Quick Start Guide

Welcome to ChapterAI — an AI-powered interactive storytelling app that lets you write rich, branching narratives with the help of artificial intelligence.

Step 1: Create Your First Story

When you first open ChapterAI, a Welcome Story is created automatically. It walks you through the basics. To create your own story:

1. Tap the book Stories button to open the Stories page.
2. Tap add New Story.
3. Give your story a title and start writing!

Step 2: Set Up Your AI Provider

Before the AI can write with you, you need to connect it to an AI service:

1. Open settings Settings from the top-right action buttons.
2. In the Basic tab, choose your AI provider (e.g., OpenAI, Anthropic, Google Gemini, and many more).
3. Enter your API key — you get this from your AI provider's website.
4. Tap the refresh refresh button next to the model picker to load available models.
5. Select the model you want to use.

Step 3: Start Writing

1. Type what happens next in the text box at the bottom.
2. Tap send (or press Shift+Enter) to send your prompt.
3. The AI will continue your story based on what you wrote.
4. Keep going — each message builds on the previous ones!

Step 4: Explore Your Story

As your story grows, you can:

• Undo/Redo — Navigate through your writing history without losing anything.
• Retry — Get a different AI response if you don't like the current one.
• Create branches — Explore "what if" scenarios without affecting your main story.
• Add chapters — Organize your story into chapters for better structure and to manage the AI context window.

License & Premium Features

ChapterAI offers both a free tier and a premium experience unlocked with a license key.

Free Tier

The free version includes all the core writing features:

• Up to 3 stories
• Up to 5 branches per story
• Up to 50 messages per story
• Built-in system prompts (Conservative, Adaptive, Creative)
• All 16 AI providers
• Chapters, glossary, and brainstorm mode
• Variants and retries
• Undo/redo timeline

Premium Features

With a license key, you unlock:

• Unlimited stories
• Unlimited branches
• Unlimited messages
• Custom system prompts — Write your own AI instructions.
• Story-specific prompts — Per-story AI customization.
• Writing style sliders — Fine-tune pacing, verbosity, tone, and dialogue.
• Google Drive Sync — End-to-end encrypted cloud sync.
• Export — Save stories as PDF, EPUB, Markdown, and more.

Entering Your License Key

1. Purchase a license at our website.
2. After purchase, Polar sends your license key to the email address you used at checkout. The key also appears in your Polar customer portal.
3. Open Settings → Basic.
4. Tap the Enter license key.
5. Enter your license key and tap Activate.

Your license is validated online and then stored securely on your device. Premium features activate immediately.

You can activate the same license key up to 10 times across different devices.

Deactivating Your License

If you need to deactivate your license (e.g., to transfer it to another device), go to Settings, tap the verified in the toolbar and press Deactivate. This frees up your license for use on another device. You can reactivate it later on the same or a different device.

The Writing Interface

The main screen is where all the magic happens. Here's what you'll find:

The Message Area

This is the scrollable area showing your entire story conversation. Messages come in two types:

• Your prompts — What you type to guide the story.
• AI responses — The story content the AI writes based on your direction.

The Input Box

At the bottom of the screen, type your next story direction. This can be anything:

• A scene description: "The hero enters the dark cave and finds a glowing crystal."
• An action: "She draws her sword and charges."
• A dialogue prompt: "The king addresses his court about the upcoming war."
• A direction: "Introduce a mysterious stranger at the tavern."

Action Buttons

The action bar (revealed by tapping the arrow at the top right) gives you quick access to:

• undo Undo — Step back in your story timeline.
• redo Redo — Step forward again.
• refresh Retry — Ask the AI for a different response to your last prompt.
• visibility Reading Mode — Hide your prompts so you can read the story cleanly.
• skip_next Next Chapter — Start a new chapter.
• horizontal_rule Chapter Break — Insert a visual break within a chapter.

Long press

Long press any message to edit it and to show more options.

Reading Mode

Toggle Reading Mode to hide all your prompts and see only the AI-written story text. Perfect for reviewing your story or sharing your screen.

Managing Your Stories

ChapterAI lets you work on multiple stories at the same time, each completely independent.

