[Meta] Isomorphic actors — browser & edge program

[pathosDev]

Coordination umbrella — sequences the browser/edge tickets into one program with a clear on-ramp.

Rationale

No actor framework in any language runs the same actor code across server, browser and edge with a shared cluster story. We already have the unusual ingredients: MessageChannel transport, WebWorker backend, CRDTs, a WebSocket server actor, and a runtime abstraction layer. The pieces are ticketed individually (#210 browser ActorSystem, #215 cross-runtime cluster incl. browser, #209 WASM/edge) — this umbrella orders them and adds the client-side on-ramp (#435/#436).

Phases

1. Typed client on-ramp — [Feature] actor-ts/client — typed browser/frontend client (ask over WebSocket/HTTP) #435 (typed browser client) + [Feature] React/Vue/Svelte bindings for the actor-ts client (useActor, useAsk, useTopic) #436 (framework bindings): browsers talk to the cluster without being members.
2. Browser ActorSystem — [Feature] Browser-side ActorSystem with Web Workers #210: the actor programming model (spawn/tell/ask/supervision) in the browser, Web-Worker-backed.
3. Browser in the cluster — [Feature] Cross-runtime cluster (Bun + Node + Deno + Browser in one cluster) #215: browser nodes join as weakly-up, role-restricted members over a WebSocket/WebTransport transport (no shard hosting, no voting).
4. Edge runtimes — [Feature] WASM/Edge-runtime subpackage (Cloudflare Workers / Deno Deploy) #209: WASM/edge subpackage (Cloudflare Workers / Deno Deploy), persistence via the D1/libSQL backends from [Feature] Additional persistence backends: MongoDB, DynamoDB, MSSQL, libSQL/Turso, Cloudflare D1 (umbrella) #438.
5. Local-first showcase: offline-capable browser actors syncing state via the existing CRDT module — the demo that makes the story tangible.

// same actor code in the browser (#210), attached to the server cluster (#215):
const system = ActorSystem.create('ui');
const remote = await ClusterClient.connect('wss://api.example.com/cluster');
remote.send('shard/cart', { kind: 'add', sku: 'book-1' });

Documentation

Program page in the docs (EN + DE) once phase 1 lands; per-phase guides with the owning issues.

Acceptance (umbrella)

• Each phase issue references this program and its predecessor; the local-first demo exists as an example app by the end of phase 5.

Relates

Tracks: #435, #436, #210, #215, #209, #438 (D1/libSQL). Security constraints: browser members never hold shards or votes. Improvement program M7.

[pathosDev]

Design notes from the 2026-08 research for this program:

1. Push-based invocation with durable suspend-on-await is the serverless-native model — Restate pushes work to plain stateless HTTP/FaaS handlers that suspend while awaiting (native on Lambda/Workers/Vercel; https://docs.restate.dev/foundations/key-concepts), while Temporal's pull-based resident workers are the documented awkward fit — even its 2026 "Serverless Workers" launch is Lambda-only polling (https://docs.temporal.io/serverless-workers). When this program defines the edge/serverless invocation path, evaluate push + durable suspend as the native model.
2. True local-first remains unclaimed territory: Cloudflare's much-cited state sync is server-authoritative WebSocket broadcast — explicitly not offline/CRDT-merge local-first. Offline client writes merging via the CRDTs we already ship would go beyond [Feature] Actor state sync to connected clients — live state subscription over WebSocket (Rivet-class capability) #694 and beyond what the verified competitors offer. Worth a design spike when the typed client ([Feature] actor-ts/client — typed browser/frontend client (ask over WebSocket/HTTP) #435) exists.