worldwideview-plugin-creation

name	worldwideview-plugin-creation
description	Use when creating a new plugin, adding a new data source, or debugging missing plugin data in the WorldWideView project. Triggers on seeder creation, WebSocket streaming issues, plugin registration failures, manifest validation errors, GeoEntity rendering problems, or data engine integration

WorldWideView Plugin Creation

Overview

A WorldWideView plugin is a self-contained data source that renders geospatial entities on a 3D Cesium globe. Every plugin implements the WorldPlugin interface from the SDK and connects to the V2 Data Engine (Fastify + Redis) that streams live data over WebSocket.

Core principle: Plugins are code bundles. The engine pushes data. The frontend renders it. There is no REST polling between frontend and engine — only WebSocket streaming.

When to Use

• Creating a new data layer plugin (any architecture)
• Building a new seeder in the data engine
• Plugin data doesn't appear on the globe
• WebSocket subscription or split-routing issues
• Build failures after adding a plugin package
• Debugging renderEntity or entity clipping artifacts
• Marketplace plugin installation/validation issues

Do NOT use for:

• Modifying globe rendering primitives → see cesium-rendering rule
• Zustand state management → see state-management rule
• Prisma schema changes → see database-migrations rule
• Monorepo/pnpm workspace issues → see monorepo-workflow rule

Architecture Decision

Does it need live external API data?
├── NO  → Static GeoJSON plugin (wwvStaticCompiler in vite.config.ts)
│         No seeder needed. Place data in data/data.json.
└── YES → Does it update more often than every 30s?
          ├── NO  → Cron Seeder (engine, registerSeeder with cron string)
          │         getPollingInterval() = 0, mapWebsocketPayload() required
          └── YES → Init Seeder (engine, registerSeeder with init function)
                    getPollingInterval() = 0, mapWebsocketPayload() required

---

Quick Reference

Piece	Location	Purpose
Sandbox plugin	local-plugins/wwv-plugin-<name>/	Local development workspace for new plugins
Plugin class	packages/wwv-plugin-<name>/src/index.ts	Implements WorldPlugin interface
Package metadata	packages/wwv-plugin-<name>/package.json	worldwideview block with id, type, format, category
Engine seeder	wwv-seeders/src/seeders/<name>.ts	Fetches external data → Redis → WS broadcast
Build config	next.config.ts → transpilePackages	Required for monorepo packages
TS alias	tsconfig.json → paths	Required for monorepo packages
Registration	src/core/plugins/PluginRegistry.ts	Register plugin at boot
WS client	src/core/data/WsClient.ts	Client-side WebSocket subscriptions
URL resolution	src/core/data/resolveEngineUrl.ts	Per-plugin local vs cloud routing
Manifest validation	src/core/plugins/validateManifest.ts	Checks required fields for CDN bundles
Host globals	src/core/plugins/hostGlobals.ts	Injects shared deps for CDN plugins

---

Part 1: Frontend Plugin (WorldPlugin)

1.0 Development Workflow (Local Sandbox)

The standard way to develop a new plugin is using the Local Sandbox (local-plugins/ directory). This keeps experimental code out of the main monorepo packages until it is ready for production.

1. Scaffold: Run node packages/wwv-cli/dist/index.js create <name> --local from the project root. This generates a boilerplate plugin in local-plugins/wwv-plugin-<name>.
2. Develop: Run pnpm dev. The built-in file watcher (pnpm dev:plugins) automatically rebuilds and syncs your local plugin to public/plugins-local/ whenever you save a file for instant hot-reloading.
3. Publish (Optional): When stable, you can use node packages/wwv-cli/dist/index.js publish <name> from the project root to publish the plugin to NPM (use the --org <your-org> flag to publish under your own NPM organization instead of @worldwideview). There is no need to 'link' plugins to the core monorepo manually, as the local sandbox runs natively inside the workspace.

