polyws 0.2.3

Real-time Polymarket CLOB WebSocket streaming for Python

polyws

Real-time Polymarket data streaming for Python. Built for trading bots, data pipelines, and AI agents.

pip install polyws

polyws stream --markets 10

from polyws import WSSubscriptionManager, WebSocketHandlers

stream = WSSubscriptionManager(WebSocketHandlers(
    on_polymarket_price_update=lambda events: [
        print(f"{e.asset_id[:16]}… {float(e.price)*100:.1f}%") for e in events
    ]
))
await stream.add_subscriptions(["<asset-id>"])

---

Why polyws?

Polymarket has two APIs, no official Python streaming library, and a multi-step lookup just to get real-time prices. polyws solves all of that.

The problem

To stream live Polymarket data in Python today, you need to:

1. Query the Gamma API to discover markets and extract clobTokenIds
2. Connect to the CLOB WebSocket with a handshake protocol
3. Manage subscriptions, reconnections, and ping/pong keepalive
4. Maintain an order book cache to compute display prices
5. Implement Polymarket's price calculation logic (midpoint when spread ≤ $0.10, last trade price otherwise)

That's ~500 lines of async boilerplate before you write a single line of business logic.

What polyws gives you

stream = WSSubscriptionManager(handlers)
await stream.add_subscriptions(asset_ids)
# Done. Events flow to your handlers.

• Automatic WebSocket connection, reconnection, and keepalive
• Subscription batching with event-driven flush (no polling)
• Order book cache with sorted bid/ask levels
• Derived display prices matching the Polymarket UI
• CLI for discovery and streaming without writing code
• JSON Lines output for piping into other tools and agents

How it compares

	polyws	poly-websockets (TS)	py-clob-client (official)	polymarket-cli (Rust)
Language	Python	TypeScript	Python	Rust
Real-time streaming	WebSocket	WebSocket	REST only	REST only
Auto-reconnect	Event-driven	Polling (5s interval)	N/A	N/A
Subscription flush	Instant (asyncio.Event)	Polling (100ms interval)	N/A	N/A
Display price logic	Built-in	Built-in	Manual	Manual
Order book cache	bisect.insort	Full re-sort	None	None
CLI	polyws markets/stream	None	None	Full trading CLI
Agent-friendly output	JSON Lines (auto-detect)	None	None	--output json
Trading / orders	No	No	Yes	Yes
Runtime deps	2	5	8+	N/A (binary)
Install	pip install	npm install	pip install	brew install

polyws is not a trading client. It does one thing — real-time data streaming — and does it well. Use it alongside py-clob-client for a complete Python trading stack.

---

CLI

Browse markets

# Top 20 markets by volume
polyws markets

# Search
polyws markets --search "bitcoin" --limit 5

# Sort options: volume (default), liquidity, newest
polyws markets --sort liquidity --limit 10

Stream real-time data

# Stream top 10 markets
polyws stream --markets 10

# Stream specific assets
polyws stream --asset-id 4655345557056451798919...

# Search and stream
polyws stream --search "election"

Output format

polyws auto-detects the output context:

• Terminal (TTY): Human-readable, formatted, colored
• Piped / redirected: JSON Lines — one JSON object per line

# Human output
polyws markets --limit 3

#  99.7%  $58.7M  Will there be no change in Fed rates...  [10255981...]
#   0.2%  $53.5M  Will the Fed decrease rates by 25...     [62938043...]
#   0.1%  $48.3M  Will the Fed decrease rates by 50+...    [46553455...]

# Machine output (piped)
polyws markets --limit 1 | jq .
# {"asset_id": "102559...", "question": "Will there be...", "volume": 58739675, "price": "0.9965"}

This makes polyws natively usable by AI agents — pipe the output, parse the JSON, act on it.

---

Library API

WSSubscriptionManager

from polyws import WSSubscriptionManager, WebSocketHandlers

handlers = WebSocketHandlers(
    on_book=my_book_handler,
    on_price_change=my_change_handler,
    on_last_trade_price=my_trade_handler,
    on_tick_size_change=my_tick_handler,
    on_polymarket_price_update=my_price_handler,  # Derived display price
    on_error=my_error_handler,
    on_ws_open=my_open_handler,
    on_ws_close=my_close_handler,
)

manager = WSSubscriptionManager(handlers, reconnect_interval_s=5.0)

All handlers are async, optional, and receive a list of typed events.

