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Couchbase Host Plugin Demo, Repo Reorganization & wasmCloud v2 RC8

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The March 11, 2026 wasmCloud Wednesday is hosted by Jeremy Fleitz for the first time (in the spirit of a rotating "host group" for the meeting). Jeremy demos a new Couchbase host plugin that ports the old wasmCloud Couchbase provider into the v2 host-plugin model, walks through the repo reorganization that moves wash into the main wasmCloud/wasmCloud monorepo with a release-1.9.x branch preserved, and Lucas Fontes shares the plan for v2 RC9 — the last RC, with Wasmtime 42, WASI P3 experimental support, and Pavel's fuel-tracking metrics. Eric introduces the new v2 templates and examples page as a single canonical source for component examples across languages.

Key Takeaways​

  • Couchbase host plugin demo — Jeremy reimplemented the old wasmcloud-provider-couchbase as a v2 host plugin, exposing get/upsert/delete over the Couchbase management REST API with credentials configurable at the host so workload components don't need to know the backend or auth
  • wash moved into the wasmCloud monorepo — the old wasmcloud/wash repo now lives as release-1.9.x and the wasmcloud/wasmcloud repo is the canonical v2 home; this is what RC8 builds against
  • wasmCloud v2 RC8 out, RC9 will be the last — Lucas confirmed RC9 will ship with Wasmtime 42 (the entry point for WASI P3 experiments) and Pavel's fuel-tracking PR, then v2 cuts at the next community call
  • Fuel tracking lands in v2 — Wasmtime fuel-consumption metrics emit from the host so users can see CPU-cycle usage per function and reason about cost or runaway components
  • v2 templates and examples page launched — Eric introduced the consolidated templates and examples page, explaining the difference between scaffolding templates and complete demonstration examples, with OCI references where they exist
  • Rotating host pattern — Bailey proposed and the team agreed: any of the maintainers with screen-sharing access can host wasmCloud Wednesday, with the agenda committed ahead of time and editable
  • Plumbers Summit videos are live — the Bytecode Alliance YouTube channel is publishing session videos, with road-to-component-model-1.0 and JCO breakdown blog posts coming as follow-ups
  • Conference run ahead — Wasm I/O in Barcelona next week, KubeCon EU in Amsterdam the week after; the team will host the next community call from the conference floor

Chapters​

Meeting Notes​

Couchbase Host Plugin Demo​

Jeremy Fleitz introduced the call as the first under a new "rotating host group" pattern (any maintainer with screen-share access can host) and dove straight into a demo of the new Couchbase host plugin he just landed in PR #4973. The plugin originates from a user request and is conceptually a port of the old wasmcloud-provider-couchbase from v1, restructured as a wasmCloud v2 host plugin rather than a separate provider process. Moving the capability into the host removes a hop, simplifies operation, and matches the v2 architectural direction where capabilities live in the host wherever they reasonably can.

The plugin uses the Couchbase management REST API and exposes a small WIT interface — a get, delete, and upsert (update) — for a Couchbase document type. Connection details (base URL, username, password) and the list of buckets the plugin is permitted to connect to are configured at the host level via environment variables, so the component doesn't need to know credentials or backend topology. That's a meaningful sandboxing improvement: a workload component can just say "I need Couchbase KV" via its WIT imports and let the host enforce which bucket it can actually reach, with the option of running multiple hosts with different bucket permissions.

The demo ran a local Couchbase server (port 8091), pointed wash dev at it on port 8000, and walked through get, upsert (including with TTL/expiry), and delete against a sample document.

ossfellow asked whether the new version still needs the WIT bindings (the way the old provider did with weak bindings). Jeremy clarified: the WIT bindings are still there — the host plugin implements the WIT interface for Couchbase documents and types — but the implementation now lives in the host rather than in a separate provider process.

Repo Reorganization​

Jeremy then walked through the repo reorganization that landed alongside RC8. The old wasmcloud/wash repo has been merged into the main wasmcloud/wasmcloud monorepo. To preserve continuity for the long-running v1 community, a release-1.9.x branch holds the pre-2.0 code in the wash repo. main on wasmcloud/wasmcloud is now where RC8 (and the upcoming RC9) is built, with a single canonical source of truth for v2.

Lucas on v2 RC9: Wasmtime 42, WASI P3, Fuel Tracking​

Lucas Fontes stepped in to share the plan for the final RC. RC9 will ship with Wasmtime 42, which is the version where wasmCloud begins dipping into WASI P3 — the next phase of the WASI specification. In addition, fuel tracking lands from Pavel's PR: Wasmtime emits CPU-cycle/fuel-consumption metrics from the host so users can see exactly how much compute each function call is using. That's a foundation for cost attribution, anomaly detection, and runaway-component identification.

