nano-banana-2
agentspace-so/runcomfy-agent-skills
Generate images with Google Nano Banana 2 (Gemini flash-tier) via RunComfy CLI — optimized prompting patterns included.
What is nano-banana-2?
Nano Banana 2 is a flash-tier text-to-image skill that calls Google's Gemini-family image model through the RunComfy CLI. It bundles documented prompting patterns for sharper output, supports batch generation (up to 4 images), multiple aspect ratios and resolution tiers (0.5K–4K), in-image typography, optional web-grounded context, and a safety-tolerance dial. Best suited for rapid ideation, social thumbnails, and poster/card assets with quoted text rendering.
- Runs `google/nano-banana-2/text-to-image` via the local RunComfy CLI
- Supports 1–4 images per request across 11 aspect ratios and 4 resolution tiers
- Renders in-image typography predictably when text is explicitly quoted in the prompt
- Optionally grounds generation in current web context via `enable_web_search`
- Locks composition across prompt variants using a seed parameter
- Documents when to route to sibling models (Nano Banana Pro, GPT Image 2, Flux 2, Seedream)
How to install nano-banana-2
npx skills add https://github.com/agentspace-so/runcomfy-agent-skills --skill nano-banana-2- Node.js available to run `npx`
- RunComfy CLI installed: `npm i -g @runcomfy/cli`
- RunComfy account created at runcomfy.com
- Authenticated via `runcomfy login` (browser device-code flow)
- For CI/containers: `RUNCOMFY_TOKEN=<token>` environment variable set instead of login
How to use nano-banana-2
- 1.Install the skill: `npx skills add https://github.com/agentspace-so/runcomfy-agent-skills --skill nano-banana-2`
- 2.Ensure RunComfy CLI is installed and you are logged in (`runcomfy login`)
- 3.Run a default 1K square draft: `runcomfy run google/nano-banana-2/text-to-image --input '{"prompt": "<your prompt>"}' --output-dir <path>`
- 4.For ideation batches, set `num_images: 4`, `resolution: "0.5K"`, and desired `aspect_ratio`
- 5.Lock `seed` when iterating small prompt variants to keep composition stable
- 6.Quote in-image text literally in the prompt and specify placement and font style
- 7.Enable `enable_web_search: true` only when the prompt references current events or real entities
- 8.Check exit codes (0 = success, 75 = retryable timeout/429, 77 = auth failure) for error handling
Use cases
- Batch ideation drafts (4-up at 0.5K, promote winner to 2K)
- Social-platform thumbnails in native aspect ratios (9:16, 4:5, 16:9, etc.)
- Posters and product cards requiring quoted in-image text
- Web-grounded imagery referencing current events or real entities
- Reproducible variant testing with seed-locked compositions
- Designers iterating on social media assets quickly
- Marketers producing thumbnail batches for A/B testing
- Developers integrating image generation into CI pipelines
- Content creators needing platform-native vertical or wide-format images
- Anyone explicitly requesting Nano Banana 2 or Gemini image generation
nano-banana-2 FAQ
Use Nano Banana 2 for rapid drafts, batch thumbnails, and typography-heavy assets. Default to Nano Banana Pro for hyperrealistic portraits or when maximum detail matters more than speed.
Quote the exact characters in your prompt (e.g., the label reads 'AURA') and specify placement and font style. Vague references like 'with the brand name on it' produce unpredictable results.
Yes. `enable_web_search` adds both latency and cost. Only enable it when the prompt explicitly references current events or real-world entities that require fresh context.
Supported tiers are 0.5K (drafts), 1K (default), 2K (final), and 4K (max). Default to 1K unless the user explicitly requests higher; 2K and 4K cost more.
No. This endpoint generates images from text only. For subject-preserving edits (swap background, apply changes), use the sibling `nano-banana-edit` skill instead.
