# Buy a Liquid Event Use this script to buy into a liquid event at a target price. ### What this script does * finds the most liquid event * watches the order book in real time * places a market buy when the YES price reaches `$0.40` * spends `10%` of available USDC balance Start with [Setup & Helpers](/api/rest-api/python-examples/setup-and-helpers.md) if you still need the shared prerequisites. {% code title="buy\_liquid\_event.py" %} ```python #!/usr/bin/env python3 """Buy YES token at $0.40 on the most liquid event, spending 10% of USDC balance.""" import asyncio, json, requests, websockets import hmac, hashlib, base64, time API_KEY = "op_k_your_api_key" API_SECRET = "your_api_secret" USDC_ID = "078dcd98-928d-479f-8110-ff6d27e44de2" TARGET_PRICE = 0.40 BALANCE_FRACTION = 0.10 SERVICE_MAP = { "/api/events": "https://event-service.outpoll.com", "/api/user-balances": "https://wallet-mutator-view.outpoll.com", "/api/history": "https://history-service.outpoll.com", "/orders": "https://order-service.outpoll.com", } class OutpollClient: def __init__(self, api_key, api_secret): self.api_key = api_key self.api_secret = api_secret def _host(self, path): for prefix, host in SERVICE_MAP.items(): if path.startswith(prefix): return host return "https://event-service.outpoll.com" def _sign(self, method, path, body=""): timestamp = str(int(time.time())) message = timestamp + method + path + body padded = self.api_secret + "=" * (4 - len(self.api_secret) % 4) if len(self.api_secret) % 4 else self.api_secret secret_bytes = base64.urlsafe_b64decode(padded) signature = base64.urlsafe_b64encode( hmac.new(secret_bytes, message.encode(), hashlib.sha256).digest() ).decode().rstrip("=") return { "OUTPOLL-API-KEY": self.api_key, "OUTPOLL-API-SIGNATURE": signature, "OUTPOLL-API-TIMESTAMP": timestamp, "Content-Type": "application/json", } def post(self, path, data=None): body = json.dumps(data) if data else "" headers = self._sign("POST", path, body) return requests.post(self._host(path) + path, headers=headers, data=body) def ws_auth_msg(path): timestamp = str(int(time.time())) message = timestamp + "GET" + path s = API_SECRET s += "=" * (4 - len(s) % 4) if len(s) % 4 else "" secret_bytes = base64.urlsafe_b64decode(s) signature = base64.urlsafe_b64encode( hmac.new(secret_bytes, message.encode(), hashlib.sha256).digest() ).decode().rstrip("=") return {"t": "AUTH", "d": {"apiKey": API_KEY, "signature": signature, "timestamp": timestamp}} # Step 1 — Find the most liquid event print("Searching for most liquid event...") resp = requests.post( "https://event-service.outpoll.com/api/events/search", params={"page": 0, "size": 1}, json={"sb": "LIQUIDITY", "sd": "DESC", "l": "en"}, ) event = resp.json()["content"][0] market = event["ma"][0] yes_runner = next(r for r in market["r"] if r["ip"]) EVENT_ID = event["i"] OUTCOME_ID = market["i"] RUNNER_ID = yes_runner["i"] print(f"Event: {event['ti']}") print(f"YES price: ${yes_runner['p']:.2f}") print(f"Target: ${TARGET_PRICE:.2f}") async def run(): client = OutpollClient(API_KEY, API_SECRET) # Step 2 — Get USDC balance via Balance WebSocket print("\nFetching USDC balance...") usdc_balance = 0.0 async with websockets.connect("wss://wallet-mutator-view.outpoll.com/balance/ws") as ws: await ws.send(json.dumps(ws_auth_msg("/balance/ws"))) msg = json.loads(await asyncio.wait_for(ws.recv(), timeout=10)) if msg.get("t") == "success": for b in msg["d"]["l"]: if b["i"] == USDC_ID: usdc_balance = b["f"] break spend = round(usdc_balance * BALANCE_FRACTION, 2) print(f"USDC free: ${usdc_balance:.2f}") print(f"Will spend: ${spend:.2f} (10%)") if spend < 1: print("Insufficient balance. Exiting.") return # Step 3 — Monitor order book, wait for YES ≤ $0.40 print(f"\nWatching order book for YES ≤ ${TARGET_PRICE}...") async with websockets.connect("wss://order-book.outpoll.com/event/ws") as ws: await ws.send(json.dumps({"t": "SUBSCRIBE", "e": EVENT_ID})) async for raw in ws: data = json.loads(raw) if data["t"] not in ("PRICES_DATA", "PRICES_DATA_DELTA"): continue for p in data["d"]: if p["o"] != RUNNER_ID: continue chance = p["c"] print(f" YES: ${chance:.4f} (bid={p['b']:.4f}, ask={p['a']:.4f})", end="\r") if chance <= TARGET_PRICE: # Step 4 — Market buy print(f"\n\nPrice hit ${chance:.4f} ≤ ${TARGET_PRICE}! Buying...") order = client.post("/orders/market", { "e": EVENT_ID, "o": OUTCOME_ID, "ba": RUNNER_ID, "qa": USDC_ID, "s": "BUY", "am": spend, }) print(f"Order placed: {order.json()}") return asyncio.run(run()) ``` {% endcode %} ### Related pages * [Order Book](/api/rest-api/websockets/order-book.md) * [Balances](/api/rest-api/private-endpoints/balances.md) * [Place Market Order](/api/rest-api/private-endpoints/orders/place-market-order.md) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.outpoll.com/api/rest-api/python-examples/buy-a-liquid-event.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.