Our Products
The Critter Stack — Open Source
The Critter Stack is a suite of open source .NET libraries for building server-side applications with Event Sourcing, CQRS, document storage, and asynchronous messaging. JasperFx Software offers consulting services and support plans for all of these tools.
Marten
Transactional document database and event store built on PostgreSQL. The most full-featured Event Sourcing library on .NET.
Documentation ➔
Wolverine
Next-generation command bus, message bus, and mediator for .NET. Powerful asynchronous messaging with minimal ceremony.
Documentation ➔
Polecat
.NET event store and document database on SQL Server 2025. Bringing the Critter Stack experience to SQL Server.
Documentation ➔
Weasel
Database schema management for PostgreSQL, SQL Server, and SQLite.
Documentation ➔
Alba
Fast and expressive integration testing for ASP.NET Core web services.
Documentation ➔
JasperFx (Shared Libraries)
Common utilities and infrastructure shared across the Critter Stack ecosystem.
Documentation ➔Commercial Products
CritterWatch
From dev-time insight to production control for Wolverine, Marten, and Polecat — for you and your AI agents.
Pick the plan that fits your scale.
Free
- Maximum Services3
- Alerts—
- Audit Logs—
- Custom Thresholds—
- MultiTenancy—
- Operations—
- License Needed—
Professional
- Maximum Services25
- Alerts✓
- Audit Logs✓
- Custom Thresholds✓
- MultiTenancy✓
- Operations✓
- License Needed✓
Enterprise
- Maximum ServicesUnlimited
- Alerts✓
- Audit Logs✓
- Custom Thresholds✓
- MultiTenancy✓
- Operations✓
- License Needed✓
You can request a trial license to evaluate CritterWatch before you buy.
CritterStack AI Skills
AI-powered development accelerators for the Critter Stack — speed up your workflow with intelligent code assistance. Annual licenses; pick the tier that fits your team size.
🐛 Found a bug or have a feature request? Report and track issues for CritterWatch, the AI Skills, and our other commercial products in our public ProductSupport issue tracker on GitHub.
💬 Have questions about our commercial products? Contact us and we'll be happy to help.
See the Critter Stack in Action
Multi-Tenancy in the Critter Stack
Event Sourcing and CQRS with the Critter Stack
Vertical Slices the Critter Stack Way