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3rd November 2026Critter Stack AI Skills 1.18: Caught Up With CritterWatch 1.2AI Skills 1.18 brings every CritterWatch skill up to the 1.2 MCP tools, checked tool by tool against the source: a new sagas skill, the get_command_outcome tool, dead letters ranged by failure time, event queries over bodies and metadata, and six corrections to advice that had gone wrong, including the Prometheus series names every Grafana example used.
3rd November 2026CritterWatch 1.2: See Inside Your Event Store, Documents, Sagas and SchedulesCritterWatch 1.2 turns the console into a real explorer for what your Critter Stack services hold: an overview of every event store, a Step Through tab for projections, a Document Store Explorer that checks your documents still deserialize, saga instances with their state and pending timeouts, a Schedule Explorer that tells you what a schedule is actually doing, and an Event Model you can drill into.
30th October 2026Critter Stack in Review: October 12th to 30thThree weeks, 72 tagged releases, and 57 pull requests from 18 people outside JasperFx. The big themes were not losing messages, with a durable inbox and outbox hardening pass that closed a dozen community-reported ways a message could go missing; performance, from SQL Server index seeks to a thread pool thread the run command was quietly eating; shutting down cleanly; an async daemon that heals itself; and multi-tenancy at a scale we'd never tested before. Plus Marten's hard stream delete, Aspire parity in Wolverine, NServiceBus XML interop, and the upgrade notes you should read first.
29th October 2026Failure Groups: Handle a Dead Letter Incident as One ThingCritterWatch 1.1 groups dead letters by the failure that caused them, across every service and database, and lets you replay, archive, restore or discard the whole group as one tracked operation with a reason attached. Your AI agent gets the same loop over MCP, and still has to show you the preview before it deletes anything.
27th October 2026CritterWatch 1.1, Bobcat 1.0, AI Skills 1.17, and a First Look at StoatOne release wave, four products: CritterWatch 1.1 with 83 MCP tools, cron schedules, a Document Explorer and a long list of scalability fixes earned on real systems; Bobcat 1.0, the successor to Storyteller and our answer for spec-driven development; AI Skills 1.17; and the first public preview of Stoat.27th October 2026Critter Stack AI Skills 1.17: One Month of Releases, Checked Against the SourceAI Skills 1.17 is the result of a review of everything Wolverine, Marten, CritterWatch, Bobcat and Stoat shipped in the last month, checked against the product source rather than the changelogs. Thirty-six skill changes, seven of them correcting advice that had quietly gone wrong, and the CritterWatch 1.1 paired updates that were waiting in 1.16.
25th October 2026Dead Letter Management in CritterWatch 1.1Bulk replay that acts on exactly what it counted, edit-and-replay with a full audit trail, every operation followed to the end across every database, and an MCP server that lets an AI agent triage your dead letters, but asks before it deletes anything.
19th October 2026Rebuilding Projections Without DowntimeWolverine 6.51 adds a warm-up node role for blue/green deployments: spin up the new release's nodes with no messaging at all, let them rebuild the new versions of your Marten or Polecat projections off to the side, and only cut over once they've caught up. Here's how that fits together with Marten's versioned projections, Wolverine's capability-based agent assignment, and the new side-effect gate, and why a client with a very large system and a habit of revising projections needed all of it.12th October 2026Critter Stack Week in Review: October 5th to 12thBobcat went from 0.31 to 0.50 and dropped its Gherkin lane for a projected-only model, WolverineFx.Bobcat shipped, and the whole Event Modeling to specs to scaffolding workflow got a tutorial ahead of tomorrow's live stream. Nineteen pull requests from fourteen people outside JasperFx, headlined by a NATS JetStream hardening pass and a 66 minute leader election brought down to seconds. Plus SQL Server ordered envelope ids, Marten's FetchForWriting consistency fixes, and the LINQ projection surface working under Native AOT.
7th October 2026Wolverine's End to End Multi-TenancyWolverine treats the tenant id as message metadata, and that one decision carries the tenant from HTTP detection, into the right Marten, Polecat, or EF Core session, onto every cascaded message, and into the only transactional inbox and outbox in .NET that lives in each tenant's own database. Here's how the whole chain works, and why it took years to get right.
5th October 2026Our Busiest Week Ever: The Critter Stack from September 28th to October 5thForty releases, 267 merged pull requests, and 38 of those from eleven people outside JasperFx. Native AOT went from aspirational to measured in CI across Marten, Wolverine, Polecat, and Fisher. Weasel picked up a Firebird provider and a pile of MySQL, Oracle, and SQLite fixes from the Quartz.NET maintainer. Wolverine's global partitioning got hardened by a user running it hard in a real cluster. And Polecat and Fisher kept pace with Marten the whole way.
