mkfix

A FIX protocol testing engine for capital markets connectivity, built on mkio and mkui.

Features

• Session Management -- Configure and run FIX sessions as initiator or acceptor. Multiple sessions on the same port with different CompIDs.
• Raw Message Viewer -- Live virtualized table of FIX messages in tag=value format, streaming live by default, with time-based paging, per-column filters, sorting, and clipboard copy.
• Message Detail -- Field-by-field breakdown of the message selected in the Raw Message viewer, with field names and enum translations.
• Client Order & Trade Blotters -- Live order state machine driven by ExecutionReports; fill and partial fill records. Send NewOrderSingle from the blotter's New dialog; Cancel and Cancel/Replace working orders directly from the blotter.
• Market Order & Trade Blotters -- The other side of the same flow: received orders can be accepted, rejected, and filled from the Market Orders blotter; sent trades can be corrected and busted from the Market Trades blotter (FIX 4.2 ExecTransType Correct/Cancel with ExecRefID).
• Message Replay -- Load production FIX logs and replay them into a test session with speed control, message filtering, and pause/resume.
• IOI & Allocation Viewers -- Indications of Interest and Allocation message tracking.
• Session Protocol -- Logon, Logout, Heartbeat, TestRequest, ResendRequest, SequenceReset, GapFill, PossDupFlag handling, and heartbeat timeout detection.

Installation

pip install mkfix

Or from source:

git clone https://github.com/markuskimius/mkfix.git
cd mkfix
pip install -e .

Usage

mkfix                        # start with defaults (port 8080, mkfix.db)
mkfix -p 9090                # override port
mkfix -d mytest              # use mytest.db
mkfix -d :memory:            # in-memory database
mkfix myconfig.toml          # custom config file

Then open http://localhost:8080 in your browser.

Quick Start

1. Create two sessions in the Session Manager -- one initiator pointing at the other as acceptor on the same port.
2. Start both sessions -- Logon and Heartbeat messages will stream in the Raw Messages pane.
3. Send an order with the New button on the Client Orders blotter -- see it in Raw Messages and the blotter itself; click any message row to break it out field by field in Message Detail. On the acceptor side it appears in Market Orders, where it can be accepted, rejected, or filled; fills land in Market Trades, where they can be corrected or busted.
4. Replay a log from Tools > Replay Control -- load a production FIX log and replay it into a test session.

Configuration

mkfix uses a TOML config file (mkfix.toml). The built-in default is used when no config is specified. Key settings:

port = 8080
host = "0.0.0.0"
db_path = "mkfix.db"

Tables, services, and static routes are also configured in the TOML file. See the built-in mkfix.toml for the full schema.

Dependencies

• mkio >= 0.1.65 -- async microservice framework (aiohttp + aiosqlite)
• mkui >= 0.1.53 -- Web Components UI framework

License

GPL-2.0