Market Channel (WebSocket)

Overview

Clients subscribe by specifying one or more asset IDs (token IDs). The server can send an initial order book snapshot on subscribe, then pushes incremental price-level changes, trade notifications, top-of-book updates, and lifecycle events to the connection.

Server: wss://api.openfish.me/ws/market

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Subscribe

Direction: Client -> Server

Field	Type	Required	Description
type	string	Yes	"subscribe" or "unsubscribe"
assets_ids	array of strings	Yes	Asset IDs to subscribe/unsubscribe
level	integer	No	Subscription level: 1=trades only, 2=+best bid/ask and price changes (default), 3=allows book initial dump
initial_dump	boolean	No	Send one initial order book snapshot after subscribing when level >= 3 (default: false)

{
  "type": "subscribe",
  "assets_ids": ["52114319501245..."],
  "level": 2,
  "initial_dump": true
}

Complete Example

const ws = new WebSocket("wss://api.openfish.me/ws/market");

ws.addEventListener("open", () => {
  ws.send(JSON.stringify({
    type: "subscribe",
    assets_ids: [
      "52114319501245915516055106046884209969926127482827954674443846427813813222426"
    ],
    level: 2,
    initial_dump: true
  }));
});

ws.addEventListener("message", (event) => {
  if (event.data === "PING") {
    ws.send("PONG");
    return;
  }
  console.log(JSON.parse(event.data));
});

Example server event:

{
  "type": "best_bid_ask",
  "asset_id": "52114319501245915516055106046884209969926127482827954674443846427813813222426",
  "market": "0xbd31dc8a00000000000000000000000000000000000000000000000000000000",
  "best_bid": "0.54",
  "best_ask": "0.56",
  "timestamp": 1770000000000
}

Subscription Levels

Level	Events
1	last_trade_price
2	Level 1 + best_bid_ask, price_change
3	Level 2 + book when initial_dump=true

Lifecycle events (new_market, market_resolved, tick_size_change) are always delivered.

Update Subscription

You can add or remove assets from your subscription without dropping the connection:

{
  "type": "subscribe",
  "assets_ids": ["71321045679252..."]
}

{
  "type": "unsubscribe",
  "assets_ids": ["71321045679252..."]
}

Legacy Query Parameters

For backward compatibility, ?market= and ?asset_id= query parameters are still accepted at connection time.

Heartbeat

The server emits a text "PING" frame every 10 seconds. The client must reply with text "PONG".

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Events

book — Orderbook Snapshot

Sent as a one-time initial snapshot when subscribing with level >= 3 and initial_dump=true. Ongoing order book mutations are sent as price_change and best_bid_ask events.

Field	Type	Description
type	string	"book"
asset_id	string	Asset ID
market	string	Condition ID
bids	array	[{ "price": "0.50", "size": "15" }]
asks	array	[{ "price": "0.52", "size": "25" }]
hash	string	Orderbook content hash
timestamp	string	Unix ms

price_change — Orderbook Delta

Requires level >= 2.

Field	Type	Description
type	string	"price_change"
market	string	Condition ID
asset_id	string	Asset ID
price	string	Affected price level
size	string	New size at this level ("0" = removed)
side	string	"BUY" or "SELL"
hash	string	Book content hash
best_bid	string?	Current best bid (if changed)
best_ask	string?	Current best ask (if changed)
timestamp	integer	Unix timestamp

last_trade_price — Trade Execution

Field	Type	Description
type	string	"last_trade_price"
asset_id	string	Asset ID
market	string	Condition ID
price	string	Execution price
size	string	Trade size
side	string	"BUY" or "SELL" (taker perspective)
timestamp	integer	Unix ms

best_bid_ask — Best Bid/Ask Update

Requires level >= 2.

Field	Type	Description
type	string	"best_bid_ask"
asset_id	string	Asset ID
market	string	Condition ID
best_bid	string?	Best bid price, or null when no bid is available
best_ask	string?	Best ask price, or null when no ask is available
timestamp	integer	Unix ms

tick_size_change — Tick Size Update

Field	Type	Description
type	string	"tick_size_change"
asset_id	string	Asset ID
old_tick_size	string	Previous tick size
new_tick_size	string	New tick size
timestamp	integer	Unix ms

new_market — Market Created

Broadcast to all connected clients regardless of subscription level.

Field	Type	Description
type	string	"new_market"
market	string	Condition ID
question	string	Market question
slug	string	URL-friendly market slug
outcomes	array	Outcome labels (e.g. ["Yes", "No"])
clob_token_ids	array	Token IDs for each outcome
tags	array	Market tags
timestamp	integer	Unix timestamp

market_resolved — Market Resolved

Broadcast to all connected clients regardless of subscription level.

Field	Type	Description
type	string	"market_resolved"
market	string	Condition ID
winning_token_id	string	Winning asset ID
winning_outcome	string	Winning outcome label
assets_ids	array	All asset IDs in the market
tags	array	Market tags
timestamp	integer	Unix timestamp