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✅ Symbol Exist

Request: check whether a symbol exists on the server (either standard or custom) and whether it’s a custom one.

Source files:

  • MetaRpcMT5/mt5_account.py — method symbol_exist(...)
  • MetaRpcMT5/mt5_term_api_market_info_pb2.py — SymbolExist* messages (SymbolExistRequest, SymbolExistReply, SymbolExistData)
  • MetaRpcMT5/mt5_term_api_market_info_pb2_grpc.py — service stub MarketInfoStub

RPC

  • Service: mt5_term_api.MarketInfo
  • Method: SymbolExist(SymbolExistRequest) → SymbolExistReply
  • Low-level client: MarketInfoStub.SymbolExist(request, metadata, timeout)
  • SDK wrapper: MT5Account.symbol_exist(symbol, deadline=None, cancellation_event=None)

🔗 Code Example

# Check if symbol exists and whether it is custom
from MetaRpcMT5 import mt5_term_api_market_info_pb2 as mi_pb2

info = await acct.symbol_exist("EURUSD")
print(info.exists, info.is_custom)  # e.g., True False

Method Signature

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

💬 Plain English

  • What it is. Returns a tiny struct telling you if the symbol exists and whether it’s a custom symbol.
  • Why you care. Gate user input, avoid 404‑style flows before heavier RPCs (quotes, specs, orders).

  • Mind the traps.

  • Request field is name (string) → pass the exact symbol name.

  • The reply’s .data is unwrapped by the SDK wrapper; you receive SymbolExistData directly.

🔽 Input

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

⬆️ Output

Payload: SymbolExistData

Field Proto Type Description
exists bool True if the symbol exists.
is_custom bool True if the symbol is a custom symbol.

🎯 Purpose

  • Validate user input before deeper calls (quotes/specs/orders).
  • Drive UI hints (e.g., badge custom symbols).
  • Health checks in batch symbol import pipelines.

🧩 Notes & Tips

  • Combine with symbols_total(...) and symbol_name(...) to page through and validate symbol lists.
  • If exists=False, skip any downstream price/spec requests to avoid server noise.

See also: symbols_total.md, symbol_name.md, symbol_select.md

Usage Examples

1) Single symbol — guard before heavy calls

# English-only comments per project style
check = await acct.symbol_exist("BTCUSD")
if not check.exists:
    raise ValueError("Symbol is not available on this server")

2) Batch validate a list

symbols = ["EURUSD", "GBPUSD", "FOOBAR"]
results = {s: (await acct.symbol_exist(s)).exists for s in symbols}
print(results)  # {'EURUSD': True, 'GBPUSD': True, 'FOOBAR': False}

3) UI hint — mark custom symbols

s = "SYNTH_X"
info = await acct.symbol_exist(s)
label = "(custom)" if info.is_custom else ""
print(f"{s} {label}")