A Windows desktop app for writing text-to-image prompts together with an AI Agent.

Draft on the left, chat on the right. Every change the Agent makes waits for your approval.

Interface: English / 简体中文 / 繁體中文 / 日本語, light and dark mode.

Workspace

- Describe the scene in plain words; the Agent writes the prompt.

- Agent edits show as a red/green diff. Accept or reject each section.

- Prompts are split into sections (Subject, Lighting, Camera…). Each one can be polished, translated, pinned or reordered.

- One-click conversion between natural language, Danbooru tags and JSON.

- Pages and series: up to 10 pages per workspace; one reply can write several pages.

Region Control

- Draw boxes on the canvas and describe each region.

- Layers (foreground / middle ground / background) and 1-, 2- and 3-point perspective guides.

- Exports MOSS-Image layout JSON.

- A dedicated layout Agent builds the layout from your description or a reference image.

Local Interrogate

- Tag Interrogate: 20 ONNX taggers (WD14, PixAI, CL, OppaiOracle).

- NL Interrogate: 15 vision models (Gemma 4, ToriiGate, JoyCaption, Florence-2), runs on your own PC.

- LLM Analysis: compare two API models side by side.

- Reuses models already on disk (BooruDatasetTagManager, NLapt, HuggingFace cache).

- Results go straight to the Agent or into the draft.

Tags & Characters

- 76,000 Danbooru tags built in. The Agent looks tags up before writing and checks them afterwards.

- 74,000 Danbooru characters, with looks and outfit tags listed separately.

- Save your own characters with a name, prompt and picture.

Models

- Works with any OpenAI-compatible API, Google Gemini and Vertex AI.

- Several models in a chain: when one fails, the next one takes over.

- Presets with their own system prompt, temperature and Top P; Skills shape how the Agent writes.

Getting started

0. Visit Penna GitHub repository

1. Download the zip from Releases, unzip, run penna.exe.

2. The app opens in Chinese. Click the gear icon (bottom left) → 软件设置 → 界面语言 → English.

3. Settings → API Management: fill in Base URL and API Key.

API setup guide: https://github.com/storyAura/Penna/blob/main/docs/api-setup.md

All settings and API keys are stored on your PC (keys encrypted with Windows DPAPI).