Full instructions (SKILL.md)
Source of truth, from agentspace-so/runcomfy-agent-skills.
name: nano-banana-2
displayName: "Nano Banana 2 — Pro Pack on RunComfy"
description: >
Generate images with Google Nano Banana 2 (Gemini-family flash-tier
text-to-image) on RunComfy — bundled with the model's documented
prompting patterns so the skill gets sharper output than naive
prompting against the same model. Documents Nano Banana 2's strengths
(rapid iteration, in-image typography rendering, predictable framing,
optional web-grounded context), the resolution-tier pricing, the
safety-tolerance dial, and when to route to Nano Banana Pro / GPT
Image 2 / Flux 2 / Seedream instead. Calls
runcomfy run google/nano-banana-2/text-to-image through the local
RunComfy CLI. Triggers on "nano banana", "nano-banana-2", "nano banana 2",
"google image gen", "gemini image", or any explicit ask to generate
with this model.
homepage: https://www.runcomfy.com
license: MIT
Nano Banana 2 — Pro Pack on RunComfy
runcomfy.com · Model page · GitHub
Google Nano Banana 2 — the flash-tier text-to-image model in the Gemini family — hosted on the RunComfy Model API. Optimized for ideation, social-thumbnail batches, and rapid drafts with strong in-image typography.
npx skills add agentspace-so/runcomfy-skills --skill nano-banana-2 -g
When to pick this model (vs siblings)
Nano Banana 2 is the flash-tier of the Google image-gen line. Pick it when iteration speed and predictable framing matter more than maximum detail.
| You want | Use |
|---|---|
| Rapid drafts, social thumbnails, batch variants | Nano Banana 2 |
| In-image typography with predictable rendering | Nano Banana 2 |
| Web-grounded image (current events / real entities) | Nano Banana 2 + enable_web_search |
| Image edit (preserve subject, swap background) | Nano Banana Edit (sibling skill) |
| Heavy stylization, painterly look | Flux 2 |
| Maximum prompt adherence + multilingual text | GPT Image 2 |
| 2K–4K hero shots, max realism | Seedream 5 |
| Hyperrealistic portrait | Nano Banana Pro |
If the user said "Nano Banana" / "nano-banana-2" / "Gemini image" explicitly, route here regardless. If they said "Nano Banana" without specifying 2 vs Pro, default to Pro for portraits and 2 for everything else.
Prerequisites
- RunComfy CLI —
npm i -g @runcomfy/cli - RunComfy account —
runcomfy loginopens a browser device-code flow. - CI / containers — set
RUNCOMFY_TOKEN=<token>instead ofruncomfy login.
Endpoints + input schema
google/nano-banana-2/text-to-image
| Field | Type | Required | Default | Notes |
|---|---|---|---|---|
prompt | string | yes | — | Subject-first description. |
num_images | int | no | 1 | 1–4. Use 4 for ideation rounds. |
seed | int | no | 0 | Reuse for reproducibility. |
aspect_ratio | enum | no | auto | auto, 21:9, 16:9, 3:2, 4:3, 5:4, 1:1, 4:5, 3:4, 2:3, 9:16. |
resolution | enum | no | 1K | 0.5K (drafts), 1K (default), 2K (final), 4K (max). |
output_format | enum | no | png | png, jpeg, webp. |
safety_tolerance | int | no | 4 | 1 (strict) – 6 (permissive). |
limit_generations | bool | no | true | Limit each prompt round to one generation. |
enable_web_search | bool | no | false | Adds web grounding (extra cost + latency). |
For image edit (preserve subject + apply changes), see the sibling nano-banana-edit skill.
How to invoke
Default draft (1K, square, png):
runcomfy run google/nano-banana-2/text-to-image \
--input '{"prompt": "<user prompt>"}' \
--output-dir <absolute/path>
Vertical 4-up batch for ideation:
runcomfy run google/nano-banana-2/text-to-image \
--input '{
"prompt": "<user prompt>",
"num_images": 4,
"aspect_ratio": "9:16",
"resolution": "0.5K"
}' \
--output-dir <absolute/path>
Final at 2K with seed lock:
runcomfy run google/nano-banana-2/text-to-image \
--input '{
"prompt": "<user prompt>",
"resolution": "2K",
"aspect_ratio": "16:9",
"seed": 42
}' \
--output-dir <absolute/path>
Web-grounded (current event / real entity):
runcomfy run google/nano-banana-2/text-to-image \
--input '{
"prompt": "<prompt referencing a real-world event from this week>",
"enable_web_search": true
}' \
--output-dir <absolute/path>
Prompting — what actually works
Subject-first declarative grammar. "A cinematic close-up portrait of an American woman standing under neon lights in rainy Tokyo, shallow depth of field, reflective wet streets, ultra-detailed, realistic skin texture" — primary subject, then action, environment, style, camera. Front-load subject; trail with directives.
