/nano-banana-image-ad

name: nano-banana-image-ad
description: >-
  Generate one or more standalone Meta image-ad creatives via Nano Banana 2 / Nano Banana Pro (Gemini Flash Image family) through the Arcads external API. Locks the model family, auto-strips platform chrome, enforces edge-safe layouts. Use when the user asks for a "Nano Banana ad", "Gemini image ad", "nano-banana-2 ad creative", "make a static image ad with Gemini", or anchors on a need for photoreal / lifestyle / multi-reference / handheld-object / clay-texture ad creatives (sticky-note flatlays, held-whiteboard signs, lifestyle portraits, ingredient collages, OOH photography). Does NOT trigger on ChatGPT Image cues — use chatgpt-image-ad for those.

nano-banana-image-ad (Arcads)

Generate one or more **standalone Meta ad image creatives** via Arcads' `POST /v2/images/generate` with the Nano Banana model family (default `nano-banana-2`). Hands the image paths off to your Meta-ad-builder skill — this skill does not upload to Meta itself.

Read order

1. **This file** — Arcads-specific endpoint, auth, presigned upload flow, workflow phases. 2. **[shared/skills/nano-banana-image-ad/prompting/guide.md](../../shared/skills/nano-banana-image-ad/prompting/guide.md)** — model-specific prompting (what Nano Banana is good/bad at, when to switch to gpt-image-2). 3. **[shared/skills/image-ad-prompting/prompting/prompt-library.md](../../shared/skills/image-ad-prompting/prompting/prompt-library.md)** — 30+ validated templates with per-model notes. 4. **[shared/skills/image-ad-prompting/prompting/safety-suffixes.md](../../shared/skills/image-ad-prompting/prompting/safety-suffixes.md)** — the 3 always-on guards. 5. **[scripts/generate_image.py](scripts/generate_image.py)** — the helper script (Python stdlib only).

Hard rules — never relax

1. **Model is in the Nano Banana family.** The script accepts `nano-banana-2` (default), `nano-banana-pro` (Gemini 3 Pro Image, higher cost / locked identity), `nano-banana-edit` (inpaint-focused), or `nano-banana` (legacy). Anything else is refused. If the user asks for gpt-image-2, point them at `chatgpt-image-ad`. 2. **No platform/screenshot chrome in output.** `NO_CHROME_SUFFIX` is always on (override only with `--allow-chrome`). 3. **Edge-safe + glyph-safety suffixes always on** unless `--no-safe-zone` is explicit. 4. **Max 14 reference images.** Hard Arcads cap for Nano Banana. Script enforces. 5. **No Meta upload from this skill.** Image generation only. The user has a separate ad-builder skill in their stack — hand off via filesystem paths. 6. **Always present a credit-cost estimate before generating.** Each Nano Banana call is one image; multiply by `--n`. `nano-banana-pro` costs more than `nano-banana-2` — surface the per-model rate from `logs/arcads-api.jsonl`.

Prerequisites

• `.env` containing `ARCADS_BASIC_AUTH` (preferred) OR `ARCADS_API_KEY`
• Optional: `PRODUCT_ID`, `PROJECT_ID` in `.env` for session-folder organization
• Reference images on local disk. The script handles the Arcads presigned-upload flow internally.

Configuration

• **Base URL:** `https://external-api.arcads.ai` (or `ARCADS_BASE_URL`).
• **Auth:** HTTP Basic. The script prefers a pre-encoded `ARCADS_BASIC_AUTH`; falls back to encoding `ARCADS_API_KEY`.
• **Endpoint:** `POST /v2/images/generate`; poll `GET /v1/assets/{id}` until `status: generated`.
• **Reference uploads:** `POST /v1/file-upload/get-presigned-url` returns `{presignedUrl, filePath}`; `PUT` bytes to `presignedUrl`; pass the `filePath` in `referenceImages`. Single-use — re-uploaded fresh per variant by the script.

Generation modes

| Mode | When to use | Required | Optional | |---|---|---|---| | `image` (default) | Brand-new ad image. | `--prompt`, `--aspect-ratio` | `--image-ref` (up to 14) | | `image_edit` | Modify a `--source` image. | `--prompt`, `--source` | `--image-ref` (up to 14) |

Supported aspect ratios

`1:1`, `16:9`, `9:16`. **Only these three are accepted by Arcads' `/v2/images/generate` endpoint** (the same endpoint serves gpt-image-2 and Nano Banana — same ratio constraints). Templates in the shared library that use `2:3`, `4:5`, `3:2`, etc. won't render at their native ratio on this backend — fall back to `1:1` and post-crop, or use the KIE nano-banana-image-ad sibling which supports the full Meta ratio set natively via the `/jobs/createTask` endpoint.

Model variants (`--model`)

• **`nano-banana-2`** (default) — Gemini 2.5 Flash Image. The standard. Use for most templates.
• **`nano-banana-pro`** — Gemini 3 Pro Image. Use for hero stills, character continuity across runs, material-realism critical shots (claymation, Pixar, premium product photography). Costs more credits.
• **`nano-banana-edit`** — inpaint-focused. Use only with `--mode image_edit` for tight masked edits (swap background, change object color).
• **`nano-banana`** — legacy. Use only if the user explicitly asks; new work should use `nano-banana-2`.

Ask the user which variant they want **before the first generation in a session** if the value isn't already set in `MASTER_CONTEXT.md`. Default to `nano-banana-2`.

Workflow

Phase 1: Preflight

1. `.env` exists with credentials. 2. (Optional) `arcads-external-api` session folder set up. 3. Health-check: `curl -sf -H "$AUTH" "$BASE_URL/v1/products"` returns 200.

Phase 2: Gather inputs

Collect: seed prompt, mode, source (if edit), reference paths (up to 14), variant count, aspect ratio, model variant.

Phase 3: Prompt rewrite

Read [shared/skills/image-ad-prompting/prompting/prompt-library.md](../../shared/skills/image-ad-prompting/prompting/prompt-library.md). If the user's brief matches a template, **check the Model notes block** — only proceed if `nano-banana` is marked clean, preferred, or strong. If gpt-image-2 is preferred, suggest switching skills.

Fill `{placeholders}` and show the user the rewritten prompt. Ask for approval before generating.

For fresh prompts (no template match), follow