1.1 Implement the Interface

Every plugin must implement WorldPlugin from @worldwideview/wwv-plugin-sdk:

import type {
  WorldPlugin, PluginContext, GeoEntity,
  CesiumEntityOptions, TimeRange, LayerConfig, PluginCategory
} from "@worldwideview/wwv-plugin-sdk";
import { Flame } from "lucide-react";
import pkg from "../package.json";

export default class WildfiresPlugin implements WorldPlugin {
  id = "wildfires";
  name = "Wildfires";
  description = "Live wildfire incidents from NASA FIRMS";
  icon = Flame;
  category: PluginCategory = "natural-disaster";
  version = pkg.version;  // NEVER hardcode — always import from package.json

  async initialize(ctx: PluginContext): Promise<void> {
    // Store context for later use (env vars, edition, callbacks)
  }

  destroy(): void {
    // Cleanup timers, WebSocket connections, etc.
  }

  async fetch(timeRange: TimeRange): Promise<GeoEntity[]> {
    // For WS-streamed plugins, return [] — data arrives via WsClient
    return [];
  }

  getPollingInterval(): number {
    return 0; // 0 = no REST polling (WS-only)
  }

  getLayerConfig(): LayerConfig {
    return {
      color: "#ef4444",
      clusterEnabled: true,
      clusterDistance: 50,
      maxEntities: 5000,
    };
  }

  renderEntity(entity: GeoEntity): CesiumEntityOptions {
    return {
      type: "point",
      color: "#ef4444",
      size: 6,
      outlineColor: "#ffffff",
      outlineWidth: 1,
    };
  }
}

1.2 Required vs Optional Methods

Required:

Method	Purpose
initialize(ctx)	Receive PluginContext (env, edition, callbacks)
destroy()	Cleanup on shutdown
fetch(timeRange)	Return entities (REST path). Return [] for WS-only
getPollingInterval()	Polling frequency in ms. Return 0 for WS-only
getLayerConfig()	Layer appearance (color, clustering, max entities)
renderEntity(entity)	Per-entity Cesium rendering options

Optional (but mapWebsocketPayload is REQUIRED for WS-only plugins with object payloads):

Method	Purpose
getServerConfig()	REST/WS endpoint config (apiBasePath, streamUrl)
getSelectionBehavior(entity)	Trail/fly-to on entity click
getFilterDefinitions()	User-facing filter controls
getLegend()	Legend entries for layer panel
getSidebarComponent()	Custom sidebar React component
getDetailComponent()	Custom detail panel for selected entity
getSettingsComponent()	Plugin settings UI
getGlobeComponent()	React component injected into globe view
mapWebsocketPayload(payload, existing)	Required if seeder payload is an object (not a flat array). Transforms raw engine payload → GeoEntity[]. Without it, WsClient drops object payloads silently.
requiresConfiguration(settings)	Return true if plugin needs setup first

1.3 Package Metadata

The package.json must include a worldwideview block:

{
  "name": "@worldwideview/wwv-plugin-wildfires",
  "version": "1.0.0",
  "main": "src/index.ts",
  "worldwideview": {
    "id": "wildfires",
    "type": "data-layer",
    "format": "bundle",
    "category": "natural-disaster",
    "icon": "Flame",
    "capabilities": ["data:own", "globe:overlay"]
  },
  "dependencies": {
    "@worldwideview/wwv-plugin-sdk": "workspace:*"
  }
}

Valid categories (lowercase only): aviation · maritime · military · conflict · natural-disaster · infrastructure · space · cyber · economic · intelligence · custom

Valid capabilities: data:own · data:read:{plugin} · ui:detail-panel · ui:sidebar · ui:toolbar · ui:settings · globe:overlay · globe:camera · storage:read · storage:write · network:fetch

1.4 Rendering Rules

Entity Type	Properties	Notes
"point"	color, size, outlineColor, outlineWidth	Simple colored dots
"billboard"	iconUrl, color, iconScale	SVG/PNG icons
"model"	modelUrl, modelScale, modelMinPixelSize	3D glTF models
"label"	labelText, labelFont, color	Text labels

CRITICAL: NEVER mix point and billboard properties. Using size/outlineWidth on a billboard entity causes GPU clipping artifacts. This is a hard rendering constraint.

Use createSvgIconUrl() from the SDK for billboard icons:

import { createSvgIconUrl } from "@worldwideview/wwv-plugin-sdk";
import { Plane } from "lucide-react";
const iconUrl = createSvgIconUrl(Plane, { color: "#3b82f6" });

1.5 Property Tag Helpers

Use these SDK helpers to wrap property values so the Intel panel renders them richly. Without the tag prefix, the panel falls back to plain text.

import { dtProp, urlProp, imageProp, videoProp } from "@worldwideview/wwv-plugin-sdk";

Helper	Tag format stored	Panel renders as
dtProp(iso)	"datetime:2026-06-01T05:00:00Z"	Expandable row: local time (collapsed), UTC + relative (expanded)
urlProp(href)	"url:https://..."	Clickable link with external icon
imageProp(src)	"image:https://..."	Inline thumbnail
videoProp(href)	"video:https://..."	"Watch" link with play icon

All four helpers return null for empty, null, or undefined input — safe to call unconditionally.

