The GPT-Image studio that
lives on your Mac.
Generate with gpt-image-2, gpt-image-1.5, gpt-image-1 and gpt-image-1-mini — through your own Azure OpenAI or OpenAI account. Prompts, history, API keys: none of it ever leaves your machine. Pay only what the model provider charges you, no markup.
See it in action
Native SwiftUI throughout. No web views, no loading spinners.
Generate
Full parameter inspector. Size up to 4K, quality, format, transparent background — every documented field in one panel.
Templates
Pick a template, fill in the variables, generate. Covers, parameter presets, and folders — all built in.
Library
Tag, rate, search, batch-export. Every image embeds the full prompt and token cost as metadata.
Image Details
Every generation's recipe at a glance — model, dimensions, token usage, prompt, rating, tags. One-click copy or export.
An open template standard
Most AI image tools have no prompt reuse at all. NyxAstra ships a standardized, shareable template format — so you never write the same prompt twice, and the community can build on each other's work.
Typed variables
Text, multiline, enumeration, number — each variable has a type, default value, and optional allowed-values list. Users fill in blanks instead of editing raw prompts.
Locked presets
Each template can pin size, quality, format, and background. The author decides the optimal settings; the user just fills in the creative parts.
Portable JSON
.nyxtemplate is just JSON — with the cover image embedded as base64. Share via AirDrop, Slack, Git, or email. Double-click to import. No account required.
Template Gallery
A handful of community-curated templates. Browse the full gallery and contribute your own.
Event Poster
Product Hero Shot
Logo Concept
Cinematic Portrait
Recommendation Poster
Linear Character Illustration
Everyone can contribute — export your template from NyxAstra, submit a PR or open an issue.
Why NyxAstra
Most AI image apps lock you into their cloud, charge a subscription on top of model fees, or are an Electron browser in a trench coat. NyxAstra is none of those.
| NyxAstra | Typical cloud SaaS | Web playground | |
|---|---|---|---|
| Where prompts & images live | On your disk | Their servers | Their servers |
| Bring your own API key | ✓ | Sometimes, with markup | ✓ |
| Subscription required | Never | Yes — $10–$30/mo | Pay-as-you-go via account |
| Standardized prompt templates | Open .nyxtemplate format | Proprietary or none | — |
| Template sharing & community | GitHub gallery, open contributions | Locked to platform | — |
| Full parameter access | Every documented field | Curated subset | ✓ |
| Searchable on-disk library | Tags, ratings, batch export | Cloud only | Manual download |
| Native macOS app | Swift 6 + SwiftUI | Electron / web | Browser only |
Core features
Local-first, BYOK
Encrypted credential vault, on-disk library, zero telemetry, no NyxAstra account. Network traffic only goes to the model provider you typed in.
Every parameter, surfaced
Size up to 4K (or auto), quality, n, format (PNG/JPEG/WebP), compression, transparent background, moderation, user tag — all in one inspector panel.
Reference image editing
Drag & drop reference images to guide the AI. Perfect for style transfer, variations, and iterative refinement.
Token-aware library
Every saved image embeds the prompt, parameters, and exact token count. The recipe that made the image is literally inside the file.
Bulk operations
Multi-select in Library and Templates. ⌘A, Delete, Esc shortcuts. Batch-delete with warnings, batch-export to a single bundle.
Native Swift, modular
Swift 6, SwiftUI, SwiftData. Five Swift packages designed for cross-platform reuse. iOS port on the roadmap.
Frequently asked
Do I need to pay for NyxAstra?
The current public preview is available at no cost. You only pay your AI provider (Azure OpenAI or OpenAI) for the actual model usage — at exactly their published price, with no NyxAstra markup. Future paid editions or add-ons may be offered separately.
What does "BYOK" mean? What do I need before installing?
BYOK = Bring Your Own Key. You'll need either an Azure OpenAI deployment with a gpt-image model, or an OpenAI API key with image-generation access. NyxAstra walks you through pasting it on first launch.
Where are my API keys stored?
In an AES-256-GCM encrypted vault inside the app's sandbox container. Never in iCloud, never on a NyxAstra server (there is no NyxAstra server).
When I open the DMG it says "NyxAstra can't be opened".
Currently NyxAstra ships with ad-hoc signing only — Apple Developer ID notarization is on the roadmap. To open: right-click NyxAstra.app in Applications and choose Open the first time, or run xattr -cr /Applications/NyxAstra.app in Terminal once.
Stop renting your AI tools.
NyxAstra is available now. Download the latest DMG (macOS 14+), paste your API key, and start generating.
NyxAstra is an independent project and is not affiliated with, endorsed by, or sponsored by OpenAI, Microsoft, or Azure. “gpt-image” and other model names are referenced solely to describe interoperability with their respective providers.