Release Notes

1.0.0

Released 19 August 2026 — the first stable release of CritterWatch.

CritterWatch is a monitoring and production-management console for Critter Stack systems. It gives you — and your AI agents — a live view of every Wolverine service, Marten and Polecat event store, and the controls to act on what you find.

1.0 marks the point where the API surface, the package lineup, and the storage model are stable and supported. Everything below has been through the full release gate on all three storage flavours.

Install

Pick the package matching the database you want CritterWatch's own console storage to use. This is independent of what your monitored services run — a console on SQLite can happily monitor a fleet of PostgreSQL-backed services.

Package	Console storage	When to reach for it
CritterWatch	Marten / PostgreSQL	The default. Most Critter Stack shops already run Postgres
CritterWatch.SqlServer	Polecat / SQL Server	Shops standardised on SQL Server
CritterWatch.Sqlite	Fisher / SQLite	Local development, demos, and single-node deployments — needs no database server at all

dotnet add package CritterWatch

Then see the Quick Start. Monitored services add Wolverine.CritterWatch, which is store-agnostic — it depends only on the JasperFx.Events abstractions, so a service on RavenDB, EF Core, or no event store at all can be monitored without pulling Marten in.

What is in 1.0

Understand your system, not just watch it. CritterWatch is as much a development tool as a production one. It renders live event models, your real store schema and DDL, the generated handler and projection source Wolverine actually runs, and full HTTP endpoint chains — the ground truth rather than your mental model of it.

The Projection Stepper replays a projection over a real slice of your event store and walks you through the before/after state row by row, with a JSON diff at each step. It is the fastest available answer to "why is this aggregate shaped like that at version N?"

Real-time monitoring of service health, nodes, agents, throughput and error rates, pushed over SignalR as events happen rather than polled.

Dead letter queue management across every service from one view — query, filter, replay, edit-and-replay, discard, in batches, with exception grouping and CSV export.

Projection operations — track async projection lag, spot stalls, and pause, restart, rebuild or rewind from the console with no code change and no service restart.

Event-sourced alerting with a complete lifecycle — raised, elevated, reduced, resolved, cleared — stored as immutable events, so the alert history is auditable rather than a current-state table that forgets.

Multi-tenancy — add, disable and remove tenants at runtime, with per-tenant metrics, DLQ filtering and projection health.

An MCP server for AI agents. Point Claude or any MCP client at one endpoint and it can query every monitored service — spans by saga or stream, projection lag, dead letters, alerts, metrics — and take action, tenant-scoped and RBAC-gated.

Licensing

CritterWatch is free to use in read-only monitoring mode. Connect as many services as you like and watch your whole Critter Stack with no license key.

A commercial license unlocks every administrative action — DLQ replay, projection rebuilds, listener and node control, tenant management — and the entire MCP server.

Supported stack

1.0.0 is built and gated against:

.NET	9.0 and 10.0
Wolverine	6.29.1
Marten	9.28.0
Polecat	5.19.0
Fisher	1.0.0
JasperFx / JasperFx.Events	2.52.1

Upgrading from a release candidate

No configuration changes are required from 1.0.0-rc.10.

⚠️ If you are coming from a build older than rc.10 and ran an embedded console, note that CritterWatch.Embedded was removed before 1.0 — the console now runs as its own host. Its storage collapsed to a single store at the same time: console data lives in the critterwatch schema and Wolverine durability in critterwatch_wolverine. No table moved, but an upgraded database may still carry orphaned critterwatch.wolverine_* tables from the old two-store layout. Nothing reads them and they can be dropped.

Getting help

1.0 closed 282 issues across ten release candidates, beginning 27 July 2026.

Questions, bug reports and feature requests are welcome in the Critter Stack Discord, and licensed customers can reach us through the support address on their license.