Dev Guide
Technical guides for OneStream development — from getting started to advanced patterns.
OneStream
What Is OneStream?
Understand OneStream as a unified Corporate Performance Management platform — what it replaces, how its engines work together, and why developers are central to extending it.
Updated February 16, 2026The OneStream Data Model
Learn how OneStream organizes data — dimensions, cubes, Scenario Types, Point of View, Data Units, and when to use relational tables instead of the cube.
Updated February 16, 2026Data Integration and Transformation
How data flows from source systems into OneStream — staging, mapping, transformation, and seeding actuals as the foundation for budgets and forecasts.
Updated February 16, 2026Building a Budget
Build a budget in OneStream from the ground up — driver-based planning, factor-based adjustments, Cube Views, calculations, and the workflow that ties it all together.
Updated February 16, 2026Forecasts and Custom Planning Solutions
Extend your budget into rolling forecasts, build variance analysis, and create bespoke CRUD processes for specialty planning like headcount and capital projects.
Updated February 16, 2026Cube Configuration
Configuring Cubes
Set up cubes in OneStream — cube properties, types, consolidation and translation algorithms, FX rates, data access, and integration settings.
Updated February 27, 2026Scenario Types and Cube Dimensions
Configure Scenario Types, assign dimensions by Scenario Type, and use horizontal extensibility to tailor your cube's data model per financial process.
Updated February 26, 2026Entity Dimension Setup
Configure entity members, relationship properties, intercompany settings, currencies, and parent adjustments — the structural backbone of cube consolidation.
Updated February 26, 2026Extensibility and Linked Cubes
Use vertical extensibility to tailor dimensions by business unit — connect cubes through entity hierarchy relationships and consolidate into a super cube.
Updated February 26, 2026Account Member Properties
Common dimension member properties and Account-specific settings — AccountType, FormulaType, AllowInput, IsConsolidated, aggregation, intercompany, constraints, and code examples.
Updated February 26, 2026Flow Member Properties
Flow dimension member properties — SwitchSign, SwitchType, FlowProcessingType, alternate input currency, and flow hierarchy design.
Updated February 26, 2026UD Member Properties
User-Defined dimension member properties — defaults, attribute members, IsAttributeMember, RelatedDimensionType, and UD constraints.
Updated February 26, 2026Dimension Library and Inheritance
The Dimension Library, dimension inheritance, stub dimensions (RootXXXDim), and creating new dimensions in OneStream.
Updated February 26, 2026Dimension Naming and Assignment
Member naming rules, restricted characters, reserved words, assigning dimensions to cubes, dimension levels, and best practices for initial setup.
Updated February 26, 2026Data Ingestion
Import, Validate, Load Overview
Understand the end-to-end IVL pipeline — how source data flows through the Stage Engine into the Cube, what each Workflow step does, and the status indicators that tell you where things stand.
Updated February 17, 2026Data Sources & Connectors
Configure Data Sources in OneStream — file types, connectors, data structure settings, cube assignments, and the options that control how source data is parsed before transformation.
Updated February 17, 2026Transformation Rules
How Transformation Rules map source data to Cube dimension members — rule groups, profiles, mapping types, wildcard syntax, derivative rules, and the reserved characters that will break your mappings.
Updated February 17, 2026The Import Step
What happens when you click Import — file parsing, the Stage Engine, Load Methods, and the right-click options that help you inspect and troubleshoot staged data.
Updated February 17, 2026The Validate Step
How OneStream validates staged data before loading to the Cube — Transformation Validation, Intersection Validation, how to fix each error type, and the Retransform workflow.
Updated February 17, 2026The Load Step
How validated data moves from Stage to the Cube — parallel loading by Entity, first-load vs. subsequent-load performance, multiple Import Children, and the partitioning strategies that keep large loads fast.
Updated February 17, 2026Standard vs. Direct Load
Compare the Standard and Direct Load Workflow types — feature differences, performance trade-offs, limitations of in-memory processing, and the recommended development-to-production approach.
Updated February 17, 2026Automating IVL
Automate the IVL pipeline with the ExecuteFileHarvestBatchParallel API, Workflow Event Handlers, Transformation Event Handlers, and partitioning strategies for high-volume batch loads.
Updated February 17, 2026Custom Relational Tables
Create and manage custom SQL tables in the OneStream application database — an alternative to the Cube for transactional data, lookup tables, configuration, and staging scenarios.
Updated February 17, 2026Business Rules
Getting Started with Business Rules
Learn the fundamentals of OneStream Business Rules — types, structure, and how to write your first rule.
Updated February 14, 2026Organizing Your Business Rule Code
Structure your Business Rules with class-level state, a thin Main dispatcher, and dedicated methods for each function type.
Updated February 14, 2026Debugging Business Rules
Learn the StringBuilder debug logging pattern — how to trace rule execution, understand class vs. function scope, and output debug logs through XFException.
Updated February 14, 2026Finance Rules
Getting Started with Finance Rules
Learn how Finance Business Rules work — function types, the rule skeleton, and execution flow.
Updated February 14, 2026Understanding Data Units
Learn how OneStream breaks calculations into Data Units and how to write efficient guard conditions for better performance.
Updated February 14, 2026Writing Calculations
Master stored calculation techniques in OneStream — api.Data.Calculate, Get/Set Data Buffers, CustomCalculate, and when to use Business Rules vs. Member Formulas.
Updated February 14, 2026The Finance Rules API
Explore the Finance Rules API object, the BRApi static class, BRGlobals caching, and how to share code across Business Rules.
Updated February 14, 2026Workspace Assemblies
Getting Started with Workspace Assemblies
Learn what workspace assemblies are, how they differ from Business Rules, and how to structure your code using workspaces, maintenance units, and the Service Factory pattern.
Updated February 14, 2026Referencing Assemblies and Sharing Code
Set up assembly dependencies, configure shared workspaces, and use reference syntax for XFBR, Dashboard, CubeView, and Service Factory configurations.
Updated February 14, 2026Referencing Dependency Classes in Code
Use the compiled namespace pattern to reference dependency classes in VB.NET and C# code, including Imports/using directives, MainClass patterns, and cross-workspace references.
Updated February 14, 2026