lse-data 0.9.0

Python SDK for London Strategic Edge real-time market data, historical candles, and paper-account trading

lse-data

Python SDK for London Strategic Edge real-time market data.

Stream live prices for 4,000+ instruments including stocks, crypto, forex, indices, commodities, ETFs, and 81,000+ options contracts.

Install

pip install lse-data

Command-line (easiest)

After install, save your key once and use the lse command anywhere:

lse auth lse_live_xxxxxxxxxxxx

# Fetch 30 days of gold 1h candles
lse candles XAU/USD --days 30 --timeframe 1h

# Write 5 years of gold 1m to CSV
lse candles XAU/USD --start 2021-01-01 --end 2026-01-01 --timeframe 1m --csv gold_5y.csv

# Stream live ticks
lse stream XAU/USD BTC/USD AAPL

# Browse the symbol catalog
lse catalog --category commodity

Quick start

from lse import LSE

client = LSE(api_key="your_api_key")

for tick in client.stream(["BTC/USD", "AAPL", "EUR/USD"]):
    print(f"{tick.symbol}: ${tick.price}")

Get your API key at londonstrategicedge.com/data.

Features

• Historical OHLCV candles for 4,000+ instruments (REST, no WebSocket needed)
• Real-time WebSocket streaming with auto-reconnect
• 4,000+ symbols: US/UK/EU/Asia stocks, crypto, forex, indices, commodities, ETFs
• 81,000+ option contracts via subscribe_options()
• Symbol catalog API for discovery before subscribing
• Server-side symbol validation (invalid symbols rejected immediately)
• Dynamic subscribe/unsubscribe at runtime
• Graceful disconnect (from callbacks or other threads)
• Sync and async interfaces
• Callback and iterator patterns
• Paper-account trading via BrueTrading (MetaTrader-style 12-digit api_key, no JWT)
• Zero config, just an API key

Paper-account trading

Each paper account on the LSE platform is auto-issued a 12-digit api_key at creation. That key alone is the credential for trading the account, the same way MetaTrader's expert advisor login number works. Use it for strategy bots, CI runners, or your own desktop terminal.

from lse import BrueTrading

trading = BrueTrading("047382910556")    # 12-digit key from /paper-trading

trading.buy("EUR/USD", 1, sl=1.10, tp=1.25)
trading.sell("XAU/USD", 0.5)
trading.buy_limit("EUR/USD", 1, price=1.05)

print(trading.account())                  # {'balance': ..., 'leverage': 50, ...}
for p in trading.positions():
    print(p)

trading.close_all("EUR/USD")              # flatten one symbol
trading.close_all()                       # flatten everything

Full method list: account, positions, orders, buy, sell, buy_limit, sell_limit, buy_stop, sell_stop, close, close_all. Errors raise BrueTradingError with the HTTP status preserved on the exception. Full reference: londonstrategicedge.com/docs/brue-trading.

Usage

Historical candles

Fetch OHLCV candles for any instrument. No WebSocket connection needed.

from lse import LSE

client = LSE(api_key="your_key")

# As a list of dicts
result = client.candles("XAU/USD", start="2021-01-01", end="2026-01-01", timeframe="1d")
print(f"{result['rows']} candles, plan: {result['plan']}")
for c in result["data"][-3:]:
    print(f"{c['timestamp']}  close={c['close']}")

# As a pandas DataFrame (pip install lse-data[pandas])
df = client.candles("AAPL", "2025-01-01", "2026-01-01", timeframe="1h", as_dataframe=True)
print(df.tail())

Supported timeframes: 1m, 5m, 15m, 30m, 1h, 2h, 4h, 1d

Works for all 4,000+ instruments: stocks, crypto, forex, ETFs, commodities, indices.

Large downloads with live progress

For multi-year 1m pulls (which exceed the 2M row single-call cap), pass progress=True. The SDK auto-chunks the request and shows a tqdm bar. Requires pip install lse-data[progress].

from lse import LSE

client = LSE(api_key="your_key")

df = client.candles(
    "XAU/USD",
    start="2021-01-01",
    end="2026-01-01",
    timeframe="1m",
    progress=True,
    as_dataframe=True,
)
# XAU/USD 1m: 100%|████████████| 61/61 [01:35<00:00,  1.6s/chunk]
# -> 1,872,343 rows

df.to_csv("gold_5y.csv")

Want custom chunk sizes? Pass chunk_days=30 (or any int). Defaults per timeframe: 1m=30d, 5m=180d, 15m=365d, 1h=1825d, 1d=3650d.