The Stories Page

Tap book Stories to see all your stories. Each story card shows:

• The story title
• When it was last edited

Creating a New Story

Tap add New Story at the top of the Stories page. Give your story a name and maybe add some custom features. Your new story starts with a blank first chapter, ready for you to begin writing.

Story Actions

Tap the more_vert menu on any story card to:

• Rename — Change the story's title.
• Duplicate — Create an exact copy of the entire story.
• Delete — Permanently remove the story and all its content.

Switching Between Stories

Tap any story card to open it. The app remembers which story you were working on and reopens it automatically next time you launch ChapterAI.

Importing Stories

You can import stories from JSON files (ChapterAI format or Kobold format). Tap the Import button on the Stories page and select a file.

Chapters & Organization

Chapters help you organize long stories and keep the AI focused on what's happening right now.

Why Use Chapters?

AI models have a limited memory (called a "context window"). By splitting your story into chapters, ChapterAI can:

• Send summaries of previous chapters instead of the full text.
• Keep the AI focused on the current scene.
• Help you organize your narrative into logical sections.

Creating a New Chapter

Tap skip_next Next Chapter in the action bar. ChapterAI will:

1. Ask the AI to summarize the current chapter.
2. Update the glossary with any new characters, places, or items.
3. Create a new chapter and give the previous one a generated title.
4. Carry forward the story context so the AI remembers everything important.

Chapter Breaks

Use horizontal_rule Chapter Break to insert a visual divider within a chapter — useful for time skips or scene changes without starting a full new chapter. They can also be added from edit mode and removed with a long press.

Viewing Chapter Summaries

Open the library_books Glossary page and switch to the Summaries tab to see:

• The overall story summary.
• Individual chapter summaries.
• Chapter titles (which you can edit).

Variants & Retries

Not happy with what the AI wrote? You don't have to settle — use variants to get alternative versions.

How Retries Work

When you tap refresh Retry, the AI generates a completely new response to your last prompt. The original response isn't deleted — it becomes a "variant" you can switch back to.

Browsing Variants

You can browse through variants with undo and redo and choose the one you like best before continuing. You can't switch to variants after sending a new message, unless you undo back to that message.

Variant Management

Over time, variants can accumulate. In Settings → Data, you can choose a Variant Purge strategy:

• Never purge variants — Keeps all variants and never deletes any of them.
• Purge variants on chapter creation — Only keeps the variant of the current chapter and when you create an new chapter it deletes variants of the previous chapter.
• Purge variants on send — Only keeps the variants of the user message you are currently on and once you send the next message the variants will be purged.

Branching & Alternate Paths

One of ChapterAI's most powerful features is the ability to create branches — alternate versions of your story that diverge from any point.

What Are Branches?

Think of your story as a tree. The main trunk is your primary storyline. At any point, you can create a branch that takes the story in a completely different direction — without changing the original.

Creating a Branch

1. Long press on any message in your story.
2. Tap call_split Create Branch.
3. A new branch is created starting from that message.
4. Everything you write from here goes into the new branch.

Switching Between Branches

Open the Glossary page and go to the Branches tab. You'll see a visual tree showing all your branches. Tap any branch to switch to it.

Why Use Branches?

• Explore "what if" scenarios — What if the hero chose differently?
• Try different writing approaches — Test various story directions risk-free.
• Preserve alternatives — Keep multiple storylines alive simultaneously.

Deleting Branches

You can Delete branches that you don't like. You can even delete parent branches without losing their children. The app automatically reassigns new parents to branches that had their parent deleted.

Editing Messages

You can edit any message in your story — both your own prompts and the AI's responses.

How to Edit

1. Long press on the message you want to change.
2. Make your changes in the editing area that appears.
3. Tap check Save to confirm your edits.

What Happens When You Edit

Editing a message can't be undone, but if you want to preserve the original, you can always create a branch from the message. If you decide you don't want to make the changes, just tap close Cancel

The Glossary System

The Glossary is like your story's encyclopedia — it automatically tracks characters, places, creatures, items, and more.

How It Works

Every time you start a new chapter, ChapterAI asks the AI to analyze your story and update the glossary. This happens automatically — you don't have to do anything.

