Add SceneSeed prompt-to-object canvas plugin

apps/server/src/services/plugins/builtin-registry.ts

@@ -192,6 +192,12 @@ export const OFFICIAL_PLUGINS = [
     defaultEnabled: true,
     category: "Workflow management",
   },
+  {
+    name: "sceneseed",
+    pluginId: "sceneseed",
+    defaultEnabled: true,
+    category: "Interface",
+  },
 ].map(
   (plugin): BundledPluginDefinition => ({
     ...plugin,

apps/server/src/services/skills/builtin-skills/bb-cli/SKILL.md

@@ -785,7 +785,7 @@ them by mixing ink into canvas), the `--primary` accent, the secondary text tier
   (except `side-chat`, which is gated by the **"Side chat plugin"**
   experiment); official plugins install from the bundled store on demand.
 - **BB Official plugins** (store under `/api/v1/plugin-catalog`):
-  - BB's official plugins (GitHub, Docs, Memory, and Tasks) ship
+  - BB's official plugins (GitHub, Docs, Memory, Tasks, and SceneSeed) ship
     bundled inside the app and install from the local copy — no network. Installed official
     plugins are pinned to the bundled copy and update with BB app releases.
   - The store also lists the **BB Community marketplace** catalog: a manifest

apps/server/test/services/plugins/builtin-plugins.test.ts

@@ -213,7 +213,13 @@ describe("builtin plugin reconciliation", () => {
 
   it("keeps official plugins bundled but out of the auto-install builtins", () => {
     const optionalNames = OFFICIAL_PLUGINS.map((plugin) => plugin.name);
-    expect(optionalNames).toEqual(["github", "docs", "memory", "tasks"]);
+    expect(optionalNames).toEqual([
+      "github",
+      "docs",
+      "memory",
+      "tasks",
+      "sceneseed",
+    ]);
     for (const name of optionalNames) {
       expect(BUILTIN_PLUGINS.map((plugin) => plugin.name)).not.toContain(name);
     }

apps/server/test/services/plugins/official-plugins.test.ts

@@ -108,6 +108,7 @@ describe("official plugin registry invariants", () => {
       "provider-codex": "Agent interaction",
       "provider-pi": "Agent interaction",
       "provider-retry": "Agent interaction",
+      sceneseed: "Interface",
       secrets: "Developer tools",
       "side-chat": "Agent interaction",
       tasks: "Workflow management",

