allMids

Stream mid prices for every market, updated every block. Requires add-on permission.

⚠️ This is an add-on endpoint - access has to be purchased separately.

Stream mid prices ((best_bid + best_ask) / 2) for every market in a single subscription, updated every block (~70ms). Hyperliquid-compatible: clients that read data.mids work unchanged.

To minimize bandwidth, allMids sends only the coins whose mid changed on each block (a delta). The first message after subscribing is a full snapshot (isSnapshot: true); after that you receive changed-only deltas. The per-subscription seq is gap-free, so a seq jump signals a dropped message — reconnect to receive a fresh snapshot and resync. Apply each message by merging its mids into your local map.

For top-of-book bid/ask sizes use bbo; for full depth use l2Book; for mark/oracle/open-interest use allActiveAssetCtx.

Subscribe

{
    "method": "subscribe",
    "subscription": {
        "type": "allMids"
    }
}

With filters:

{
    "method": "subscribe",
    "subscription": {
        "type": "allMids",
        "dex": "xyz",
        "marketTypes": ["perp", "spot", "outcome"]
    }
}

Parameters:

Parameter	Type	Required	Description
dex	string	No	Filter by DEX prefix. "main" returns native coins (BTC, ETH, …); other values (e.g. "xyz") return only coins with that prefix (xyz:SP500). Omit for all DEXes.
marketTypes	string[]	No	Restrict to specific market types. Each entry is "perp", "spot", "outcome", or the wildcard "*" (alone) for "every type the server currently tracks". Omitting the field defaults to ["perp"] — spot and outcome markets do not appear unless you opt in. The default never grows; pass ["*"] to auto-opt-in to future types.

A second allMids subscribe with a different filter replaces the previous one rather than coexisting with it.

Unsubscribe

{
    "method": "unsubscribe",
    "subscription": {
        "type": "allMids"
    }
}

Update data format

{
    "channel": "allMids",
    "seq": 7,
    "cursor": "5123456:1704067200000",
    "data": {
        "mids": {
            "BTC": "70325.5",
            "ETH": "3228.25"
        },
        "time": 1704067200000,
        "blockHeight": 5123456,
        "isSnapshot": false
    }
}

When isSnapshot is true, mids is the complete set for your filter (sent once on subscribe). When false, mids contains only the coins that changed in that block. In both cases, merge mids into your local map.

Field reference

Field	Type	Description
mids	object	Map of coin symbol → mid price (decimal string)
time	number	Block timestamp (milliseconds since epoch)
blockHeight	number	Block height this update was computed at
isSnapshot	boolean	true = full map (sent once on subscribe); false = changed-only delta

Examples

JavaScript

const WebSocket = require('ws');

const ws = new WebSocket(`wss://api.hydromancer.xyz/ws?token=${process.env.HYDROMANCER_API_KEY}`);
const mids = {}; // local map, merged on every message

ws.on('message', (data) => {
    const msg = JSON.parse(data);

    if (msg.type === 'connected') {
        ws.send(JSON.stringify({
            method: 'subscribe',
            subscription: { type: 'allMids' }
        }));
    } else if (msg.type === 'ping') {
        ws.send(JSON.stringify({ type: 'pong' }));
    } else if (msg.channel === 'allMids') {
        Object.assign(mids, msg.data.mids); // merge delta or snapshot
        console.log(`BTC mid: ${mids['BTC']} @ block ${msg.data.blockHeight}`);
    }
});

Python

Common errors

1. Rate limit exceeded - allMids requires add-on permission — your API key is missing the allMids add-on.

2. Connection timeout — respond to ping messages with pong.

3. Invalid API key