Under the hood
OMG! How does Sundrip do it?
For the curious, the technical, and anyone who's ever wondered what's actually happening between "generate" and "once upon a time."
The unfiltered version — how Sundrip actually works.
Story Generation
Every story is assembled from your preferences, your family's data, and intelligent systems specifically engineered to encourage diversity and prevent repetition. We analyze previous stories to ensure each new narrative feels fresh and distinct.
Advanced AI
We use leading AI models, tuned dynamically at generation time rather than left static. Story elements are weighted and adjusted on the fly — so every story feels crafted for the child reading it, not generated for anyone.
Premium members get priority access to the latest models. On the image side, we're standing up our own fine-tuned Flux model with a custom LoRA, purpose-built to keep a child's likeness richer and more consistent from page to page. We're also developing our own proprietary text model for personalized children's storytelling, currently in pre-training development.
Story Uniqueness
Every story is shaped by our diversity engine — a system that balances narrative elements, literary techniques, and storytelling patterns at inference time. Even identical preferences produce distinct stories because each generation draws from a dynamic pool of creative approaches.
We continuously learn from user engagement signals. Over time, this feedback becomes invaluable training data that informs our proprietary model, creating a flywheel where every story makes future stories better.
Story Elements — What You Can Control
Your story preferences give you direct control over the creative DNA of every story generated for you. These selections are tracked individually, rotated based on recency and usage, and combined with the personalization engine below.
Story Insights
Every generation run is logged — the model invoked, the candidates scored from the element pool, and the weight each one carried in the final selection. That log is stored with the story, so the reasoning behind a choice can be reconstructed after the fact. Premium members can see the entire process of how their story was created, down to the individual element and model api requests.
The Personalization Engine
This is where your family's data gets translated into story ingredients — and where we decide how much of it to use in any given story.
How personalization works
When a story is generated, your personalization level acts as a guide for how much of your family's data and preferences gets woven in. Everything you've added — your children's details, interests, relationships, favorite places, and more — is treated as a pool of ingredients, each weighted by how impactful it tends to be when it appears in a story. The engine selects from that pool thoughtfully, making sure no single element shows up so often it loses its magic.
Recency plays a big role. Elements that haven't featured in your recent stories are more likely to be chosen, which keeps things feeling fresh week over week. Your story preferences — tone, genre, format, narrative structure, and more — are handled the same way, rotating naturally rather than defaulting to the same combination every time.
Location gets special treatment — it appears occasionally as a pleasant coincidence rather than a predictable pattern.
Audience Elements
Setting Elements
Story Levers
Image Generation
Illustrations aren't just decorations — they're generated with the same diversity-first approach as the stories themselves.
Cover Image
Each story receives a unique cover illustration generated from the story's content. The cover establishes the visual identity for the story and informs the look and feel of any subsequent page illustrations.
Page Images
A subset of story pages receive illustrations, generated to reflect what's happening in that moment. Character and visual consistency is maintained across pages within the same story. Premium members receive a higher ratio of illustrated pages.
Bringing Your Child Into the Story
If you've uploaded a photo for your child and they're a character in the story, there's a real chance they'll appear as themselves — their actual likeness, illustrated right into the scene. The higher your personalization level, the more likely this is to happen, since it's treated as one of the richer, more literal forms of personalization the engine can reach for.
Visual Diversity Parameters
To prevent illustrations from feeling samey across stories, we inject a set of randomized visual parameters at generation time. Premium members get access to higher-quality image models, and a higher percentage of pages receive illustrations.
Media Style
Watercolor · Comic · Ink wash · Painterly · etc.
Color Theme
Warm muted · High contrast · Pastel · Monochrome · etc.
Composition
Character position · Camera angle · Foreground depth · etc.
And many more parameters varied per story
Story Series
For Premium members — the ability to turn any story into an ongoing narrative (Coming Soon)
How Series Work
Premium members can designate any story — their own, or a public story another user has made series-eligible — as the seed for a series. The next generated story then continues that narrative in one of three formats:
Serialized
A direct continuation — same characters, same world, picking up where the last story ended.
Episodic
The same characters return in a new self-contained adventure, like a TV series with recurring leads.
Anthology
A thematically linked story set in the same world, with new characters and a fresh plot.
Note: when a story is made series-eligible by its author, it can no longer be set to private or deleted. Public availability is required for others to build on it.
System Infrastructure
The systems that keep stories generating reliably, quickly, and at scale.
Frontend
Next.js
Server-rendered React with edge delivery
Backend
Django
Python API handling story logic, user data, and scheduling
Cloud Infrastructure
AWS
Managed, scalable infrastructure across compute, scheduling, and queuing — ECS, EventBridge, SQS, Cloudfront, and more
Real-time Updates
SSE
Server-Sent Events stream live story generation progress directly to your profile — no refresh needed
SES
Transactional email for passcodes, support, and notifications
Authentication
Passwordless
Secure one-time passcodes via email — no passwords to forget or compromise
Data & Privacy
What we collect, what we don't, and how your family's information is used.
What we use your data for
- Personalizing story generation
- Scheduling daily story delivery
- Tracking element usage and recency for diversity
- Improving your preferences over time
- A proprietary model is in the works — purpose-built for Sundrip storytelling, trained on our own story data, ratings, and engagement signals. Not yet in use, but actively in development.
What we never do
- Sell your data to third parties
- Share your children's information externally
- Use your data to train external AI models
- Store payment details on our own servers
Your Child's Photo, Locked Down
If you upload a photo of your child, the original file sits behind a private, authenticated CDN — never a public URL. It's only ever read server-side, to generate that child's likeness for their own stories. No one outside our backend can access it directly, and it's never used for anything beyond your own family's stories.
Common Questions
Things people actually want to know.