Concepts

These pages explain how Open Meridian is put together and why. They are not step-by-step instructions: for those, start with installing a deployment and your first plugin. Read the concepts when you want to know what a step is doing, what a setting protects, or where a piece of data lives.

Page	What it explains
Architecture	The two halves of Open Meridian — the platform and your deployment — what runs in each, and what crosses between them
Plan your deployment	A firm's profile answered in three layers — core as its books and records, plugins by role, configuration — with what exists, what is planned and what to build, worked for three firms
Service levels	Desktop, single node, multi-node and multi-zone: what each rides out, the chart values that reach it, and the hot layer
Projects and deployments	How a deployment is registered on the platform, how it proves who it is, and the one-time codes it is set up with
Plugins, roles and grants	What a plugin is, what it may do on the bus, how that is decided, and how people reach its pages, by Manage, Open and View
Registries	Where a plugin comes from: a deployment's own Local registry and the platform's Community one, who publishes, how the platform builds and checks each version, and what a deployment verifies before it installs one
Roles	Each of the fifteen roles, reference and pricing among them: its persona, duties, what it leaves to another role and what it holds; the principles a plugin must fit, and how an idea maps to the least roles
Access	How people sign in to a deployment, and how the dashboard decides what each of them may reach, per role of a plugin: the access levels and account access, and a person's own settings
Accounts	The firm's accounts, how an account at a broker or custodian is tied to one, the accounts a plugin may link to and each account's attributes in the book
The book of record	The firm's own record of what each account holds, how it differs from the street and the edge, and how operations opens and reconciles it
The custodian's activity	What a custody plugin reports of what happened on an account, and how operations explains a break and proposes its entry from it
The archive	An edge plugin's raw records: each kind's window, archived, kept or deleted past it, the deployment admin's archive, bound and holds, restore, and the record every move leaves.
Instruments	Instrument identity, the security master, and the copy a deployment keeps of it; each identifier's window, binary event contracts, and an ID never reused
Listed options and futures	Listed options' and futures' templates and series keys, a chain read without minting, a series minted when wanted under the series request rule, lifecycle events in the book with the broker's report as the record, daily settlement variation, and package orders
Companies and corporate actions	The company kind, ENT- records resolved by CIK or LEI with the platform asked on a miss, a subject's role on a row, declared cash dividends, and the filings slice core serves later
One ID per instrument	Every instrument named by the platform's INS- ID, minted from the platform's own source; local LCL- records until it answers, never priced; why a thin statement line stays unrecognised; the licence list, usage reporting and orders on local records
Event groups	A venue's event contracts grouped by event in the instrument master: mutually exclusive and exhaustive as stated or not stated, every version kept, reported by a data plugin and minted by the platform
The lake	Where a deployment keeps what its data sources say, prices and bars, by dataset: versions, reads as of a recorded time, the source priority, wants, kept or served; trades and quotes, streamed, caught up after a watermark; event contracts' outcomes; and who reads them
Rates	The lake's rates: fixings, averages, index levels and curves' points, each a value with its unit, convention and tenor, about a referential record that is never held; read point in time and by publication time
Data age and liveness	A dataset's liveness, declared delay and staleness threshold, the trading sessions staleness counts in, the ems's stale-reference hold or warning and what the deployment permits, and the latency plugins and core report: breaches, notices, the Summary's line and the Age tab
Licences and entitlements	The terms a dataset is kept on, the one-person warning, which plugins may read it and which fields, and who changed what
The analytics component	Figures over the book and the lake for the plugins that ask: jobs for a moment or a business date, in a reporting currency; the measures, realized P&L among them, and the pricing models; the options measures over a chain, IV, greeks, the surface, the grid and positioning, priced at Treasury's curve; fiat legs inverted and crossed through the deployment's pivots; the pricing role's seam, provenance and the answer hash, what is not evaluated and why, and its current limits
Scenarios	The common scenario format: shocks to spot, a surface, a rate or time, each with its form and unit; scenario sets as axes; saved by a signal plugin and named by a job
Execution costs	TCA: each fill's cost in basis points against the mid at four moments, from the sources a job chooses, recorded as the lake's account-scoped rows; what is not measured, and why
Money and instruments	Why every amount names a cash instrument, fiat and tokens alike, and a fiat code resolved by core
Venues	The platform's venue master: a venue ID, its MIC and vendors' codes, pulled one at a time, and where a deployment names a venue
Dates and time	Moments and plain dates, a daily price keyed by its business date, a dataset's day, and a date checked at both ends
Tickets and the inbox	How a problem someone sees reaches the people who can act on it: who sees a ticket, advice that changes nothing, the acts only a person takes, and the inbox
Prepared changes	An agent or a person prepares a change and a person makes it; what agents may do with each act, set by the deployment admin and a plugin's admin; the second pair of eyes; lapse
Service accounts	A user of the deployment that is not a person, which a plugin's autonomous work runs as: its owner, prepare only or act, granted per role, what binds it and what is recorded
The order lifecycle	How an order reaches a venue through the book: who does what by role, the states and the transition table, child orders, the release gate and waiting for compliance, connectivity plugins linked to an ems, fills moving positions, venue-originated fills, and trading instructions
Placement types and RFQ quotes	How a placement is executed, DMA, algo, care, RFQ or manual; a manual placement's evidence; the dealers' quotes on the buy side's RFQ placement and the pick
FX netting	Opposite FX orders on one pair and one value date netted into one order, the offset crossed internally at a recorded rate, and booked as a block
The agents' guard	Agents place orders on demo connections only: what the book refuses and records, how a connection's environment is decided from its setting and its session, and the Demo and Live badges
Booking	An order's executions booked to its accounts, the block, the error account, the hand-off, corrections, sleeves, give-ups and alerts, and which currency has lots
Settlement calendars	Business-day calendars and date rules the platform keeps and a deployment pulls; a settlement, spot or tenor date worked out one way in core, with its basis; coverage, and the Calendars tab
Development deployments	A deployment installed for writing plugins, and why a firm's own deployment is never one