Exact text quoting for in-image typography. "The label reads 'AURA' in clean bold sans-serif, centered, white on black" — quote the literal characters. Specify placement and font style. Don't say "with the brand name on it" and hope.
Consistent seeds for refinement. Lock seed when iterating a single prompt across small variants — keeps composition stable.
Web-grounding, sparingly. Turn on enable_web_search only when the prompt names current events / real entities. Adds latency + cost; off by default.
Don't conflict styles. "minimalist + ornate + retro + cyberpunk" cancels. Pick 1–2 anchors.
Anti-patterns:
- Trying to verbally describe a stable subject identity — use the edit endpoint with image refs instead.
- Asking for resolutions outside the 4 tiers → 422.
- Aspect ratios outside the 11 supported values → 422.
- Non-quoted in-image text → unpredictable rendering.
Where it shines
| Use case | Why Nano Banana 2 |
|---|---|
| Marketing draft thumbnails (batch of 4) | Fast iteration at 0.5K, then promote winner to 2K |
| Social-platform-native | Wide aspect ratio support including 9:16, 4:5, 21:9 |
| In-image typography for posters / cards | Predictable text rendering when characters are quoted |
| Web-grounded current-event imagery | enable_web_search integrates fresh info |
| Reproducible variant testing | Strong seed + consistent framing |
Sample prompts (verified to produce strong results)
Cinematic portrait (page example):
A cinematic close-up portrait of an American woman standing under neon
lights in rainy Tokyo, shallow depth of field, reflective wet streets,
ultra-detailed, realistic skin texture
Brand-asset card with quoted text:
A minimalist 16:9 product card: a matte black ceramic mug centered on a
soft warm-grey paper background, rim highlight from upper-left, the
headline "Brewed Quietly" in clean bold sans-serif top-right, balanced
negative space below, e-commerce ready, clean studio lighting
Vertical platform-native:
A 9:16 vertical hero for a wellness brand: a single ceramic teacup on a
linen runner, soft morning side-light, the words "Slow Down" in
hand-drawn serif large at the top, gentle steam rising, neutral color
palette, uncluttered
Limitations
- Still images only. No video on this endpoint.
- Max 4 outputs per request.
- Web search adds latency + cost — only enable on demand.
- 2K / 4K cost more — default to 1K unless user asked for higher.
- For image edit, use the
/editendpoint — not this one.
Exit codes
| code | meaning |
|---|---|
| 0 | success |
| 64 | bad CLI args |
| 65 | bad input JSON / schema mismatch |
| 69 | upstream 5xx |
| 75 | retryable: timeout / 429 |
| 77 | not signed in or token rejected |
Full reference: docs.runcomfy.com/cli/troubleshooting.
How it works
The skill invokes runcomfy run google/nano-banana-2/text-to-image with a JSON body matching the schema. The CLI POSTs to https://model-api.runcomfy.net/v1/models/google/nano-banana-2/text-to-image, polls the request, fetches the result, and downloads any .runcomfy.net/.runcomfy.com URL into --output-dir. Ctrl-C cancels the remote request before exit.
Security & Privacy
- Token storage:
runcomfy loginwrites the API token to~/.config/runcomfy/token.jsonwith mode 0600 (owner-only read/write). SetRUNCOMFY_TOKENenv var to bypass the file entirely in CI / containers. - Input boundary: the user prompt is passed as a JSON string to the CLI via
--input. The CLI does NOT shell-expand the prompt; it transmits the JSON body directly to the Model API over HTTPS. No shell injection surface from prompt content. - Third-party content: image / mask / video URLs you pass are fetched by the RunComfy model server, not by the CLI on your machine. Treat external URLs as untrusted; image-based prompt injection is a known risk for any image-edit / video-edit model.
- Outbound endpoints: only
model-api.runcomfy.net(request submission) and*.runcomfy.net/*.runcomfy.com(download whitelist for generated outputs). No telemetry, no callbacks. - Generated-file size cap: the CLI aborts any single download > 2 GiB to prevent disk-fill from a malicious or runaway model output.
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