comic-storyboard-b2

Describe a story in a sentence or two and get back a multi-panel comic / storyboard whose characters and settings stay consistent across panels — every generated frame persisted durably to Backblaze B2 with a SHA-256 provenance manifest.

This is a cheap generative-media sample for developers evaluating Genblaze. The point is ergonomics: the entire generate-and-persist surface is a single Pipeline(...).step(...).run(sink=...) chain. B2 storage, content-addressing, SHA-256 manifests, fan-out concurrency, and variant lineage all come from the library — not from sample code.

Storage is delegated end to end: this sample contains zero direct S3/boto3 calls. Everything lands in B2 through genblaze-s3's ObjectStorageSink, which owns the only S3 client (and sets its own b2ai-genblaze/<version> user agent). Per-app identity is carried in Pipeline(name="comic-storyboard-b2") and written into every manifest.

New to Backblaze B2 Cloud Storage? Start here: https://blze.ai/storage

What it looks like

Generate Panels View

What it does

1. LLM story breaker — one sentence → a structured PanelScript (a hero character + per-panel prompts) via Claude with forced-schema tool use.
2. Character reference sheet — generated once (FLUX-schnell), persisted on B2, and reused as the consistency anchor for every panel.
3. Character-consistent panels — fofr/consistent-character via genblaze-replicate, fanned out concurrently with input_from=0 + max_concurrency.
4. Panel variants with lineage — from_result() regenerates a single panel as a child run carrying parent_run_id, persisted on B2.
5. Export as image strip — panels composed into one downloadable PNG, fetched from their durable public B2 URLs.
6. Provenance built in — every asset carries a SHA-256 manifest from Genblaze; no sample code involved.

Architecture at a glance

Next.js (apps/web)  ──HTTP──▶  FastAPI (services/api)
                                  │
                                  ├─ story_breaker.py   Claude → PanelScript   (one non-Genblaze AI call)
                                  ├─ repo/pipelines.py  Pipeline.step().run()  (ALL genblaze_* lives here)
                                  └─ repo/storage.py    S3StorageBackend.for_backblaze → ObjectStorageSink
                                                                │
                                                                ▼
                                                         Backblaze B2 (assets + manifests)

See docs/ARCHITECTURE.md for the full data flow and docs/app-workflows.md for the API call sequence.

Quickstart

1. Configure

cp .env.example .env
# fill in B2_*, REPLICATE_API_TOKEN, ANTHROPIC_API_KEY

The B2 application key needs readFiles + writeFiles on the target bucket. The bucket must be public so the strip exporter can fetch durable panel URLs.

2. Backend (FastAPI + Genblaze)

cd services/api
uv venv --python 3.11
uv pip install -r requirements.txt        # installs genblaze-* from PyPI
uv run uvicorn app.main:app --reload      # http://localhost:8000

3. Frontend (Next.js)

cd apps/web
npm install
npm run dev                               # http://localhost:3000

Open http://localhost:3000, type a story idea, pick a panel count, and generate. Re-roll any panel for a lineage-tracked variant, then export the strip.

The prompt → strip flow

idea ──▶ break_story()        Claude, forced-schema tool use → PanelScript
     ──▶ build_comic()        step 0: hero ref sheet; steps 1..N: panels (input_from=0, fan-out)
     ──▶ .run(sink=...)       assets + SHA-256 manifest persisted to B2, returns (Run, Manifest)
     ──▶ regenerate_panel()   from_result() → child run with parent_run_id (variant)
     ──▶ compose_strip()      Pillow tiles the durable B2 URLs into one PNG download

Tech

• Backend: FastAPI, genblaze-core, genblaze-s3, genblaze-replicate, anthropic, Pillow. Python 3.11+.
• Frontend: Next.js 16 (App Router), React 19, Tailwind v4, shadcn/ui.

Credits

The visual design system (Tailwind theme tokens and shadcn primitives under apps/web/src/components/ui/) is imported from the internal vibe-coding-starter-kit; only style tokens and UI primitives were copied — no pages, routes, or business logic.