FIX Administrative Messages


Logon <A>

The Logon <A> message authenticates a user and starts a connection. It must be the first message sent by the client FIX engine.

Upon receipt of a Logon message the OANDA server will authenticate the client using the provided password. A Logon response is returned on successful authentication.

If the server cannot authenticate the logon request, no response is provided – this is done as a precaution against Denial of Service (“DoS”) attacks.

Tag Field Name Required Type / Value Description
standard headers Y MsgType=A
98 EncryptMethod Y char “0” method of encryption
  • “0” - none
  • 108 HeartBtInt Y int heart beat interval in seconds. Minimum value 30, Recommended value 300
    logon password Y see below
    141 ResetSeqNumFlag Y boolean “Y”/“N” indicates both sides should reset sequence numbers
  • “Y” - reset sequence numbers
  • standard trailer Y

    FIX.4.2 connections specify the logon password via

    Tag Field Name Type / Value Description
    95 RawDataLength int number of bytes in RawData field
    96 RawData data unformatted raw data - provide the logon password here

    FIX.4.3+ connections specify the logon password via

    Tag Field Name Type / Value Description
    554 Password string the logon password

    On a successful Logon, the server sends a News <B> message with information on the server connected to.


    News <B>

    The News <B> message provides important information about the current server and connection. This information is often imporant in diagnosing problems.

    Clients are advised to log this information for each connection in their engine logs.

    Tag Field Name Required Type / Value Description
    standard headers Y MsgType=B
    148 Headline Y string “OANDA FIX Server Information”
    33 LinesOfText Y int indicates the number of Text tags following
    –> 58 Text Y string “keyword: value” information
    standard trailer Y

    The Text tag provides information on topics such as:

    • version - the current version of the server

    • notice - important information about the server

    • warning - explicitly flags issues such as compatibility concerns or behavioral changes


    Logout <5>

    The Logout message initiates or confirms the termination of a FIX connection. A connection disconnected without the exchange of Logout message should be interpreted as an abnormal condition (e.g. network failure).

    Tag Field Name Required Type / Value Description
    standard headers Y MsgType=5
    58 Text N string optional explanatory text
    standard trailer Y

    Business Message Reject <j>

    The Business Message Reject rejects application-level messages that satisfy session rules but cannot be rejected by other means.

    Clients are urged to consult the reasons and text provided to assist in problem resolution.

    Tag Field Name Required Type / Value Description
    standard headers Y MsgType=j
    45 RefSeqNum N int MsgSeqNum of the rejected message
    372 RefMsgType Y string MsgType of the rejected message
    379 BusinessRejectRefID N string value of the business-level ID field being referenced
    380 BusinessRejectReason Y int code to identify reason for reject
    58 Text N string explains the rejection
    standard trailer Y

    Please consult the official FIX specifications for BusinessRejectReason valies.