What is truefix?

TrueFix is a software library, written in the Rust programming language, that lets computer programs talk to each other using a messaging standard called FIX (Financial Information Exchange). FIX is the protocol that banks, brokers, and trading systems use to send orders and trade information back and forth in real time, so a FIX engine is the piece of software that handles that conversation: opening connections, keeping them alive, resending missed messages, and making sure every message follows the correct format. The project is built to match the features of QuickFIX/J, a well established FIX engine written in Java, but written in Rust instead. That choice matters because Rust catches many memory related bugs before the program even runs, which is valuable in financial software where mistakes can be expensive. TrueFix supports both roles in a FIX conversation: it can be the side that starts a connection, called an initiator, and the side that accepts one, called an acceptor, including handling many client connections at once. It also supports the newer secure connection standards, TLS and mTLS, works with several ways of saving message history such as in memory, in files, or in databases like SQL, MSSQL, or MongoDB, and runs on Tokio, a popular Rust toolkit for handling many things happening at once. To use it, a developer adds TrueFix to a Rust project, writes a small configuration file describing the connection, and implements a few callback functions that TrueFix calls when events happen, such as a successful login. The project also ships runnable example programs and standalone connectors for a few outside trading platforms including Futu, Interactive Brokers, OKX, and IG. This is developer infrastructure for people building or operating trading systems, not an end user application. It comes with a large automated test suite, 483 passing test scenarios, that the maintainers use as a gate before releasing new versions, and it is available under either the Apache 2.0 or MIT open source license, so it can be used freely, including commercially.