Usage pattern:

properties: {
    // dates — pass ISO 8601 strings
    updated_at: dtProp(item.updated_at ?? null),
    // URLs
    source_url: urlProp(item.url ?? null),
    // images and video
    preview: imageProp(item.image_url ?? null),
    stream: videoProp(item.video_url ?? null),
    // plain values — no helper needed
    name: item.name,
    count: item.count,
}

1.6 Registration (3 Paths)

A. Built-in (monorepo package):

import { pluginRegistry } from "@/core/plugins/PluginRegistry";
import { pluginManager } from "@/core/plugins/PluginManager";
import WildfiresPlugin from "@worldwideview/wwv-plugin-wildfires";

const plugin = new WildfiresPlugin();
pluginRegistry.register(plugin);
await pluginManager.registerPlugin(plugin);

AppShell.tsx iterates pluginRegistry.getAll() at startup.

B. Marketplace (database-installed): InstalledPluginsLoader reads from the installed_plugins PostgreSQL table and calls pluginManager.loadFromManifest(). No code changes needed.

C. Dynamic import (runtime): For user-imported GeoJSON layers, call pluginManager.loadFromManifest(manifest) directly.

1.7 Build Configuration (Core Monorepo Packages Only)

If you decide to manually move a plugin from the local sandbox into the core packages/ directory, you must manually add it to the build pipeline:

Add to next.config.ts:

transpilePackages: [
  "@worldwideview/wwv-plugin-sdk",
  "@worldwideview/wwv-plugin-wildfires", // ADD
],

Add to tsconfig.json:

"paths": {
  "@worldwideview/wwv-plugin-wildfires": ["./packages/wwv-plugin-wildfires/src"]
}

Run pnpm install from project root after creating the package.

---

Part 2: Data Engine Seeder

The data engine is a content-agnostic Host Environment runner (wwv-data-engine, deployed via Docker). It runs Fastify on port 5000 with Redis caching and WebSocket streaming. Seeders are volume-mounted from local-seeders/ (dev) or dynamically downloaded and linked via pnpm workspaces from GitHub Releases (wwv-seeders and wwv-seeders-private) in production.

[!IMPORTANT] If you are migrating an existing plugin from packages/ to local-plugins/, use the migrate-legacy-plugin skill instead. It covers both frontend routing fixes AND backend seeder build fixes as two independent concerns.

2.1 Engine Architecture

External API → Seeder (fetch + transform)
  → setLiveSnapshot(pluginId, payload, ttlSeconds)
    → broadcastPluginData() → Active WS subscribers (immediate)
    → Redis SET data:{pluginId}:live (throttled to every 5 min)
  → SQLite history (optional, via better-sqlite3)

Key components:

• src/scheduler.ts — Seeder registry and cron scheduling
• src/redis.ts — Redis client, setLiveSnapshot() and getLiveSnapshot()
• src/websocket.ts — WS handler, broadcastPluginData()
• src/seed-utils.ts — withRetry(), fetchWithTimeout(), haversineKm()
• src/db.ts — SQLite (better-sqlite3) for local history storage
• src/seeders/index.ts — Auto-discovery, dynamically requires all seeder files

2.2 Two Seeder Patterns

Cron Seeder (periodic polling — most common):

import { db } from "../db";
import { setLiveSnapshot } from "../redis";
import { fetchWithTimeout, withRetry } from "../seed-utils";
import { registerSeeder } from "../scheduler";

// Optional: SQLite history table insert
const insertRow = db.prepare(
  "INSERT OR IGNORE INTO my_data (id, payload, source_ts, fetched_at) VALUES (@id, @payload, @source_ts, @fetched_at)"
);

async function seedMyPlugin() {
  console.log("[MyPlugin] Polling external API...");

  const res = await withRetry(() =>
    fetchWithTimeout("https://api.example.com/data")
  );
  const data = await res.json();

  const items = data.features.map((f: any) => ({
    id: f.id,
    lat: f.geometry.coordinates[1],
    lon: f.geometry.coordinates[0],
    name: f.properties.name,
    // ... transform to your schema
  }));

  // Optional: save to SQLite
  for (const item of items) {
    insertRow.run({
      id: item.id,
      payload: JSON.stringify(item),
      source_ts: Date.now(),
      fetched_at: Date.now(),
    });
  }

