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Critter Stack AI Skills 1.18: Caught Up With CritterWatch 1.23rd 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.CritterWatch 1.2: See Inside Your Event Store, Documents, Sagas and Schedules3rd 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.Critter Stack in Review: October 12th to 30th30th 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.Failure Groups: Handle a Dead Letter Incident as One Thing29th 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.CritterWatch 1.1, Bobcat 1.0, AI Skills 1.17, and a First Look at Stoat27th 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.Critter Stack AI Skills 1.17: One Month of Releases, Checked Against the Source27th 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.Dead Letter Management in CritterWatch 1.125th 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.Succeeding with Test Automation using Bobcat20th October 2026Succeeding with Test Automation using BobcatBobcat is the Critter Stack's new spec-driven integration testing framework, and we have already used it to make our own CI builds and local gating faster and more trustworthy. This is the test automation strategy behind it: fifteen recommendations, and where Bobcat does the job.Rebuilding Projections Without Downtime19th 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.15th October 2026Wolverine's Agent Assignment at ScaleHow Wolverine's leadership election and agent assignment subsystem grew up: why it exists, what 512 databases and 18,000 agents taught us about reassignment swarms and hysteresis, how we test it now, and a preview of dedicated warm-up nodes for blue/green projection deployments.Critter Stack Week in Review: October 5th to 12th12th 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.Introducing Bobcat: Spec Driven Development and Better Integration Testing for the Critter Stack6th October 2026Introducing Bobcat: Spec Driven Development and Better Integration Testing for the Critter StackBobcat is the new Critter Stack tool for Spec Driven Development and for making our own integration testing more reliable. It projects readable specifications out of the xUnit.net or TUnit tests you already have, brings back the table driven testing ideas from Storyteller, reports failures in a way an AI agent can actually use, and has a compiled Gherkin model for when Given/When/Then is the right fit.Our Busiest Week Ever: The Critter Stack from September 28th to October 5th5th 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.24th September 2026CritterWatch 1.1: Run the Console Inside Your Own ApplicationCritterWatch 1.1 adds embedded mode — mount the monitoring console inside the Wolverine application you already run, on the PostgreSQL you already have, with no second deployment and no message broker. Two calls, one database, and the console watches the app it lives in.Critter Stack AI Skills 1.14: Troubleshooting Guides, and Why the Skills Pay for Themselves23rd 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.21st September 2026Every Lever Marten Gives You for Scaling a Big Event Sourcing SystemA tour of everything in Marten and Wolverine for scaling large event sourced systems: Quick Append, hot/cold event archiving, stream compacting, binary event serialization, read replicas, per-tenant partitioning, database per tenant and sharding, ancillary stores per module, projection lifecycles, strongly consistent async projections, partitioned projection data, and Wolverine-managed projection distribution.Full-Text, Vector, and Hybrid Search in Polecat, Fisher, and Marten16th 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.9th September 2026Event Sourcing Quick Start with MartenLet's get up and running with event sourcing using MartenAsk Your Codebase: AI Skills and the Critter Stack Command Line2nd September 2026Ask Your Codebase: AI Skills and the Critter Stack Command LineA recorded session pointing an AI agent at a Critter Stack codebase with nothing but the built-in CLI diagnostics and the JasperFx AI Skills — no console, no MCP server, no running fleet. Where is this message routed? What is actually durable? Why isn't the outbox working? And the new projection-run command stepping through a broken projection one event at a time.Interrogating Your Running System with CritterWatch's MCP Server31st August 2026Interrogating Your Running System with CritterWatch's MCP ServerA real, recorded session of an AI agent triaging a Wolverine system through CritterWatch's MCP server — summarizing and replaying dead letters, explaining a message's full journey from its OpenTelemetry spans, chasing down a poisoned projection with the projection stepper, and interrogating the alert subsystem. Plus how the JasperFx AI Skills teach the agent to do all of this well.Change Documents Without Loading Them: The Patching API in Marten, Polecat, and Fisher27th 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.CritterWatch 1.0: Stop Guessing What Your Critter Stack Is Doing20th 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.What a Critter Stack Workshop Actually Looks Like14th August 2026What a Critter Stack Workshop Actually Looks LikeWe've run Critter Stack workshops for several teams now, and no two have been the same. One went deep on asynchronous messaging, another on Wolverine's HTTP endpoint and message handler hybrids, a third on using Marten projections to build denormalized views for reporting screens. The material is built and ready — what it turns into depends on what your team actually needs.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.A Week in the Critter Stack: Security, Preventing Data Loss, and Rolling Partitions2nd 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.Onboard a Tenant Without a Deployment: Runtime Multi-Tenancy in CritterWatch28th July 2026Onboard a Tenant Without a Deployment: Runtime Multi-Tenancy in CritterWatchCritter Stack services can add, disable, and remove tenants at runtime — new databases and all. CritterWatch turns that capability into an operator console: a tenant lifecycle you can drive from a browser, and performance metrics broken down per tenant id.22nd July 2026Smarter LINQ: Pushing More of Your Query Into PostgreSQLRecent Marten work widens what your LINQ Where/Select expressions translate into PostgreSQL SQL and JSONPath -- so more of your query runs in the database instead of falling back to slower client-side evaluation.21st July 2026Never Skip an Event: Hardening Marten's High Water DetectionA deep look at the recent hardening of Marten's async projection high water detection -- why an in-flight transaction gap is dangerous, and how transaction evidence keeps projections from ever silently skipping an event.How the Critter Stack Got to AOT Compliance7th 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.Marten 9.0, Polecat 4.0, and Wolverine 6.0 are Live!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.12th April 2026The Fastest Possible HTTP Queries with MartenHow to build the most efficient possible HTTP query endpoints in .NET by streaming JSON straight from PostgreSQL with Marten — using Marten.AspNetCore's WriteArray and compiled queries with zero C# allocation.Official Support Plans for Marten and Wolverine15th November 2023Official Support Plans for Marten and WolverineJasperFx Software now offers formal paid support for Marten, Wolverine, and the rest of the Critter Stack, so teams can adopt the tools for mission critical systems with a company behind them.PostgreSQL Superpowers in Action at BuildStuff15th November 2023PostgreSQL Superpowers in Action at BuildStuffOskar Dudycz's BuildStuff talk on what PostgreSQL can do beyond plain tables, and how Marten puts those capabilities to work.The Critter Stack at .NET 202315th November 2023The Critter Stack at .NET 2023Jeremy's .NET 2023 talk on CQRS with Event Sourcing using Marten and Wolverine: lower code ceremony, a great local developer story, testable domain logic, and built-in diagnostics.27th July 2023Marten as Document DatabaseWhy a document database, why PostgreSQL, and why Marten: the thinking behind Marten's document model, with a CoDe Magazine deep dive and Jeremy's CitusCon 2023 talk.27th July 2023Marten as Event StoreMarten pairs its document database with a full event store on PostgreSQL. A short orientation, with pointers to the CoDe Magazine article and Oskar's NDC Oslo 2023 talk.