What Gets Tracked

The glossary organizes entries into categories:

• Characters — People in your story with their traits and roles.
• Places — Locations with atmosphere and key features.
• Creatures — Non-human beings with abilities and behavior.
• Items — Important objects with properties and purpose.
• Events — Significant happenings and their impact.
• World — Setting details, societies, magic systems, and cultural norms.
• Concepts — Abstract ideas, philosophies, or rules of your world.

Manual Editing

You can also add or edit glossary entries manually:

1. Open the library_books Glossary page.
2. In the Glossary tab, tap more_vert on an existing entry and select edit to edit it, or tap add Add to create a new one.
3. Choose a category, enter a name, and write a description.

Why the Glossary Matters

The glossary is sent to the AI along with your messages. This helps the AI:

• Remember character names, traits, and relationships.
• Stay consistent with established world rules.
• Maintain continuity across chapters.

Brainstorm Mode

Brainstorm Mode is a separate AI chat space designed for planning your story without affecting the main narrative.

What Is Brainstorm Mode?

It's like having a writing coach you can chat with. Ask questions, explore ideas, and get suggestions — all without any of it appearing in your actual story.

How to Use It

1. Tap the lightbulb_outline Brainstorm button to open Brainstorm Mode.
2. Chat naturally — tell the AI what you're working on, what you're stuck on, or what you need help with.
3. The AI will ask you questions and offer suggestions.

Suggestions

If you have tips_and_updates Suggestions toggled on, the AI will give you suggestions (for characters, places, items, creatures, events or world info) that you can save directly to your glossary with one tap of save. This bridges brainstorming and writing seamlessly.

Story Context

If you toggle on book Context, the Brainstorm Mode becomes aware of your current story — it can reference your existing characters, plot, and world when making suggestions. This means you get ideas that actually fit your story.

Suggestion Mode

Suggestion Mode can be used to have the AI generate ideas for what to write next. You can also use it to build a story in the style of Choose Your Own Adventure.

How It Works

When enabled, after every AI response, you'll see 3 brief suggestions for how the story could continue. Each suggestion is a short phrase (5-15 words) describing a possible next action or scene.

Enabling Suggestion Mode

1. Go to Settings → Basic.
2. Toggle Suggestion Mode on.

Using Suggestions

Each suggestion appears as a tappable chip below the AI's response. Tap one to use it as your next prompt — or ignore them and write your own direction.

Suggestions always take the plot in three different directions, so you always have variety to choose from.

System Prompts & Writing Style

System prompts control how the AI writes. They set the tone, creativity level, and writing rules the AI follows.

Built-in Prompt Styles

ChapterAI comes with three preset styles:

• Conservative — The AI sticks very close to what you write. Minimal interpretation or added details. Best for when you want precise control.
• Adaptive — The AI enhances your scenes with sensory details, character thoughts, and minor plot developments while staying true to your direction.
• Creative — The AI takes more creative liberties, adding new elements, characters, and plot connections that enrich the story.

Custom System Prompts

For full control, create your own custom system prompt:

1. Go to Settings → Advanced to find the prompt editor.
2. Tap add and give your prompt a name.
3. Select one of the existing prompts as a starting point or start from scratch.
4. Write instructions telling the AI exactly how you want it to behave.

Per-Story Writing Style

Each story can have its own writing style settings. Go to Glossary → Options to adjust:

• Pacing (1-5) — How fast or slow scenes unfold and how long they are.
• Verbosity (1-5) — How detailed and descriptive the writing is.
• Tone (1-5) — From dark/serious to light/humorous.
• Dialogue Density (1-5) — How much conversation vs. narration.

There are five presets for different writing styles (Balanced, Rapid, Atmospheric, Dialogue Heavy and Lyrical), but you can also create your own custom style by adjusting the sliders.

Story-Specific Prompts

Beyond the global system prompt, each story can have its own additional instructions. This is perfect for genre-specific rules or world-building constraints that only apply to one story.

Note: Custom system prompts, story-specific prompts, and custom writing styles are premium features.

Supported AI Providers

ChapterAI supports 16 different AI providers, giving you maximum flexibility in choosing the model that works best for your writing.