Method	Description
await add_subscriptions(ids)	Subscribe to assets. Connects automatically.
await remove_subscriptions(ids)	Unsubscribe from assets.
get_asset_ids()	List all monitored assets.
get_statistics()	Connection stats (open_websockets, asset_ids, pending_subscribe, pending_unsubscribe).
await clear_state()	Full teardown. Manager is reusable after.

Market Discovery

from polyws import fetch_markets, extract_asset_ids

markets = fetch_markets(limit=10, sort="volume", search="crypto")
assets = extract_asset_ids(markets)  # {asset_id: question, ...}

Event Types

Event	When	Key Fields
BookEvent	Full order book snapshot on subscribe	bids, asks, asset_id
PriceChangeEvent	Order book level added/removed/updated	price_changes[].side, price, size
LastTradePriceEvent	A trade executes	price, side, size
TickSizeChangeEvent	Tick size changes	old_tick_size, new_tick_size
PolymarketPriceUpdateEvent	Derived display price changes	price, midpoint, spread, triggering_event

How display prices work

Polymarket doesn't show raw bid/ask prices. It shows a derived price:

• If bid-ask spread ≤ $0.10 → display the midpoint
• If bid-ask spread > $0.10 → display the last trade price

on_polymarket_price_update fires whenever this derived price changes. This matches what you see on polymarket.com.

---

For AI Agents

polyws is designed as a tool for AI agents that need real-time market intelligence.

As a CLI tool:

# Agent discovers markets about a topic
polyws markets --search "AI" --limit 5 | jq -r '.question'

# Agent monitors prices and acts on thresholds
polyws stream --search "bitcoin" | while read line; do
  price=$(echo "$line" | jq -r 'select(.event=="price_update") | .price')
  # ... agent logic ...
done

As a Python library:

# Agent builds a real-time market monitor
from polyws import WSSubscriptionManager, WebSocketHandlers, fetch_markets, extract_asset_ids

markets = fetch_markets(search="election", limit=20)
assets = extract_asset_ids(markets)

async def on_update(events):
    for e in events:
        if float(e.price) > 0.9:
            await alert(f"High confidence: {assets[e.asset_id]} at {e.price}")

mgr = WSSubscriptionManager(WebSocketHandlers(on_polymarket_price_update=on_update))
await mgr.add_subscriptions(list(assets.keys()))

Why agents prefer polyws over alternatives:

• JSON Lines output — no parsing HTML or tables
• Zero config — no API keys needed for read-only streaming
• Predictable schema — every event is typed and documented
• Instant — WebSocket, not polling REST endpoints
• Composable — pipe into jq, grep, other tools, or import as a library

---

Architecture

polyws/
├── src/polyws/
│   ├── types.py        # Typed dataclasses for all events
│   ├── order_book.py   # Sorted order book cache (bisect.insort)
│   ├── manager.py      # WebSocket lifecycle, reconnect, flush
│   ├── gamma.py        # Gamma API market discovery
│   ├── cli.py          # CLI entry point (argparse)
│   └── logger.py       # stdlib logging
├── tests/              # 53 unit + integration tests
└── examples/           # Ready-to-run scripts

Runtime dependencies: websockets, orjson. That's it.

Python: >= 3.11

---

Development

git clone https://github.com/<org>/polyws.git
cd polyws
python -m venv .venv && source .venv/bin/activate
pip install -e ".[dev]"

# Run tests
pytest

# Run live integration test (requires network)
pytest -m live

---

Inspired by

poly-websockets by Nevua Markets — the TypeScript library that pioneered this approach. polyws is a Python rewrite with performance improvements (event-driven flush, bisect-based order book) and a CLI layer for agents and humans.

License

MIT

Disclaimer

This software is provided "as is", without warranty of any kind. The authors are not responsible for any financial losses, trading decisions, or system failures. Polymarket data is provided by Polymarket's public APIs. Use at your own risk.