Option | Default | Description |
|---|---|---|
calculate_account_state | True | If True, calculates account state from events. |
request_account_state_secs | 300 | Interval for account state checks in seconds (0 disables). |
reconcile_market_ids_only | False | If True, only reconciles orders for configured market IDs. |
ignore_external_orders | False | If True, silently ignores orders not found in cache. |
Configuration
Here is a minimal example showing how to configure a live TradingNode with Betfair clients:
from posei_trader.adapters.betfair import BETFAIR
from posei_trader.adapters.betfair import BetfairLiveDataClientFactory
from posei_trader.adapters.betfair import BetfairLiveExecClientFactory
from posei_trader.config import TradingNodeConfig
from posei_trader.live.node import TradingNode
# Configure Betfair data and execution clients (using AUD account currency)
config = TradingNodeConfig(
data_clients={BETFAIR: {"account_currency": "AUD"}},
exec_clients={BETFAIR: {"account_currency": "AUD"}},
)
# Build the TradingNode with Betfair adapter factories
node = TradingNode(config)
node.add_data_client_factory(BETFAIR, BetfairLiveDataClientFactory)
node.add_exec_client_factory(BETFAIR, BetfairLiveExecClientFactory)
node.build()