30th September 2026Event Sourcing on SQL Server with PolecatIf your shop runs on SQL Server and you've been eyeing Event Sourcing, Polecat is the most full featured event store you can get for SQL Server in .NET. It's built on the same shared infrastructure and a decade of production lessons from Marten, it has a first class Wolverine integration for CQRS, CritterWatch can monitor it, and JasperFx Software supports it. Here's the tour.23rd September 2026Critter Stack AI Skills 1.14: Troubleshooting Guides, and Why the Skills Pay for ThemselvesAI Skills 1.14 ships eight troubleshooting skills that decode Critter Stack exceptions from the stack trace. It's also a good excuse to make the bigger case: skills that know Wolverine's idioms produce terser code, cheaper agent sessions, and an agent that can actually reason through concurrency, parallelism, and production diagnostics.
16th September 2026Full-Text, Vector, and Hybrid Search in Polecat, Fisher, and MartenPolecat, Fisher, and Marten now share one search surface: full-text search, vector similarity search with filters, hybrid search fused by reciprocal rank fusion, and event-sourced vector projections, on SQL Server 2025, SQLite, and PostgreSQL. Here's what each store gives you, how it works, and where they differ.27th August 2026Change Documents Without Loading Them: The Patching API in Marten, Polecat, and FisherThe Critter Stack's Patching API lets you modify persisted JSON documents in place -- no deserialize, mutate, re-serialize round trip. Here's the shared API across Marten, Polecat, and Fisher, what each database does underneath, and where the three genuinely differ.
26th August 2026Alerts and the Timeline in CritterWatch 1.0CritterWatch 1.0 is watching your system for unusual conditions and trying to explain the cause and effect of anything that's going wrong.
20th August 2026CritterWatch 1.0: Stop Guessing What Your Critter Stack Is DoingCritterWatch 1.0 is here — a monitoring and production-management console purpose-built for Wolverine, Marten, Polecat, and Fisher. It renders the system you actually shipped from the running code, steps through projections event by event, lets you replay dead letters and rebuild projections without a redeploy, and hands your AI agent a real, RBAC-gated control surface.
18th August 2026Meet Fisher, and One Handler Across Three Databases: The Critter Stack Since August 2ndSixty-three releases in sixteen days across Marten, Wolverine, Polecat, Fisher, Weasel, and the shared JasperFx libraries. Fisher brings event sourcing and document storage to SQLite with no server at all, the shared contracts wave means the same Wolverine handler now runs on PostgreSQL, SQL Server, or SQLite without naming a store, and a projection loader bug that silently skipped events makes this an upgrade you should not sit on.
11th August 2026Event Sourcing Without the Eventual Consistency Tax: Strong Consistency Options in Marten and PolecatMost event sourcing stacks make eventual consistency mandatory: events in one database, read models in another, and a subscription in between. Marten and Polecat keep events and read models in one database, which unlocks a dial no one else offers — projections snapshotted in the same transaction as the events, FetchLatest reads that are accurate even with async projections, wait-for-non-stale queries, and test automation that makes asynchronous projections actually testable.5th August 2026Metadata All the Way Down: Correlation, Causation, and Headers Across Wolverine, Marten, and PolecatEvery serious event sourced system eventually needs to answer 'what caused this event, and who did it?' The Critter Stack establishes correlation, causation, saga, user, and tenant metadata on Wolverine message envelopes — seeded straight from OpenTelemetry activities — then relays all of it onto the events Marten and Polecat store, with storage you can dial from lean to rich.2nd August 2026A Week in the Critter Stack: Security, Preventing Data Loss, and Rolling PartitionsSeven days, twenty-two releases across Marten, Wolverine, Polecat, Weasel, and JasperFx: a PostgreSQL injection fix under sharded tenancy, two silent data-loss bugs in Wolverine, self-managing time-series partitions, and a big wave of production hardening for projection agent distribution.
7th July 2026How the Critter Stack Got to AOT ComplianceThree years after "it's going to take a long time", every JasperFx library publishes AOT and trim clean. How a stack built on runtime code generation got there without giving up its performance story.11th June 2026Polecat: A SQL Server-Native Event Store and Document DatabasePolecat is an event store and lightweight document database for .NET, backed by SQL Server 2025. It brings the proven Marten development model — same IDocumentStore API, projections, and async daemon — to SQL Server shops without a database migration.24th May 2026Marten 9.0, Polecat 4.0, and Wolverine 6.0 are Live!The Critter Stack 2026 releases have landed: faster cold starts, AOT compliance, better Serverless support, and new greenfield defaults across Marten, Polecat, and Wolverine.22nd March 2026Announcing Polecat: Event Sourcing with SQL ServerPolecat is a new JasperFx library that brings Marten's proven Event Sourcing and document database model to SQL Server 2025 — the best technical option for Event Sourcing with SQL Server in .NET.
