MIAXdx (LedgerX) Market Data Feed

asyncapi: 3.0.0
info:
  title: MIAXdx (LedgerX) Market Data Feed
  version: '1.0.0'
  description: |
    WebSocket market data and account feed for MIAX Derivatives Exchange (LedgerX).

    NOT A PROVIDER-PUBLISHED SPEC. MIAXdx publishes no AsyncAPI document. This description was
    derived by API Evangelist from the provider's own published message field tables on the
    Connecting, Market Data Feed, Top of Book Feed, Server Heartbeats and Monotonic Clock
    reference pages. Every field and description below is taken from those pages; nothing was
    invented. Fields the provider did not document are absent rather than guessed.

    Provenance: generated 2026-07-19, method derived, source
    https://web.archive.org/web/2024/https://docs.ledgerx.com/reference/market-data-feed
  contact:
    name: MIAXdx Customer Support
    url: https://support.miaxdx.com/hc/en-us
  externalDocs:
    url: https://docs.miaxdx.com/reference/connecting
servers:
  production:
    host: api.ledgerx.com
    pathname: /ws
    protocol: wss
    description: >-
      Upgrade an HTTPS connection to WebSockets. Pass ?token=YOUR_API_KEY for authenticated
      messages such as account balance and position changes. Pass ?presence=true to indicate
      availability for chat messages and negotiated trades. Rate limited to 10 requests per minute.
      The server sends a ping every 8 seconds and severs the connection if no pong is received
      within 32 seconds (RFC 6455 control frames).
    security:
    - $ref: '#/components/securitySchemes/apiKeyToken'
channels:
  feed:
    address: /ws
    title: Market data and account feed
    description: >-
      Single multiplexed WebSocket channel. Message type is carried in the type field. Since the
      feed contains all action reports, a client receives both its own initial action reports and
      subsequent fills against its resting limit orders.
    messages:
      actionReport:
        $ref: '#/components/messages/actionReport'
      bookTop:
        $ref: '#/components/messages/bookTop'
      heartbeat:
        $ref: '#/components/messages/heartbeat'
operations:
  receiveFeed:
    action: receive
    channel:
      $ref: '#/channels/feed'
    summary: Receive streamed orders, trades, cancels, top-of-book changes and exchange heartbeats.
    messages:
    - $ref: '#/channels/feed/messages/actionReport'
    - $ref: '#/channels/feed/messages/bookTop'
    - $ref: '#/channels/feed/messages/heartbeat'
components:
  securitySchemes:
    apiKeyToken:
      type: httpApiKey
      name: token
      in: query
      description: >-
        JWT API key passed as the token query parameter. On an authenticated connection,
        action_report messages describing the account holder's own orders carry the CID and MPID
        fields; those fields are absent on other participants' orders and on unauthenticated
        connections.
  messages:
    actionReport:
      name: action_report
      title: Action Report
      summary: >-
        Describes activity on the market, such as fills, cancels and limit order insertions onto
        the Central Limit Order Book. Status codes are catalogued in errors/ledgerx-error-codes.yml.
      payload:
        $ref: '#/components/schemas/ActionReport'
    bookTop:
      name: book_top
      title: Top of Book
      summary: >-
        Dispatched for a contract every time the best price on that contract changes.
      payload:
        $ref: '#/components/schemas/BookTop'
    heartbeat:
      name: heartbeat
      title: Server Heartbeat
      summary: >-
        Sent roughly once per second. Indicates the exchange is running and, if any contracts are
        active, whether those markets are open for trading.
      payload:
        $ref: '#/components/schemas/Heartbeat'
  schemas:
    ActionReport:
      type: object
      properties:
        type:
          type: string
          const: action_report
        contract_id:
          type: integer
          description: The ID of the contract this order is for
        open_interest:
          type: integer
          description: The open interest on the contract this order is for
        mid:
          type: string
          description: The order message ID
        order_type:
          type: string
          description: customer_limit_order
        price:
          type: integer
          description: The current price of this order
        size:
          type: integer
          description: The current size of this order
        inserted_price:
          type: integer
          description: The inserted price of this order
        inserted_size:
          type: integer
          description: The inserted size of this order
        filled_price:
          type: integer
          description: The filled price of this order
        filled_size:
          type: integer
          description: The filled size of this order
        original_price:
          type: integer
          description: The original price of a canceled or filled order
        original_size:
          type: integer
          description: The original size of a canceled or filled order
        vwap:
          type: integer
          description: Volume-weighted average price this order has been filled at
        is_ask:
          type: boolean
          description: Whether this order is an ask (true) or a bid (false)
        clock:
          type: integer
          description: >-
            Per-contract monotonically incrementing counter. Apply an action report only when its
            clock equals current_clock + 1; handle gaps by refetching book state.
        cid:
          type: integer
          description: >-
            Customer ID. Present only on the connected trader's organization's orders over an
            authenticated connection.
        mpid:
          type: string
          description: >-
            Market Participant ID. Action reports without mpid set can safely be ignored when
            tracking your own fills.
    BookTop:
      type: object
      properties:
        type:
          type: string
          const: book_top
        contract_id:
          type: integer
          description: The contract ID this message describes
        ask:
          type: integer
          description: The lowest ask for this contract
        ask_size:
          type: integer
          description: The size of the top ask
        bid:
          type: integer
          description: The highest bid for this contract
        bid_size:
          type: integer
          description: The size of the top bid
        clock:
          type: integer
          description: >-
            The current clock for the entire contract. This is not the original clock of this
            order's insert.
    Heartbeat:
      type: object
      properties:
        type:
          type: string
          const: heartbeat
          description: websocket message type
        timestamp:
          type: integer
          description: nanoseconds since Unix epoch UTC
        ticks:
          type: integer
          description: monotonic clock value
        run_id:
          type: integer
          description: >-
            Time at which the exchange was last hard-restarted, in nanoseconds since Unix epoch
            UTC. A change means all volatile open orders were canceled unconditionally.
        interval_ms:
          type: integer
          description: The server heartbeat interval, in milliseconds
        exchange_next_open_ts:
          type: integer
          description: The next timestamp upon which the exchange will open
        exchange_next_close_ts:
          type: integer
          description: The next timestamp upon which the exchange will close
        is_exchange_open:
          type: boolean
          description: Tells whether the exchange is accepting orders and executing trades
      examples:
      - type: heartbeat
        is_exchange_open: true
        interval_ms: 1000
        run_id: 1705674614858326580
        ticks: 34474404
        exchange_next_open_ts: 1706020200000000000
        exchange_next_close_ts: 1705957200000000000
        timestamp: 1705939663000000000