📚 API Reference — Overview (MT5)¶

Short, navigable entry point to the MT5 API reference. Use this page to jump to the right place and understand naming rules & conventions.

🗺️ What’s inside¶

Messages — payload structures (requests, replies, snapshots) with field notes.
Enums — all enumerations with human meanings.
Streaming — long‑lived gRPC streams and their chunk types.

Looking for usage? See Cookbook recipes next to this section (e.g. Orders/PlaceMarketOrder, MarketInfo/GetQuote, Streaming/SubscribeQuotes).

Original proto names are scoped for MT5 (e.g., enums prefixed with TMT5_ / BMT5_, messages in mt5_term_api).
In headings we show both: full name and a short alias in parentheses — e.g. OpenedOrderInfo (OpenedOrder).
Inside tables and notes we use short names for easier reading.

Why the MT5 prefixes? They disambiguate MT5 from MT4 artifacts and avoid collisions across modules/languages.

Timestamp ⏰ — UTC time. Log in RFC3339.
Optional fields 🎛 — proto3 optional (or wrappers) indicate presence; omit when not set.
Money & PnL 💵 — in account currency (see AccountSummaryData.account_currency).
Prices & volumes 💹 — validate with SymbolInfoDoubleProperty (SymbolVolumeMin/Max/Step, Point, Digits).

Area	Start here
Connection & Health	`Connect/ConnectEx/Disconnect`, Health.Check → see Messages → Connection & Health
Orders (sync)	`OrderSend{Request,Reply,Data}`, `OrderModify/Close`, and opened/pending order payloads → Messages → Account & Orders
Positions	`PositionInfo`, tickets stream, profits snapshots → Streaming
Market info & quotes	`MrpcMqlTick`, `OnSymbolTick`, `SymbolInfoDouble{Request,Data}` → Messages → Quotes & Market Info
Streaming	Quotes, trade updates, tickets, position PnL, charts/history → Streaming

Optional fields may be omitted by the server when not applicable.
Enums can gain new values — handle unknown values defensively on the client side.
Streaming replies typically use oneof { data = 1, error = 2 }; surface error and transport exceptions to your retry logic.