Supported Providers

Switching Providers

You can switch between providers at any time in Settings → Basic. Your stories aren't tied to a specific provider — use whichever model you prefer for each writing session.

Using Local Models

Choose "OpenAI Compatible" as your backend and enter the URL of your local AI server (e.g., LM Studio, Ollama, or any server that uses the OpenAI chat format). This lets you write stories completely offline with no API costs.

Automatic Summaries

ChapterAI automatically maintains summaries of your story to keep the AI informed about what happened in previous chapters.

How Summaries Work

When you create a new chapter, the AI:

1. Reads through the current chapter.
2. Writes a concise summary of key events and emotional beats.
3. Updates the overall story summary with the big picture.
4. Generates a chapter title that captures the essence of what happened.
5. Updates the glossary with any new characters, places, or items introduced.

Summary Injection

In Settings → Advanced, you can control how many previous chapter summaries are sent to the AI. More summaries means better continuity but uses more of the AI's memory.

Editing Summaries

Open Glossary → Summaries tab to view and edit any summary or chapter title. If the AI missed something important or got something wrong, just fix it manually.

Export & Import

Share your stories or move them between devices using ChapterAI's export and import features.

Export Formats

• JSON — Full story data including all branches, glossary, and metadata. Use this for backups or transferring between devices.
• Text (.TXT) — Plain text version. Choose between AI narrative only or including your prompts.
• Markdown (.MD) — Formatted text with chapter headers.
• PDF — Ready-to-print document.
• EPUB — E-book format you can read on Kindle, Apple Books, etc.

Importing Stories

On the Stories page, tap Import and select a supported file. ChapterAI supports:

• ChapterAI JSON — Full story restoration with all data.
• Kobold format — Import stories from Kobold AI.
• Text files — Import plain text with # as chapter separators.

Note: Export in formats other than JSON is a premium feature.

Backup & Restore

ChapterAI provides multiple ways to keep your stories safe with automatic and manual backups.

Automatic Backups

The app can automatically create backups at regular intervals. Configure the number of automatic backups to keep in Settings → Data. Choose from:

• Off — No automatic backups.
• 1 backup — Keep only the most recent automatic backup.
• 3 backups (default) — Keep the three most recent automatic backups.
• 5 backups — Keep up to five automatic backups for extra safety.

Manual Backup

Tap "Create Backup" in Settings → Data to create a snapshot of your entire database right now. One manual backup is saved at a time — creating a new one replaces the old one.

Restoring a Backup

When restoring, you have two options:

• Override — Completely replaces your current data with the backup. Use this if something went wrong and you want to go back in time.
• Merge — Combines the backup data with your current data. Stories that exist in both are kept as the newer version. Stories only in the backup are added. Nothing is deleted. This works the same way as cloud sync merging.

Export & Import Database

You can also export your entire database as a file and import it on another device or as a complete backup:

• Export Database — Saves the complete database to a file you can store anywhere.
• Import Database — Loads a previously exported database file. Supports merge and override modes.

Database exports include a version number, so you can restore from backups made with older versions of ChapterAI.

Google Drive Sync

Sync your stories across multiple devices using Google Drive with end-to-end encryption.

How Sync Works

1. Sign in with your Google account in Settings → Data.
2. Your stories are encrypted on your device before being uploaded.
3. Only your devices can read the data — Google and ChapterAI never see your stories.
4. When you open ChapterAI on another device, it downloads and decrypts your stories.

End-to-End Encryption

All synced data is encrypted using industry-standard AES-256 encryption. A master key is generated on your first device and securely shared with your other devices using public-key cryptography. This means:

• Your stories are unreadable to anyone but you.
• Even if someone accesses your Google Drive, they can't read your data.
• ChapterAI never sees or stores your stories on any server.

Multi-Device Setup

When you sign in on a new device:

1. The new device generates a secure key pair.
2. Your existing device receives an approval request.
3. Once approved, the encryption key is securely transferred.
4. Both devices can now sync freely.

Device Management

Tap "Manage" in the sync section to see all connected devices, approve new ones, or remove old ones.

Note: Google Drive Sync is a premium feature.

Checking for Updates

ChapterAI checks for updates automatically when you start the app, so you always have the latest features and fixes.

