Pyth Value Feed

Real-time Pyth price and Treasury yield updates for configured underlying tickers. Requires authentication.

Access and pricing

The Pyth data feed costs $1,000/month, with the first seven days free. Subscribe to the Pyth data feed.

Connect using an authenticated Kalshi WebSocket session. See Quick Start: WebSockets for API key authentication and request signing.

Underlying tickers

The reference table below lists supported underlyings: spot metals, metal and commodity indices, an equity index, FX pairs, and Treasury yields. Index descriptions note Pyth’s publishing schedule (24/7, 24/5, or 23/5); spot metals, FX pairs, and Treasury yields follow their market sessions.

Pass the exact Pyth symbol in underlying_tickers. The numeric Pyth feed IDs are reference information and are not subscription parameters for this channel. Kalshi market tickers are not Pyth underlying tickers.

Use underlying_list to discover recently streamed tickers on your connection. Availability can change, including as futures contracts expire; the table does not guarantee that every feed is streaming in every environment.

Treasury yields use the exact symbols above, without a /USD suffix. They are included in ["all"] subscriptions and can also be requested individually, for example with underlying_tickers: ["InterestRate.US2Y"]. These are the yield feeds behind the KX{2,5,10,30}YRRATE15M and KX{2,5,10,30}YRRATEH markets; /USD symbols identify separate bond-price feeds.

Requirements

• Authentication required
• Seed underlying_tickers in the initial subscribe, or add them later
• Use underlying_tickers: ["all"] to receive every available underlying
• Supports update_subscription with subscribe_underlyings, unsubscribe_underlyings, and underlying_list actions
• Duplicate and out-of-order source timestamps are ignored independently per underlying ticker

Subscription workflow

Subscribe to pyth_value with the underlying tickers you want to receive. For example, request gold, oil, and natural gas prices:

{
  "id": 1,
  "cmd": "subscribe",
  "params": {
    "channels": ["pyth_value"],
    "underlying_tickers": [
      "Metal.XAU/USD",
      "Commodities.Index.PYTHOIL/USD",
      "Commodities.Index.NATGAS/USD"
    ]
  }
}

A successful subscribe returns a subscribed response with the assigned sid. Use that subscription ID in subsequent commands; replace sid: 1 in the examples below with the returned ID.

You can also omit underlying_tickers to create an empty subscription, discover tickers, and add them later. An empty subscription sends no price updates until you add tickers or switch to ["all"].

Discover recently streamed tickers

{
  "id": 2,
  "cmd": "update_subscription",
  "params": {
    "sid": 1,
    "action": "underlying_list"
  }
}

Read msg.underlying_tickers in the pyth_value_underlying_list response. This lists tickers observed on the stream within the last two hours without changing your subscription. It is not a complete catalog: inactive feeds can be absent. A successful subscribe response alone does not confirm that a requested ticker is streaming.

Add or remove tickers

Add platinum to the existing subscription:

{
  "id": 3,
  "cmd": "update_subscription",
  "params": {
    "sid": 1,
    "action": "subscribe_underlyings",
    "underlying_tickers": ["Metal.XPT/USD"]
  }
}

Remove platinum from the subscription:

{
  "id": 4,
  "cmd": "update_subscription",
  "params": {
    "sid": 1,
    "action": "unsubscribe_underlyings",
    "underlying_tickers": ["Metal.XPT/USD"]
  }
}

Receive all available underlyings

Set underlying_tickers to ["all"] in the initial subscribe, or enable it on an existing subscription:

{
  "id": 5,
  "cmd": "update_subscription",
  "params": {
    "sid": 1,
    "action": "subscribe_underlyings",
    "underlying_tickers": ["all"]
  }
}

While all-mode is enabled, removing an individual ticker does not exclude it. Send unsubscribe_underlyings with ["all"] to disable all-mode; any explicitly subscribed tickers remain selected.

Integration notes

• sid identifies the subscription stream; use it for update_subscription and unsubscribe.
• Missing or empty underlying_tickers for subscribe_underlyings or unsubscribe_underlyings returns an error with code: 28 (“Underlying tickers required”).
• value_usd is formatted to eight decimal places. The field name is retained for compatibility: for Treasury yield symbols it contains the yield in percent, so "4.25000000" means 4.25%, not a dollar price or a decimal fraction. Other symbols retain their quoted price units.
• source_ts_ms is the source timestamp in Unix milliseconds; received_at is when Kalshi received the update, also in Unix milliseconds.