Polecat
Posts tagged Polecat
3rd November 2026Critter Stack AI Skills 1.18: Caught Up With CritterWatch 1.2AI Skills 1.18 brings every CritterWatch skill up to the 1.2 MCP tools, checked tool by tool against the source: a new sagas skill, the get_command_outcome tool, dead letters ranged by failure time, event queries over bodies and metadata, and six corrections to advice that had gone wrong, including the Prometheus series names every Grafana example used.3rd November 2026CritterWatch 1.2: See Inside Your Event Store, Documents, Sagas and SchedulesCritterWatch 1.2 turns the console into a real explorer for what your Critter Stack services hold: an overview of every event store, a Step Through tab for projections, a Document Store Explorer that checks your documents still deserialize, saga instances with their state and pending timeouts, a Schedule Explorer that tells you what a schedule is actually doing, and an Event Model you can drill into.30th October 2026Critter Stack in Review: October 12th to 30thThree weeks, 72 tagged releases, and 57 pull requests from 18 people outside JasperFx. The big themes were not losing messages, with a durable inbox and outbox hardening pass that closed a dozen community-reported ways a message could go missing; performance, from SQL Server index seeks to a thread pool thread the run command was quietly eating; shutting down cleanly; an async daemon that heals itself; and multi-tenancy at a scale we'd never tested before. Plus Marten's hard stream delete, Aspire parity in Wolverine, NServiceBus XML interop, and the upgrade notes you should read first.29th October 2026Failure Groups: Handle a Dead Letter Incident as One ThingCritterWatch 1.1 groups dead letters by the failure that caused them, across every service and database, and lets you replay, archive, restore or discard the whole group as one tracked operation with a reason attached. Your AI agent gets the same loop over MCP, and still has to show you the preview before it deletes anything.27th October 2026CritterWatch 1.1, Bobcat 1.0, AI Skills 1.17, and a First Look at StoatOne release wave, four products: CritterWatch 1.1 with 83 MCP tools, cron schedules, a Document Explorer and a long list of scalability fixes earned on real systems; Bobcat 1.0, the successor to Storyteller and our answer for spec-driven development; AI Skills 1.17; and the first public preview of Stoat.27th October 2026Critter Stack AI Skills 1.17: One Month of Releases, Checked Against the SourceAI Skills 1.17 is the result of a review of everything Wolverine, Marten, CritterWatch, Bobcat and Stoat shipped in the last month, checked against the product source rather than the changelogs. Thirty-six skill changes, seven of them correcting advice that had quietly gone wrong, and the CritterWatch 1.1 paired updates that were waiting in 1.16.25th October 2026Dead Letter Management in CritterWatch 1.1Bulk replay that acts on exactly what it counted, edit-and-replay with a full audit trail, every operation followed to the end across every database, and an MCP server that lets an AI agent triage your dead letters, but asks before it deletes anything.19th October 2026Rebuilding Projections Without DowntimeWolverine 6.51 adds a warm-up node role for blue/green deployments: spin up the new release's nodes with no messaging at all, let them rebuild the new versions of your Marten or Polecat projections off to the side, and only cut over once they've caught up. Here's how that fits together with Marten's versioned projections, Wolverine's capability-based agent assignment, and the new side-effect gate, and why a client with a very large system and a habit of revising projections needed all of it.12th October 2026Critter Stack Week in Review: October 5th to 12thBobcat went from 0.31 to 0.50 and dropped its Gherkin lane for a projected-only model, WolverineFx.Bobcat shipped, and the whole Event Modeling to specs to scaffolding workflow got a tutorial ahead of tomorrow's live stream. Nineteen pull requests from fourteen people outside JasperFx, headlined by a NATS JetStream hardening pass and a 66 minute leader election brought down to seconds. Plus SQL Server ordered envelope ids, Marten's FetchForWriting consistency fixes, and the LINQ projection surface working under Native AOT.7th October 2026Wolverine's End to End Multi-TenancyWolverine treats the tenant id as message metadata, and that one decision carries the tenant from HTTP detection, into the right Marten, Polecat, or EF Core session, onto every cascaded message, and into the only transactional inbox and outbox in .NET that lives in each tenant's own database. Here's how the whole chain works, and why it took years to get right.5th October 2026Our Busiest Week Ever: The Critter Stack from September 28th to October 5thForty releases, 267 merged pull requests, and 38 of those from eleven people outside JasperFx. Native AOT went from aspirational to measured in CI across Marten, Wolverine, Polecat, and Fisher. Weasel picked up a Firebird provider and a pile of MySQL, Oracle, and SQLite fixes from the Quartz.NET maintainer. Wolverine's global partitioning got hardened by a user running it hard in a real cluster. And Polecat and Fisher kept pace with Marten the whole way.30th September 2026Event Sourcing on SQL Server with PolecatIf