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✅ Market Book Release

Request: unsubscribe the terminal from Level II (Market Book) updates for a symbol (stop DOM streaming).

Source files:

  • MetaRpcMT5/mt5_account.py — method market_book_release(...)
  • MetaRpcMT5/mt5_term_api_market_info_pb2.py — MarketBookRelease* messages (MarketBookReleaseRequest, MarketBookReleaseReply, MarketBookReleaseData)
  • MetaRpcMT5/mt5_term_api_market_info_pb2_grpc.py — service stub MarketInfoStub

RPC

  • Service: mt5_term_api.MarketInfo
  • Method: MarketBookRelease(MarketBookReleaseRequest) → MarketBookReleaseReply
  • Low-level client: MarketInfoStub.MarketBookRelease(request, metadata, timeout)
  • SDK wrapper: MT5Account.market_book_release(symbol, deadline=None, cancellation_event=None)

🔗 Code Example

# Unsubscribe from DOM (order book) updates for a symbol
res = await acct.market_book_release("EURUSD")
print(res.closed_successfully)  # True if DOM subscription was closed

Method Signature

async def market_book_release(
    self,
    symbol: str,
    deadline: datetime | None = None,
    cancellation_event: asyncio.Event | None = None,
) -> market_info_pb2.MarketBookReleaseData

💬 Plain English

  • What it is. Turns off the order book stream for a symbol.
  • Why you care. Frees terminal/network resources and stops unnecessary updates when a DOM panel is closed.

  • Mind the traps.

  • If there was no active subscription, brokers may return closed_successfully=False.

  • Always pair adds/releases to avoid leaking long‑lived subscriptions in your app.

🔽 Input

Parameter Type Description
symbol str (required) Symbol name (maps to symbol in request).
deadline `datetime None` Absolute per‑call deadline → converted to timeout.
cancellation_event `asyncio.Event None` Cooperative cancel for the retry wrapper.

Request message: MarketBookReleaseRequest { symbol: string }

⬆️ Output

Payload: MarketBookReleaseData

Field Proto Type Description
closed_successfully bool True if the DOM subscription was closed.

Wire reply: MarketBookReleaseReply { data: MarketBookReleaseData, error: Error? } SDK returns reply.data.

🎯 Purpose

  • Disable DOM/Level II streaming when it’s no longer needed.
  • Keep resource usage in check on terminals and networks.
  • Clean up before disconnecting or switching workspaces.

🧩 Notes & Tips

  • Use with market_book_add(symbol) to manage lifecycle of subscriptions.

See also: market_book_add.md, market_book_get.md

Usage Examples

1) Safe cleanup on panel close

# English-only comments per project style
s = "XAUUSD"
res = await acct.market_book_release(s)
if not res.closed_successfully:
    print("No active DOM subscription to close")

2) Add → Get → Release flow

ok = await acct.market_book_add("BTCUSD")
book = await acct.market_book_get("BTCUSD")
_ = await acct.market_book_release("BTCUSD")

3) With deadline & cancel

import asyncio
from datetime import datetime, timedelta, timezone

cancel_event = asyncio.Event()
res = await acct.market_book_release(
    "EURUSD",
    deadline=datetime.now(timezone.utc) + timedelta(seconds=2),
    cancellation_event=cancel_event,
)
print(res.closed_successfully)