  // REQUIRED: Push to Redis + broadcast to WS subscribers
  await setLiveSnapshot("my-plugin", {
    source: "my-plugin",
    fetchedAt: new Date().toISOString(),
    items,
    totalCount: items.length,
  }, 3600); // TTL in seconds
}

registerSeeder({
  name: "my-plugin",       // MUST match the plugin's id on the frontend
  cron: "*/15 * * * *",   // Every 15 minutes
  fn: seedMyPlugin,
});

Init Seeder (persistent/high-frequency — e.g., ISS every 5s):

import { setLiveSnapshot } from "../redis";
import { registerSeeder } from "../scheduler";

function startMySeeder() {
  console.log("[MyPlugin] Starting persistent seeder...");

  async function poll() {
    const res = await fetch("https://api.example.com/live");
    const data = await res.json();
    await setLiveSnapshot("my-plugin", data, 60);
  }

  poll(); // Initial fetch
  setInterval(poll, 5000); // Every 5 seconds
}

registerSeeder({
  name: "my-plugin",
  init: startMySeeder,  // No cron — uses init for persistent polling
});

2.3 SeederDefinition Interface

interface SeederDefinition {
  name: string;          // Plugin ID — MUST match frontend plugin id
  cron?: string;         // Cron expression (e.g., "0 * * * *" = hourly)
  fn?: () => Promise<void>;  // Function called on each cron tick
  init?: () => void;     // Initialization for persistent seeders (websockets, intervals)
}

2.4 Auto-Discovery & Dependencies

The V2 engine dynamically import()s every compiled .mjs file in the extracted seeder workspaces. You do not need to manually import your seeder — just create the file and call registerSeeder() at module scope.

[!IMPORTANT] V2 Engine Dependencies: Seeders run in the unified V2 host environment which provides common packages (zod, ws, undici, etc.). You MUST NOT bundle these dependencies in your seeder's dist folder. Leave them externalized in your build config.

2.5 SQLite History (Optional)

For data that benefits from historical queries (playback mode), add a table in src/db.ts:

db.exec(`
  CREATE TABLE IF NOT EXISTS my_data (
    id TEXT PRIMARY KEY,
    payload JSON NOT NULL,
    source_ts INTEGER NOT NULL,
    fetched_at INTEGER NOT NULL
  )
`);

2.6 Utility Functions

Function	Purpose
withRetry(fn, maxRetries, delayMs)	Exponential backoff retry wrapper
fetchWithTimeout(url, options, timeoutMs)	Fetch with abort signal (default 15s)
haversineKm(lat1, lon1, lat2, lon2)	Distance between coordinates in km
sleep(ms)	Promise-based delay
CHROME_UA	Chrome User-Agent string for scraping

---

Part 3: Data Pipeline (Frontend ↔ Engine)

3.1 WebSocket Protocol

Client → Engine:

{ "action": "subscribe", "pluginId": "earthquakes" }
{ "action": "unsubscribe", "pluginId": "earthquakes" }

Engine → Client:

{ "type": "welcome", "engine": "wwv-data-engine-v2", "plugins": ["earthquakes", "wildfires", ...] }
{ "type": "data", "pluginId": "earthquakes", "payload": { "items": [...], "totalCount": 42 } }

On subscribe, the engine immediately pushes the latest cached Redis snapshot — no waiting for the next cron tick.

3.2 Split-Routing (resolveEngineUrl)

resolveEngineUrl(pluginId) determines which engine serves each plugin:

1. Local engine (localhost:5000) if running and its /manifest includes this plugin ← HIGHEST PRIORITY
2. Plugin's getServerConfig().streamUrl (code override)
3. Plugin's PluginManifest.dataSource.streamUrl (manifest override)
4. NEXT_PUBLIC_WWV_PLUGIN_DATA_ENGINE_URL env var
5. Fallback: wss://dataenginev2.worldwideview.dev/stream (cloud)

3.3 Full Data Flow

Engine seeder calls setLiveSnapshot(pluginId, payload, ttl)
  → broadcastPluginData() fans out to subscribed WS connections
  → WsClient receives { type: "data", pluginId, payload }
  → WsClient calls plugin.mapWebsocketPayload() if defined
  → DataBus.emit("dataUpdated", { pluginId, entities })
  → DataBusSubscriber → Zustand store.entitiesByPlugin
  → GlobeView (memoized visible entities)
  → EntityRenderer (billboard/point/label primitives)