What Open Meridian does today

A deployment signs people in, administers who may reach what, catalogues and runs plugins, resolves instruments, records what custodians say is held and what happened on each account, keeps the firm's own book of record, reconciled with it, and takes a problem someone sees to the people who can act on it. It keeps the lake: prices, bars, trades, quotes and event contracts' outcomes from data plugins, licensed and entitled per dataset, and the book valued from them. Prepared changes keep a person in the loop of an agent's work; a deployment admin grants each plugin its accounts; and a plugin's autonomous work runs as a service account, preparing by default. The order path takes orders proposed, released, placed at a venue through a connectivity plugin and filled, their state decided by the book, with settlement calendars and venue-originated fills, through the released connectivity plugins Alpaca, Tradier, OANDA and SnapTrade. Booking books an order's executions to its accounts, and every instrument is named by the platform's INS- ID, a deployment keeping local records, never priced, until the platform answers. The analytics component answers plugins' jobs over the book and the lake, each answer naming its inputs, realized P&L and execution costs among them; venues' event contracts are grouped by event; and agents place orders on demo connections only. A placement states how it is executed, manually or by RFQ among the ways; FX orders net on one pair and value date; the lake keeps rates; and an ems checks its reference price's age before it places. Plugins and core report their latency, and a breach tells the people who can act. Listed options and futures are read as chains, minted when wanted, priced by the analytics component's option models and kept in the book through their lifecycle events, with package orders; a signal saves scenarios and derived series; a company's declared dividends reach the lake; and a starter pack installs from Browse or the CLI. The lake keeps the filings slice and quality states, and the deployment counts its data use. A plugin carries its own documentation, read before it is launched, and the platform's Community registry lists Open Meridian's own plugins.

By asset class. Equities, FX, Crypto, Options, Fixed income and Prediction markets each gather the pages above that their records, prices, orders and plugins use.