developers:fixapi:logon

LOGON [35=A]

The Logon message initiates a FIX session with authentication and session configuration.

Required credentials:

Tag Field Description
49 SenderCompID T4 Application Name (use “T4Example” for simulator)
56 TargetCompID T4 Firm Name
553 UserName T4 User
554 Password T4 Password
91 SecureData License Code (use 112A04B0-5AAF-42F4-994E-FA7CB959C60B for T4Example)
90 SecureDataLen Length of license code
Value Function
d Disable AutoPortfolio refresh
BB Disable auto account subscription
c Enable security definitions
8 Enable pending execution reports
D Enable decimal pricing (required for 8-decimal instruments)
BA Drop copy mode (reporting only)
BG Dynamic account notifications
CB Disable user notifications
V Chart data requests
UCG Multi-Trader mode

Message Direction: Client → T4

Tag Field Name Type Req'd Description
Message Header Y MsgType = A
91 SecureData String Y Application license code
90 SecureDataLen Int Y License code length
98 EncryptMethod Int Y Always 0 (none)
108 HeartBtInt Int Y Heartbeat interval (30 seconds)
553 UserName String Y T4 User
554 Password String Y T4 Password
925 NewPassword String O Change password
1408 DefaultCstmApplVerID String O API version
1407 DefaultApplExtID String O Application fingerprint
384 NoMsgTypes Int O Number of RefMsgTypes
→372 RefMsgType String C Session properties (see table)
Message Trailer Y

Logon Request:

8=FIX.4.2|9=200|35=A|49=T4Example|56=T4|52=20130607-14:47:22.872|
91=112A04B0-5AAF-42F4-994E-FA7CB959C60B|90=36|98=0|108=30|
553=username|554=password|384=2|372=d|372=D|10=123|

Logon Response:

8=FIX.4.2|9=150|35=A|49=T4|56=T4Example|50=T4FIX|52=20130607-14:47:24.085|
98=0|108=30|553=username|554=***|1408=4.1.1.1|10=234|
  • Session must start with sequence number 1
  • Dropped connections require new session (sequence 1)
  • Default behavior: AutoPortfolio refresh and account subscription enabled
  • User must have assigned accounts and exchanges before API usage
  • Failed authentication returns Logout with error description
  • developers/fixapi/logon.txt
  • Last modified: 2025/09/12 02:20
  • by chad