Starkex

Verified Price Feeds

Perfect for StarkEx integrations and applications requiring cryptographic verification of price data

Overview

If you are building on StarkEx or need a robust verification mechanism for price data, this endpoint provides real-time feeds with cryptographic signatures to ensure data integrity and provenance.

Connection

Open WebSocket Connection

Connect to our WebSocket endpoint on your preferred environment:

wscat -c wss://ws.devnet.pragma.build/node/v1/data/subscribe

wscat -c wss://ws.production.pragma.build/node/v1/data/subscribe

Subscribe to Asset Pairs

Send a subscription message to start receiving updates every 500 milliseconds.

Subscription Management

Subscribing to Pairs

{
  "msg_type": "subscribe",
  "pairs": ["BTC/USD", "ETH/USD:MARK"]
}

{
  "msg_type": "subscribe",
  "pairs": ["BTC/USD", "ETH/USD:MARK", "SOL/USD"]
}

The response includes all pairs you are currently subscribed to, including any previous subscriptions not mentioned in your latest request.

Unsubscribing from Pairs

{
  "msg_type": "unsubscribe",
  "pairs": ["BTC/USD"]
}

{
  "msg_type": "unsubscribe",
  "pairs": ["ETH/USD:MARK"]
}

Price Types

Index Price
Mark Price

Median price from spot markets across supported exchanges.

Format Example: BTC/USD

By default, subscriptions are for index prices. Subscribing to a pair without specifying the type will subscribe to the index price.

Median price from perpetual markets across supported exchanges.

Format Example: ETH/USD:MARK

Calculation Method:

For assets quoted in a stablecoin:

Determine the median perp price of the asset quoted in the stablecoin
Determine the median spot price of the stablecoin in USD
Divide the median perp price by the median spot price of the stablecoin in USD

For assets quoted in USD:

Determine the median perp price of the asset quoted in USD

To subscribe to a mark price, append :MARK to the pair name (e.g., ETH/USD:MARK).

Data Format

{
  "global_asset_id": "0x12345",
  "median_price": "10000000000000001",
  "signature": "0x154786876ae878",
  "signed_prices": [
    {
      "oracle_asset_id": "0x12345000000000ABCDEF",
      "oracle_price": "1000000000000000000",
      "signing_key": "0x1234567890ABCDEF",
      "timestamp": "1234567",
      "signature": "0x1234567890ABCDEF"
    },
    {
      "oracle_asset_id": "0x12345000000000FEDCBA",
      "oracle_price": "1000000000000000002",
      "signing_key": "0xFEDCBA0987654321",
      "timestamp": "1234567",
      "signature": "0x1234567890ABCDEF"
    }
  ]
}

Field Reference

Field	Description
`global_asset_id`	Unique identifier for the asset encoded using the pair name
`median_price`	The median price of the asset
`signature`	Signature of the median price by the Pragma oracle
`signed_prices`	Array of the prices used to compute the median price
`oracle_asset_id`	Unique identifier encoded using the pair and publisher names
`oracle_price`	Price provided by the oracle
`signing_key`	Key used by the oracle to sign the price
`timestamp`	Time when the price was recorded
`signature`	Signature of the price by our publisher

All numeric values are returned as strings to preserve precision, especially for assets with very small or very large prices.

Integration Examples

Rust
Python

We’ve created a ready-to-use example with a terminal UI for testing this endpoint:

# Clone the repository
git clone https://github.com/astraly-labs/pragma-node

# Run the example
cargo run --example starkex

Connect to the Pragma websocket endpoint and subscribe to the TIA/USD index price:

import asyncio
import websockets
import json
from websockets.exceptions import ConnectionClosedError

async def connect_and_subscribe():
    uri = "wss://ws.devnet.pragma.build/node/v1/data/subscribe"
    
    try:
        # Connect to the websocket
        async with websockets.connect(uri) as websocket:
            # Subscribe to TIA/USD price
            subscribe_msg = {
                "msg_type": "subscribe", 
                "pairs": ["TIA/USD"]
            }
            
            await websocket.send(json.dumps(subscribe_msg))
            print("Subscribed to TIA/USD")
            
            # Handle incoming messages
            while True:
                message = await websocket.recv()
                data = json.loads(message)
                print(f"Received price update: {data}")
                
    except ConnectionClosedError:
        print("Connection closed unexpectedly")
    except Exception as e:
        print(f"Error: {e}")

# Run the connection
if __name__ == "__main__":
    asyncio.run(connect_and_subscribe())

Comparison with Lightspeed

✓ Includes cryptographic signatures
✓ Verifiable price data
✓ Individual publisher prices
✓ Ideal for StarkEx integration
⚠️ Slightly larger payload size

Lightspeed

✓ Minimal payload size
✓ Optimized for performance
✓ Lower latency
✓ Ideal for trading applications
❌ No verification metadata

Choose Starkex when data provenance and verification are required, and Lightspeed when raw performance is your primary concern.

Overview

Offchain

Onchain

Websocket

Starkex

Verified Price Feeds

Overview

Connection

Subscription Management

Subscribing to Pairs

Unsubscribing from Pairs

Price Types

Data Format

Field Reference

Integration Examples

Comparison with Lightspeed

Starkex

Lightspeed

Verified Price Feeds

​Overview

​Connection

​Subscription Management

​Subscribing to Pairs

​Unsubscribing from Pairs

​Price Types

​Data Format

​Field Reference

​Integration Examples

​Comparison with Lightspeed

Starkex

Lightspeed

Overview

Connection

Subscription Management

Subscribing to Pairs

Unsubscribing from Pairs

Price Types

Data Format

Field Reference

Integration Examples

Comparison with Lightspeed