your shop runs on SQL Server and you've been eyeing Event Sourcing, Polecat is the most full featured event store you can get for SQL Server in .NET. It's built on the same shared infrastructure and a decade of production lessons from Marten, it has a first class Wolverine integration for CQRS, CritterWatch can monitor it, and JasperFx Software supports it. Here's the tour.23rd September 2026Critter Stack AI Skills 1.14: Troubleshooting Guides, and Why the Skills Pay for ThemselvesAI Skills 1.14 ships eight troubleshooting skills that decode Critter Stack exceptions from the stack trace. It's also a good excuse to make the bigger case: skills that know Wolverine's idioms produce terser code, cheaper agent sessions, and an agent that can actually reason through concurrency, parallelism, and production diagnostics.16th September 2026Full-Text, Vector, and Hybrid Search in Polecat, Fisher, and MartenPolecat, Fisher, and Marten now share one search surface: full-text search, vector similarity search with filters, hybrid search fused by reciprocal rank fusion, and event-sourced vector projections, on SQL Server 2025, SQLite, and PostgreSQL. Here's what each store gives you, how it works, and where they differ.27th August 2026Change Documents Without Loading Them: The Patching API in Marten, Polecat, and FisherThe Critter Stack's Patching API lets you modify persisted JSON documents in place -- no deserialize, mutate, re-serialize round trip. Here's the shared API across Marten, Polecat, and Fisher, what each database does underneath, and where the three genuinely differ.26th August 2026Alerts and the Timeline in CritterWatch 1.0CritterWatch 1.0 is watching your system for unusual conditions and trying to explain the cause and effect of anything that's going wrong.20th August 2026CritterWatch 1.0: Stop Guessing What Your Critter Stack Is DoingCritterWatch 1.0 is here — a monitoring and production-management console purpose-built for Wolverine, Marten, Polecat, and Fisher. It renders the system you actually shipped from the running code, steps through projections event by event, lets you replay dead letters and rebuild projections without a redeploy, and hands your AI agent a real, RBAC-gated control surface.18th August 2026Meet Fisher, and One Handler Across Three Databases: The Critter Stack Since August 2ndSixty-three releases in sixteen days across Marten, Wolverine, Polecat, Fisher, Weasel, and the shared JasperFx libraries. Fisher brings event sourcing and document storage to SQLite with no server at all, the shared contracts wave means the same Wolverine handler now runs on PostgreSQL, SQL Server, or SQLite without naming a store, and a projection loader bug that silently skipped events makes this an upgrade you should not sit on.11th August 2026Event Sourcing Without the Eventual Consistency Tax: Strong Consistency Options in Marten and PolecatMost event sourcing stacks make eventual consistency mandatory: events in one database, read models in another, and a subscription in between. Marten and Polecat keep events and read models in one database, which unlocks a dial no one else offers — projections snapshotted in the same transaction as the events, FetchLatest reads that are accurate even with async projections, wait-for-non-stale queries, and test automation that makes asynchronous projections actually testable.5th August 2026Metadata All the Way Down: Correlation, Causation, and Headers Across Wolverine, Marten, and PolecatEvery serious event sourced system eventually needs to answer 'what caused this event, and who did it?' The Critter Stack establishes correlation, causation, saga, user, and tenant metadata on Wolverine message envelopes — seeded straight from OpenTelemetry activities — then relays all of it onto the events Marten and Polecat store, with storage you can dial from lean to rich.2nd August 2026A Week in the Critter Stack: Security, Preventing Data Loss, and Rolling PartitionsSeven days, twenty-two releases across Marten, Wolverine, Polecat, Weasel, and JasperFx: a PostgreSQL injection fix under sharded tenancy, two silent data-loss bugs in Wolverine, self-managing time-series partitions, and a big wave of production hardening for projection agent distribution.7th July 2026How the Critter Stack Got to AOT ComplianceThree years after "it's going to take a long time", every JasperFx library publishes AOT and trim clean. How a stack built on runtime code generation got there without giving up its performance story.11th June 2026Polecat: A SQL Server-Native Event Store and Document DatabasePolecat is an event store and lightweight document database for .NET, backed by SQL Server 2025. It brings the proven Marten development model — same IDocumentStore API, projections, and async daemon — to SQL Server shops without a database migration.24th May 2026Marten 9.0, Polecat 4.0, and Wolverine 6.0 are Live!The Critter Stack 2026 releases have landed: faster cold starts, AOT compliance, better Serverless support, and new greenfield defaults across Marten, Polecat, and Wolverine.22nd March 2026Announcing Polecat: Event Sourcing with SQL ServerPolecat is a new JasperFx library that brings Marten's proven Event Sourcing and document database model to SQL Server 2025 — the best technical option for Event Sourcing with SQL Server in .NET.