Between this meeting and the next: merge remaining feature PRs (including fuel tracking), then spend the rest of the week through next week on testing and documentation — equalizing argument selection for wasi-keyvalue (now supports Redis, NATS, and in-memory simultaneously), tightening docs, and validating coexistence patterns. No more features after RC9 — what's in RC9 is what ships in v2. By the next community meeting, v2 should be out.

Eric's Templates and Examples Page​

Eric introduced the new v2 templates and examples page, a long-running gap in the wasmCloud docs. Previously, examples were sprawled across a TypeScript repo, a Go repo, and the main monorepo, with no clear story about which examples were compatible with which version. The new page provides a single canonical source of truth: templates (scaffolds for new projects) versus examples (complete applications demonstrating specific wasmCloud capabilities), broken down by language with OCI references where they exist. The page will keep expanding through the lead-up to the full v2 release.

Community Updates​

The team's conference run is starting: Wasm I/O in Barcelona next week (March 18-20) with Bailey and Liam on the ground, and KubeCon EU Amsterdam the week after (March 24-26) with most of the team. Jeremy flagged that next week's community call may be hosted live from Amsterdam — possibly just a brief hello-from-the-floor depending on timing. The Plumbers Summit videos are now live on the Bytecode Alliance YouTube channel — Eric confirmed two follow-up blog posts are coming, one on the road to component model 1.0 and one on JCO as a project.

The call wrapped with Liam Randall catching up with Matt Wilkinson (now at Capital One after stints at Roku and Google) — Matt was historically a big contributor to wash and the CLI, and the v2 release is timed well for re-engaging contributors who've been heads-down at day jobs.

WebAssembly News and Updates​

This week the WebAssembly ecosystem is preparing for two of its biggest events: Wasm I/O in Barcelona and KubeCon EU in Amsterdam. The wasmCloud v2 release is intentionally timed to coincide with this conference run — the v2 architecture (Kubernetes-native operator, runtime gateway, host plugin model) is the message the team wants in front of the broader cloud-native community in person. Wasmtime 42 is the first release where wasmCloud experiments with WASI P3, and the recently-published Plumbers Summit videos from the Bytecode Alliance go deep on what the road to component model 1.0 looks like.

What is wasmCloud?​

wasmCloud is a CNCF project for building and running WebAssembly components anywhere — cloud, edge, or Kubernetes. The v2 release walked through in this call introduces a host plugin model as a cleaner alternative to the v1 provider architecture: capabilities like Couchbase, Redis, and NATS now live inside the host process, configured at the host level (with credentials and access scoped at deploy time), and components import them through WIT interfaces. wasmCloud runs as a Kubernetes operator or standalone, with built-in OpenTelemetry observability, declarative workload deploys, signed-and-attested OCI artifact distribution, and now (in RC9 onward) Wasmtime fuel-consumption metrics.

Topic Deep Dive: Host Plugins vs Providers​

The Couchbase plugin demo is a useful concrete look at why wasmCloud v2 replaced the v1 provider model with host plugins. In v1, a provider was a separate process that components communicated with via NATS — flexible, language-agnostic, and good for capabilities that needed their own runtime. The trade-off: every request to a provider was a network hop, even when the provider lived on the same machine as the component, and the provider process needed its own deployment lifecycle, credentials, and operational story.

A host plugin moves the capability into the host. There's no NATS hop, no separate process, no separate deployment. Credentials and configuration are managed at the host level — which means the host operator can enforce that a workload only reaches certain buckets without trusting the component to behave. For platform engineers, that's a real reduction in operational surface area. For component authors, the interface stays the same (WIT) — they don't see the difference between a v1 provider and a v2 host plugin, which makes migration straightforward. Native plugins remain for cases that need direct hardware access (WebGPU); host plugins are the new default for everything else.

Who Should Watch This​

Couchbase users and Couchbase-adjacent platform engineers should watch Jeremy's full plugin demo starting at 06:14. wasmCloud v2 contributors want Lucas's RC9 plan at 17:53. Component developers evaluating wasmCloud should jump to Eric's templates and examples walkthrough at 20:49.

Up Next​

RC9 will land between this call and the next with Wasmtime 42, WASI P3 experimental support, and fuel tracking, after which v2 will be cut. The next wasmCloud Wednesday will be hosted live from Amsterdam during KubeCon EU. The wasmCloud team will be at Wasm I/O Barcelona next week and at the wasmCloud Project Pavilion booth at KubeCon EU the week after — stop by if you're attending either.

Get Involved​

wasmCloud is a CNCF project and contributions are welcome. Join the community:

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