Automatic Update Check

Every time you launch ChapterAI, it quickly checks if a new version is available. If one is found, you'll see a notification with the option to download and install it.

Manual Update Check

You can also check anytime by going to Settings → Data and tapping "Check for Updates".

What's New

After updating, ChapterAI shows you a "What's New" popup on first launch, highlighting the new features and improvements in the update.

Advanced Settings

For users who want more control, the Advanced tab in Settings offers additional options.

Summary Injection

Controls how many previous chapter summaries are included when the AI generates a response. Higher numbers mean better continuity but use more of the AI's context window.

Previous Chapter Tail

Helps maintain continuity by including the last part of the previous chapter's text. This is useful for keeping the AI's writing consistent across chapters. Default is one message from the previous chapter, but you can adjust this in the settings.

Generation Settings

You can adjust the AI's response behavior using the following parameters:

• Temperature — Controls creativity. Higher values (e.g., 1.0) produce more creative and varied responses, while lower values (e.g., 0.2) make the AI more focused and deterministic.
• Max Context Tokens — Limits the number of tokens the AI can use from the context. If the context exceeds this limit, older messages are truncated to make room for new ones, while keeping the system prompt intact.
• Max Output Tokens — Sets the maximum length of the AI's response. Higher values allow for longer, more detailed responses, while lower values keep responses concise.

Prefix

Add text that appears before every AI response. Some users use this for formatting instructions or continuation cues.

Hide Thinking

Toggle visibility of AI reasoning/thinking content for models that support extended thinking.

Appearance & Accessibility

Theme

The app has five built-in themes that you can choose from in Settings → Basic. You can choose:

• Midnight Black — Dark background with purple accent colors.
• Clear White — Light background with blue accent colors.
• Warm Grey — Soft grey background with orange accent colors.
• Steel Blue — Cool blue overall look.
• Relaxing Sepia — Sepia-toned theme for a classic writing vibe.

Font Size

Choose from four font sizes in Settings → Basic:

• Small — Compact text, more content visible.
• Normal — Default comfortable reading size.
• Big — Larger text for easier reading.
• Huge — Extra large text for accessibility.

Desktop Features

ChapterAI on Windows, macOS, and Linux includes extra features designed for larger screens.

Side Panels

On wide screens, the Glossary, Settings, and other pages can open as side panels alongside your main writing view. This lets you reference your glossary or adjust settings without leaving your story.

Window Management

ChapterAI remembers your window size, position, and whether it was maximized or fullscreen. Everything is restored exactly as you left it.

Keyboard Shortcuts

Use Shift+Enter to send messages, keeping the standard Enter key free for line breaks in your prompts.

Troubleshooting

"No response from AI"

• Check that you've selected a backend and entered an API key in Settings.
• Make sure you've loaded models (tap the refresh button next to the model picker).
• Check your internet connection.
• Verify your API key is valid and has credits/quota remaining.

"Sync isn't working"

• Make sure you're signed in to Google on both devices.
• Approve the new device from your existing device when prompted.
• If the master encryption key is missing, use the "Regenerate Key" button.
• Check that you have internet access on both devices.

"The AI seems to have forgotten earlier events"

• This usually happens in long chapters. Create a new chapter to let the AI summarize and carry forward the important details.
• Check the glossary to make sure key story elements are recorded there.
• Increase the Summary Injection count in Advanced Settings.

"My story data seems corrupted"

• Try restoring from an automatic backup in Settings → Data.
• If you have Google Drive Sync, you can force-download the cloud version.

Privacy & Your Data

Where Is My Data Stored?

All your stories, settings, and data are stored locally on your device. ChapterAI does not have any servers that store your content.

What About AI Providers?

When you send a prompt, it goes directly from your device to your chosen AI provider (e.g., OpenAI, Anthropic). ChapterAI never acts as a middleman. Review your AI provider's privacy policy to understand how they handle your data.

Google Drive Sync

If you use sync, your data is encrypted on your device before being uploaded to your own Google Drive. The encryption key never leaves your devices, so the data is unreadable to anyone else — including Google.

No Tracking or Analytics

ChapterAI does not collect any usage data, analytics, or telemetry. The app does not phone home. Your writing is completely private.