The Open Markets Initiative (Omi) is a market-neutral effort to enhance the stability of electronic financial markets through transparency, modern tooling, and open documentation of the wire protocols that connect them.

24X · A2X · Aquis · Asx · B3 · Bist · Biva · BlueOceanAts · Box · BruceAts · Bse · Cboe · CixAts · Cme · Coinbase · Currenex · ElectronX · Eurex · Euronext · Finra · Fix · Hkex · Ice · Iex · Imperative · Jnx · Jpx · Jse · Koscom · Lseg · Ltse · Memx · Miax · Nasdaq · Nse · NsxAustralia · Nyse · Odx · OtcMarkets · Sgx · Siac · SmallX · Taifex · Tmx · Txse

24XEquities · A2XEquities · AmexEquities · AmexOptions · AquisEquities · ArcaEquities · ArcaOptions · AsxDerivatives · AsxSecurities · B3Derivatives · B3Equities · BidsJapan · BivaEquities · BlueEquities · BorsaIstanbul · BoxOptions · BruceEquities · BseIndia · BxeEquities · BxEquities · ByxEquities · BzxEquities · BzxOptions · C1Options · C2Options · CboeEquities · CboeEurope · CfeFutures · CoinbaseDerivatives · CurrenexForex · CxaEquities · CxeEquities · CxjEquities · CxjSor · Deribit · DxeDerivatives · EdgaEquities · EdgxEquities · EdgxOptions · ElectricDerivatives · EmeraldOptions · FinraOrf · FinraOtc · FixedIncome · FseEquities · GemxOptions · GlobalOtc · HkexDerivatives · HkexSecurities · IceEndex · IceFutures · Idem · IexEquities · IexOptions · IntelligentCross · IseOptions · JnxBonds · JnxEquities · Liffe · LinkAts · LinkEcn · LinkNqb · Lse · LtseEquities · MatchNow · MemxEquities · MemxOptions · MiaxOptions · MoonAts · MrxOptions · Mx · NasdaqCanada · NationalEquities · NeoEquities · NfxFutures · NlxDerivatives · NomOptions · NordicDerivatives · NordicEquities · NseCd · NseCm · NseCom · NseEquities · NseFo · NsmEquities · NtxEquities · NtxOptions · NyseBonds · NyseEquities · NyseOptions · OdxEquities · OdxSecurityToken · OnyxFutures · OseDerivatives · Overnight · PearlEquities · PearlOptions · PhlxOptions · PsxEquities · SapphireOptions · SmallFutures · Sse · SseEquities · Szse · TaifexDerivatives · TexasEquities · Trace · TradeEcho · TseEquities · Tsx · TsxAlpha · Turquoise · TxseEquities

Cqs · Cts · FundNetwork · Index · MdcsRealtime · NordicMarkets · NyseConsolidated · Opra · TitaniumConsolidated · Uqdf · Utdf · Utp

CixAspen · Globex · Itac · Millennium · Nets · Optiq · T7 · TitanDt · TitanOtc

The Directory is the human-readable catalog. The machine-readable specifications live elsewhere and drive the source-generated artifacts:

Generated Definitions

• omi-kaitai-struct-definitions — Kaitai Struct definitions for common exchange binary protocols
• omi-dfdl-definitions — Data Format Description Language schemas for common exchange protocols
• omi-p4-definitions — P4 definitions for common exchange protocols for software and hardware data planes
• omi-fix-dictionaries — FIX protocol dictionaries (QuickFIX-format XML, one per FIX version)
• omi-spicy-definitions — Spicy grammars for common exchange binary protocols, for the Spicy toolchain and Zeek
• omi-lean-definitions — Lean 4 definitions of common exchange binary protocols, with proofs
• omi-xml-specifications — XML specifications for common exchange protocols

Source Generated Outputs

• omi-csharp-protocols — Source generated C# protocol parsers, fixed-layout structs and immutable classes
• omi-rust-protocols — Zero-copy Rust message views, one crate per protocol version
• omi-cpp-protocols — Source generated C++ protocol parsers and utilities
• omi-cpp-formats — Source generated C++ that translates packet captures into formats like JSON and Parquet

Telemetry

• omi-wireshark-lua — Source generated cross platform Wireshark dissectors
• omi-wireshark-c — Source generated Wireshark dissectors in C, built in to Wireshark

Reference Material

• omi-low-latency-reference — Knowledge base for low latency programming
• omi-markets-reference — Knowledge base for market data collection and analysis

Production Sample Data

• omi-data-packets — Example protocol data captures
• omi-data-pcaps — Exchange pcaps for automated testing

A complete list lives in Repositories.

Documentation is collected from publicly available sources — corrections and additions are welcome as issues or pull requests. Read more about the mission in About.

Specifications belong to their respective owners; this directory aggregates pointers and historical context only.