🌌 What is SPHERE?
SPHERE (SaaS Pricing Holistic Evaluation and Regulation Environment) is an open-source, multi-tenant platform for treating SaaS pricing as an engineering artifact. It brings pricing design, version control, configuration-space analysis, dataset management, and pricing intelligence into one workspace.
The platform addresses a practical problem in SaaS engineering: plans and add-ons create a combinatorial configuration space, while pricing changes continuously as providers add capabilities, revise limits, and reposition products. SPHERE makes those changes inspectable and reproducible by representing each pricing as an iPricing, serializing it in the human-readable Pricing2Yaml format, and storing every revision as a versioned document.
This overview is based on SPHERE: A web platform for holistic SaaS pricing modelling, versioning, and analysis (SoftwareX). The paper describes SPHERE's multi-tenant architecture, pricing editor, Pricing Version Control System (PVCS), configuration-space analysis, and HARVEY pricing-intelligence assistant.
Scope
SPHERE supports the complete pricing lifecycle:
- Model a pricing in code or through the visual editor.
- Version each pricing revision and preserve stable YAML URLs.
- Organize related pricings into collections and organizations.
- Analyse configuration-space size, structure, and price ranges.
- Explore valid plan/add-on configurations interactively.
- Collaborate through organization membership, hierarchies, and granular permissions.
- Reason about pricing with HARVEY, using stored pricings, uploaded iPricings, or external pricing pages as context.
Core concepts
| Concept | Meaning in SPHERE |
|---|---|
| iPricing | The machine-oriented representation of a SaaS pricing. |
| Pricing2Yaml | The YAML syntax used to author, validate, exchange, and persist an iPricing. |
| Pricing version | An immutable revision of a pricing document, ordered over time and addressable through a stable URL. |
| Configuration space | The set of valid subscriptions produced by the plans, add-ons, features, and constraints in a pricing. |
| Organization | The ownership and access boundary for pricings and collections. |
| Collection | A curated, permission-aware group of related pricings. |
| PVCS | SPHERE's pricing version-control workflow: multiple versions, temporal analytics, and reproducible source files. |
Architecture
SPHERE separates the browser presentation layer, the application API, the data layer, and pricing-intelligence services. Nginx routes frontend traffic, API requests, static files, and HARVEY requests to their respective components. The frontend is a React single-page application; the backend is a TypeScript/Node.js Express API; MongoDB stores persistent entities; Redis caches expensive configuration-space computations.
The API integrates pricing4ts to parse Pricing2Yaml and exposes configuration-space results through the UI. HARVEY uses PRIME and A-MINT as tools: PRIME computes and optimizes valid configurations, while A-MINT extracts pricing information from external SaaS pages.
Pricing intelligence capabilities
SPHERE combines four operations that are often separated across pricing tools:
- Authoring: the code editor gives technical users immediate syntax feedback and a rendered pricing table; the visual editor exposes the same model to users who do not want to learn YAML first.
- Analysis: each version receives configuration-space metrics, plan and feature counts, usage-limit classifications, and minimum/maximum subscription prices. Redis caches these results so repeated inspection does not invoke the solver unnecessarily.
- Exploration: versions with up to 2,000 valid configurations expose every configuration through a searchable, plan-filterable explorer.
- Assistance: HARVEY answers natural-language questions with a pricing version as context, compares stored or external pricings, and delegates extraction and optimization to A-MINT and PRIME.
These operations make a pricing change traceable: a user can edit a source document, publish a new version, inspect how its configuration space changed, and use the resulting data in an integration or research workflow.
Integration and communication
SPHERE is designed to sit alongside pricing-driven development tools rather than replace the application that consumes a pricing. The web interface communicates with the API over HTTP(S); server-sent events deliver platform notifications to the browser. External tools can call the same API with a bearer token or scoped API key, download a stable Pricing2Yaml URL, or use the OpenAPI contract to generate a client.
Keep the API behind the deployment's trusted boundary when possible. Public pricing pages and HARVEY extraction URLs are intentionally different from authenticated management operations: the former support discovery, while the latter enforce organization and entity permissions.
Research and teaching use
The SoftwareX paper reports SPHERE's use in software-engineering education, pricing-evolution studies, pricing-driven self-adaptation, and the consolidation of research artifacts such as Pricing2Yaml, the iPricing metamodel, configuration-space analysis, and automated pricing extraction. That provenance explains the platform's emphasis on reproducible versions, permanent source URLs, organization-aware access control, and analytics that can be compared over time.
Multi-tenancy and access control
Every account receives a personal organization. Users can create additional organizations, invite collaborators, and create parent/child hierarchies. Administrative authority is inherited from a parent organization to its descendants.
Within an organization, the roles are:
- Owner: full control over resources, members, roles, and settings.
- Admin: resource and membership management, except demoting another administrator or performing owner-only operations.
- Member: no implicit unrestricted access; permissions are granted explicitly.
Permission flags are evaluated at the organization, collection, and pricing scopes. A collection-level permission takes precedence for the pricings it contains. API-key scopes provide an additional upper bound: view keys expose member-level operations, management keys expose at most admin-level operations, and all keys preserve the user's authorized role.
Where to go next
- Follow the user guide for UI workflows.
- Read the SPHERE API reference for programmatic integration.
- Consult the Pricing2Yaml syntax when authoring files.
- Review the SPHERE repository for deployment and development instructions.