3.4 Host Globals (CDN Plugins)

CDN-loaded plugins share the host app's dependencies via globalThis.__WWV_HOST__:

• react, react-dom, react/jsx-runtime
• cesium, resium
• zustand
• @worldwideview/wwv-plugin-sdk

Use wwvPluginGlobals() in your Vite config to externalize automatically:

import { defineConfig } from "vite";
import { wwvPluginGlobals } from "@worldwideview/wwv-plugin-sdk";

export default defineConfig({
  plugins: [wwvPluginGlobals()],
  build: {
    lib: { entry: "./src/index.ts", formats: ["es"], fileName: "frontend" },
    rollupOptions: { output: { entryFileNames: "frontend.mjs" } },
  },
});

---

Part 4: Static GeoJSON Plugins

For plugins with static data (no live API), use wwvStaticCompiler:

import { defineConfig } from "vite";
import { wwvPluginGlobals, wwvStaticCompiler } from "@worldwideview/wwv-plugin-sdk";

export default defineConfig({
  plugins: [wwvStaticCompiler(), wwvPluginGlobals()],
  build: {
    lib: { entry: "./src/index.ts", formats: ["es"], fileName: "frontend" },
  },
});

Place GeoJSON in data/data.json. The compiler auto-generates a WorldPlugin class from package.json metadata at build time. No src/index.ts needed.

---

Part 5: Example - Simple ISS Tracker Plugin

Here is a minimal, complete example of a live ISS Tracker plugin utilizing both the frontend SDK and the V2 Engine.

1. Frontend Plugin (local-plugins/wwv-plugin-iss/src/index.ts)

import type {
  WorldPlugin, PluginContext, GeoEntity,
  CesiumEntityOptions, TimeRange, LayerConfig, PluginCategory
} from "@worldwideview/wwv-plugin-sdk";
import { Satellite } from "lucide-react";
import pkg from "../package.json";

export default class IssPlugin implements WorldPlugin {
  id = "iss";
  name = "ISS Tracker";
  description = "Real-time International Space Station tracking";
  icon = Satellite;
  category: PluginCategory = "space";
  version = pkg.version;

  async initialize(ctx: PluginContext): Promise<void> {}

  destroy(): void {}

  async fetch(_timeRange: TimeRange): Promise<GeoEntity[]> {
    return []; // WS-only — data arrives via mapWebsocketPayload
  }

  getPollingInterval(): number {
    return 0; // WS-only
  }

  // REQUIRED: seeder sends { source, fetchedAt, items: [...], totalCount } (an object).
  // Without this, WsClient drops the payload silently — the globe stays empty.
  mapWebsocketPayload(payload: any, _existingEntities: GeoEntity[]): GeoEntity[] {
    const items: any[] = payload?.items ?? (Array.isArray(payload) ? payload : []);
    return items.map((item: any): GeoEntity => ({
      id: `iss-${item.id}`,
      pluginId: "iss",
      latitude: item.lat,
      longitude: item.lon,
      altitude: item.alt ?? 0,
      timestamp: new Date(),
      label: "International Space Station",
      properties: { speed: item.speed },
    }));
  }

  getLayerConfig(): LayerConfig {
    return {
      color: "#ffffff",
      clusterEnabled: false,
      maxEntities: 1,
    };
  }

  renderEntity(entity: GeoEntity): CesiumEntityOptions {
    return {
      type: "point",
      color: "#ffffff",
      size: 10,
      outlineColor: "#3b82f6",
      outlineWidth: 2,
    };
  }
}

2. Backend Init Seeder (wwv-seeders/src/seeders/iss.ts)

import { setLiveSnapshot } from "../redis";
import { registerSeeder } from "../scheduler";

function startIssSeeder() {
  console.log("[ISS] Starting live tracker...");

  async function poll() {
    try {
      const res = await fetch("https://api.wheretheiss.at/v1/satellites/25544");
      const data = await res.json();

      const item = {
        id: "iss",
        lat: data.latitude,
        lon: data.longitude,
        alt: data.altitude * 1000, // Convert km to meters
        name: "International Space Station",
        speed: data.velocity,
      };

      await setLiveSnapshot("iss", {
        source: "iss",
        fetchedAt: new Date().toISOString(),
        items: [item],
        totalCount: 1,
      }, 10);
    } catch (err) {
      console.error("[ISS] Fetch failed", err);
    }
  }

  poll(); // Initial fetch
  setInterval(poll, 5000); // Poll every 5 seconds
}

registerSeeder({
  name: "iss",
  init: startIssSeeder,
});

---

Common Mistakes

"Sandbox Plugin Breaking Next.js Build"

1. Premature Configuration — Modifying next.config.ts (transpilePackages) or tsconfig.json (paths) while a plugin is still in local-plugins/. The local-plugins sandbox relies on dynamic hot-loading in the browser via pnpm dev:plugins. Do not touch monorepo configs for local plugins.
2. Manual Registration — Manually adding a sandbox plugin to AppShell.tsx. Let the local hot-loading manifest handle sandbox plugins dynamically.