docs/configuration.md

@@ -705,7 +705,7 @@ Plugin state lives under the data dir:
                                    commands, injected into agent threads)
 ```
 
-BB's official plugins (GitHub, Docs, Memory, and Tasks) ship bundled
+BB's official plugins (GitHub, Docs, Memory, Tasks, and SceneSeed) ship bundled
 inside the app and install from the local bundled copy — no network, no remote catalog.
 Discover them with `bb plugin search` or Extensions → Plugins → Browse; users
 cannot add, remove, or configure the bundled official plugin set. Installed official

docs/official-plugin-release-process.md

@@ -15,12 +15,13 @@ until a user installs them.
 
 The official plugins are:
 
-| Directory        | Package name             | Store entry | Plugin id      |
-| ---------------- | ------------------------ | ----------- | -------------- |
-| `plugins/github` | `bb-plugin-github`       | `github`    | `github`       |
-| `plugins/docs`   | `bb-plugin-simple-notes` | `docs`      | `simple-notes` |
-| `plugins/memory` | `bb-plugin-memory`       | `memory`    | `memory`       |
-| `plugins/tasks`  | `bb-plugin-tasks`        | `tasks`     | `tasks`        |
+| Directory           | Package name             | Store entry | Plugin id      |
+| ------------------- | ------------------------ | ----------- | -------------- |
+| `plugins/github`    | `bb-plugin-github`       | `github`    | `github`       |
+| `plugins/docs`      | `bb-plugin-simple-notes` | `docs`      | `simple-notes` |
+| `plugins/memory`    | `bb-plugin-memory`       | `memory`    | `memory`       |
+| `plugins/tasks`     | `bb-plugin-tasks`        | `tasks`     | `tasks`        |
+| `plugins/sceneseed` | `bb-plugin-sceneseed`    | `sceneseed` | `sceneseed`    |
 
 ## Releasing a change
 

packages/templates/src/templates/bb-guide-plugins.md

@@ -159,6 +159,22 @@ label-link/name change, active-thread change, or project-prefix change invalidat
 outstanding cursor; restart without `--cursor` instead of accepting a mixed
 snapshot.
 
+The SceneSeed plugin is an opt-in official plugin bundled with the app:
+`bb plugin install sceneseed`. It turns prompt cards into bounded, dimensional
+scenes and exposes the same durable canvases to agents through its CLI:
+
+  bb sceneseed list
+  bb sceneseed show <canvas-id> --json
+  bb sceneseed add <canvas-id> --prompt <text> [--x <number>] [--y <number>]
+  bb sceneseed wait <job-id>
+  bb sceneseed cancel <job-id>
+  bb sceneseed remove-object <canvas-id> <object-id>
+
+SceneSeed stores prompts, scene graphs, transforms, and job state in its
+private plugin database. Generated scenes cannot contain executable code,
+URLs, files, remote assets, or shaders. Use **Delete all canvas data** in its
+settings to archive its hidden canvas threads and erase the stored canvases.
+
 The builtin Secrets plugin provides a secure credential form and guarded
 dotenv reconciliation:
 
@@ -174,7 +190,7 @@ added/updated/unchanged counts.
                                  the app plus every registered marketplace
                                  catalog
   bb plugin install <entry>      Install a bundled official plugin by name
-                                 (github, docs, memory, tasks),
+                                 (github, docs, memory, tasks, sceneseed),
                                  <entry-id>@<marketplace>, a Git repository
                                  URL, local path, builtin:<name>,
                                  git:<url>[@<ref|semver-range>], or
@@ -331,13 +347,14 @@ rollback, and remove keep working per plugin.
 
 BB Official plugins
 
-BB's official plugins — GitHub, Docs, Memory, and Tasks — ship bundled inside
-the app itself. They appear in Extensions → Plugins → Browse
+BB's official plugins — GitHub, Docs, Memory, Tasks, and SceneSeed — ship
+bundled inside the app itself. They appear in Extensions → Plugins → Browse
 and install with one click from the local bundled copy: no network, no
 download, no separate release. Install from the CLI by bare name
 (`bb plugin install github`, `bb plugin install docs`, `bb plugin install
-memory`, or `bb plugin install tasks`). Installed official plugins are pinned
-to the bundled copy and update automatically when the BB app updates.
+memory`, `bb plugin install tasks`, or `bb plugin install sceneseed`). Installed
+official plugins are pinned to the bundled copy and update automatically when
+the BB app updates.
 
 The BB Community marketplace (reserved name `bb-community`) lists reviewed
 plugins that live outside the app bundle. bb reads its manifest from
@@ -776,9 +793,9 @@ in a checkout). The builtin `inline-vis` plugin renders
 path-shaped, sandboxed worktree HTML iframe preview; `height` is optional.
 Its card header includes an open-in-sidebar action for the source HTML file.
 The `plugins/` directory contains every bundled plugin: the auto-installed
-builtins and the store-only BB Official GitHub, Docs, Memory, and Tasks
-plugins. The `examples/plugins/` reference plugins cover slack-bot (webhook
-bot), agent-enrichment (agent surfaces), and composer-customization (all
+builtins and the store-only BB Official GitHub, Docs, Memory, Tasks, and
+SceneSeed plugins. The `examples/plugins/` reference plugins cover slack-bot
+(webhook bot), agent-enrichment (agent surfaces), and composer-customization (all
 composer regions). Thread Hover
 Cards installs from the BB Community marketplace (source: the bb-plugins
 repo).

plugins/sceneseed/README.md

@@ -0,0 +1,62 @@
+# SceneSeed
+
+SceneSeed is bb's playful prompt-to-object canvas. Write a short prompt on a
+card, place it on the stage, and a hidden bb agent interprets it as a bounded,
+dimensional Three.js scene.
+
+## Install
+
+Install SceneSeed from the BB Official catalog:
+
+```bash
+bb plugin install sceneseed
+```
+
+Open **SceneSeed** in bb's navigation, acknowledge the first-run disclosure,
+create a canvas, and place a prompt card. Dragging is optional: every ready card
+also has a keyboard-accessible **Place on canvas** action.
+
+## Agent access
+
+The same saved records are available through the plugin CLI:
+
+```bash
+bb sceneseed list
+bb sceneseed show <canvas-id> --json
+bb sceneseed add <canvas-id> --prompt "a storm in a teacup" --x 0 --y 0
+bb sceneseed wait <job-id>
+bb sceneseed cancel <job-id>
+bb sceneseed remove-object <canvas-id> <object-id>
+```
+
+## Safety and privacy
+
+- Generated output must conform to SceneSeed's strict, versioned scene contract.
+  It cannot contain executable code, URLs, files, remote assets, or shaders.
+- Prompts, generated scene graphs, transforms, job state, and canvas metadata are
+  stored in the plugin's private SQLite database, not in a project workspace.
+- Each canvas uses a hidden, persistent bb thread in the personal project. The
+  thread uses the normal provider and bb capability envelope; SceneSeed asks it
+  not to inspect unrelated context, but does not claim structural isolation.
+- Disabling or uninstalling the plugin does not erase its database or spawned
+  threads. Use **Delete all canvas data** in SceneSeed settings to archive canvas
+  threads and clear the stored canvases.
+
+## MVP limits
+
+A canvas accepts at most 12 cards in flight, 25 active objects, and 100 active
+scene-cost units. Jobs run serially per canvas. Sharing, export, collaboration,
+raw mesh editing, remote model loading, and image generation are intentionally
+out of scope.
+
+`fixtures/prompt-scenes.json` is the fixed 32-prompt evaluation set for future
+agent-quality runs: eight literal, metaphorical, spatial, and abstract prompts,
+each with nearby-scene context and observable interpretation cues. It is test
+data, not bundled executable content.
+
+## Develop
+
+```bash
+pnpm exec turbo run test typecheck build --filter=bb-plugin-sceneseed
+bb plugin dev ./plugins/sceneseed
+```