Stream ticks (simplest)

from lse import LSE

client = LSE(api_key="your_key")

for tick in client.stream(["BTC/USD", "ETH/USD", "AAPL"]):
    print(f"{tick.symbol:12s} ${tick.price:>12,.2f}")

Callback style

from lse import LSE

def on_tick(tick):
    print(f"{tick.symbol}: {tick.price}")

client = LSE(api_key="your_key")
client.on("tick", on_tick)
client.connect(symbols=["BTC/USD", "ETH/USD"])

Async streaming

import asyncio
from lse import LSE

async def main():
    client = LSE(api_key="your_key")
    async for tick in client.stream_async(["BTC/USD"]):
        print(tick)

asyncio.run(main())

Save to CSV

import csv, datetime
from lse import LSE

client = LSE(api_key="your_key")

with open("ticks.csv", "w", newline="") as f:
    writer = csv.writer(f)
    writer.writerow(["time", "symbol", "price", "bid", "ask"])

    for tick in client.stream(["BTC/USD", "ETH/USD"]):
        writer.writerow([
            datetime.datetime.now().isoformat(),
            tick.symbol, tick.price, tick.bid, tick.ask,
        ])

Tick object

Each tick has these fields:

Field	Type	Description
symbol	str	Instrument symbol (e.g. BTC/USD, AAPL)
price	float	Latest price
bid	float	Bid price (if available)
ask	float	Ask price (if available)
volume	float	Volume (if available)
timestamp	float	Unix timestamp
name	str	Human-readable name (e.g. Apple Inc.)

Events

When using the callback style with .on():

Event	Callback args	Description
tick	Tick	New price tick
connected	(none)	WebSocket connected
authenticated	(none)	API key accepted
disconnected	(none)	Connection lost (will auto-reconnect)
error	str	Error message

Symbol catalog

Query available instruments before subscribing. No WebSocket connection needed.

from lse import LSE

client = LSE(api_key="your_key")

# Get all available symbols
all_symbols = client.catalog()
print(f"{len(all_symbols)} instruments available")

# Filter by category: stock, crypto, forex, etf, commodity, index
stocks = client.catalog(category="stock")
crypto = client.catalog(category="crypto")

# Each entry has symbol, display_name, and category
for s in crypto[:5]:
    print(f"{s['symbol']:12s} {s['display_name']:20s} {s['category']}")

The catalog returns every subscribable instrument. Use it to build symbol pickers, validate user input, or discover what is available.

Available categories

Category	Count	Examples
stock	~3,987	AAPL, NVDA, TSLA, 0005.HK, 7203.T
forex	~62	EUR/USD, GBP/JPY, USD/CHF
crypto	~58	BTC/USD, ETH/USD, SOL/USD
etf	~25	SPY, QQQ, IWM, GLD
commodity	~23	XAU/USD, WTICO/USD, NATGAS/USD
index	~13	US30, NAS100, UK100

Options streaming

Subscribe to entire options chains by underlying. One call gives you every contract (calls + puts, all strikes, all expiries).

from lse import LSE

client = LSE(api_key="your_key")

def on_tick(tick):
    print(f"{tick.symbol}: ${tick.price:.2f}")

client.on("tick", on_tick)
client.subscribe_options(["AAPL", "TSLA"])
client.connect()

To stop receiving a chain:

client.unsubscribe_options(["TSLA"])

Unsubscribe

Remove symbols at runtime without disconnecting:

client.unsubscribe(["BTC/USD"])      # stop one symbol
client.subscribe(["SOL/USD"])        # add another

Disconnect

Stop the stream and exit cleanly. Works from callbacks or another thread:

tick_count = 0

def on_tick(tick):
    global tick_count
    tick_count += 1
    if tick_count >= 100:
        client.disconnect()  # connect()/stream() returns

client.on("tick", on_tick)
client.connect(symbols=["BTC/USD"])
print("Done, collected 100 ticks")

Async version:

await client.disconnect_async()

Requirements

• Python 3.8+
• websockets (installed automatically)

License

MIT