"Missing Boilerplate / Errors in package.json"

1. Bypassing the CLI — Creating a plugin manually instead of using node packages/wwv-cli/dist/index.js create <name> --local. Always use the CLI to ensure the correct metadata, type definitions, and test scaffolding are generated.

"No data on the globe"

1. Seeder name ≠ plugin id — The name in registerSeeder() MUST match the id property of the frontend WorldPlugin class
2. Engine /manifest missing plugin — Check GET localhost:5000/manifest → plugins array
3. WsClient not subscribing — Add console.log in resolveEngineUrl() to verify URL resolution
4. Plugin hardcodes engine URL — Legacy plugins use this.context?.apiBaseUrl instead of resolveEngineUrl(). See migrate-legacy-plugin skill
5. mapWebsocketPayload missing — If the engine sends a non-standard payload shape, the plugin must implement mapWebsocketPayload() or data silently drops

"Build crash / Module not found"

1. Missing transpilePackages entry in next.config.ts → immediate runtime crash
2. Missing tsconfig.json path alias → TypeScript compilation error
3. Forgot pnpm install after creating package → dependency resolution failure

"Invalid Hook Call" (CDN plugins)

Plugin bundles its own React instead of using host globals. Fix: add wwvPluginGlobals() to Vite config.

"Manifest validation failed"

Required fields: id, name, version, entry, trust. Entry URL must be from allowed domains (CDN, localhost, worldwideview.dev, or relative path). capabilities must be non-empty array.

"GPU clipping / entity disappearing"

Using size/outlineWidth/outlineColor on a "billboard" entity. These properties are point-only. Billboard uses iconUrl/iconScale/color.

"Redis snapshot not updating"

setLiveSnapshot() throttles Redis writes to every 5 minutes to avoid exceeding Upstash request limits. WebSocket broadcasts are not throttled. Check WS delivery first.

"Category type error"

Categories are lowercase: "aviation" not "Aviation", "natural-disaster" not "NaturalDisaster". Must match the PluginCategory union in the SDK.

---

End-to-End Checklist

• Development: Scaffolded via node packages/wwv-cli/dist/index.js create and developed in local-plugins/
• Publishing: Published to NPM via node packages/wwv-cli/dist/index.js publish <name> [--org <your-org>] (if making public)
• Frontend: Plugin class implements WorldPlugin with correct id
• Frontend: package.json has worldwideview block with matching id
• Frontend: Version imported from package.json (never hardcoded)
• Frontend: Added to transpilePackages in next.config.ts
• Frontend: Added path alias in tsconfig.json
• Frontend: Registered via pluginRegistry + pluginManager in AppShell.tsx
• Frontend: renderEntity() doesn't mix point/billboard properties
• Frontend: Date/time fields wrapped with dtProp()
• Frontend: External links wrapped with urlProp()
• Frontend: Image URLs wrapped with imageProp()
• Frontend: Video/stream URLs wrapped with videoProp()
• Engine: Seeder file in wwv-seeders/src/seeders/<name>.ts (or private repo)
• Engine: registerSeeder({ name }) matches frontend plugin id
• Engine: Calls setLiveSnapshot() with correct plugin ID key
• Engine: Seeder payload is either a flat GeoEntity[] array OR plugin implements mapWebsocketPayload (any other object is silently dropped by WsClient)
• Frontend (WS-only): getPollingInterval() returns 0 and fetch() returns []
• Frontend (WS-only): mapWebsocketPayload(payload, existingEntities) implemented if seeder sends an object
• Engine: SQLite table created in db.ts if historical data needed
• Verification: GET localhost:5000/manifest includes the plugin ID
• Verification: GET localhost:5000/health shows seeder last-run timestamp
• Verification: WebSocket subscribe returns data snapshot
• Workspace: Ran pnpm install from project root
• Workspace: Version bump follows /commit workflow