MQL5 Helper EA

Mt5BridgeHelper.mq5 is an MQL5 Expert Advisor that listens for async commands sent by the Python mt5bridge-ccxt package and executes them on the MT5 side.

Why is this needed?

MT5Bridge's HTTP API does not expose a synchronous cancel/modify/close endpoint. To still support these operations, the wrapper writes GlobalVariable commands on the MT5 side that this helper EA reads and acts on.

Installation

Copy Mt5BridgeHelper.mq5 to your MT5 MQL5/Experts/ directory.
In MetaEditor, compile the file (F7).
Open any chart in MT5 (e.g. EURUSD M1).
Drag Mt5BridgeHelper from the Navigator onto the chart.
In the Inputs dialog, leave defaults (1s polling, logging on).
Make sure "Allow Algo Trading" is enabled in the MT5 toolbar.
Click OK. You should see [Mt5BridgeHelper] Started in the Experts log.

The helper EA runs on a single chart and handles commands for all symbols on the account.

Supported Commands

GlobalVariable name	Action
`MT5BRIDGE_CMD_CANCEL_{id}`	Calls `OrderDelete(id)` for a pending order
`MT5BRIDGE_CMD_MODIFY_{id}`	Modify SL/TP/price (full payload in v0.2)
`MT5BRIDGE_CMD_CLOSE_{id}`	Calls `PositionClose(id)` for an open position

Usage from Python

import mt5bridge_ccxt
exchange = mt5bridge_ccxt.mt5bridge({...})

# Send async cancel command
result = exchange.cancel_order("12345")
print(result)
# {'info': {'method': 'gvar_signal', 'command_key': 'MT5BRIDGE_CMD_CANCEL_12345', 'ticket': 12345},
#  'id': '12345', 'status': 'canceling'}

# Send async close command for a position
result = exchange.mql5.send_close_command(98765, volume=0.01)

Limitations

Async: commands take up to 1s to be picked up by the EA (default poll interval).
No confirmation: the wrapper returns "canceling" immediately; you must poll fetch_open_orders / fetch_positions to confirm the operation succeeded.
MT5 restart: in-flight commands stored only as GlobalVariables will be lost if MT5 restarts before the EA processes them.