Skip to main content

​
Overview

CodeInk uses IndexedDB to store all your documents entirely in your browser. No data is ever transmitted to external servers or stored in the cloud. This architecture ensures complete privacy and data ownership.
All documents remain on your device. CodeInk has zero access to your content.

​
IndexedDB Implementation

CodeInk implements a simple, efficient storage layer using the browser’s native IndexedDB API.

​
Database Structure

The storage system consists of:
  • Database Name: codeink-docs
  • Object Store: documents
  • Key Path: id (unique document identifier)
  • Database Version: 1

​
Document Schema

Each document stored in IndexedDB contains the following fields: 
interface Document {
  id: string           // Unique identifier
  title: string        // Auto-generated from first heading
  customTitle?: string // User-defined title (optional)
  content: string      // Full markdown content
  createdAt: number    // Unix timestamp (ms)
  updatedAt: number    // Unix timestamp (ms)
}
Documents are automatically sorted by updatedAt timestamp in descending order, showing your most recently edited documents first.

​
Storage Operations

CodeInk’s database layer (src/lib/db.ts) provides four core operations:

​
Read Operations

​
Get All Documents

getAllDocs(): Promise<Document[]>
Retrieves all documents from storage, automatically sorted by last update time.

​
Get Single Document

getDoc(id: string): Promise<Document | null>
Fetches a specific document by its ID. Returns null if not found.

​
Write Operations

​
Save Document

saveDoc(doc: Document): Promise<void>
Creates a new document or updates an existing one. Uses the document’s id field to determine whether to insert or update.

​
Delete Document

deleteDoc(id: string): Promise<void>
Permanently removes a document from storage.
Deleting a document is permanent. There is no server-side backup or recovery mechanism.

​
What Data is Stored

​
Stored Locally in IndexedDB

  • Document content (markdown text)
  • Document titles (auto-generated and custom)
  • Creation and modification timestamps
  • Unique document identifiers

​
NOT Stored Anywhere

  • User accounts or authentication data (CodeInk has no accounts)
  • Analytics or usage tracking
  • IP addresses or device information
  • Cookies for tracking purposes
  • Any data on external servers
CodeInk is 100% client-side. The application code runs entirely in your browser, and your documents never leave your device unless you explicitly export them.

​
Storage Limits

IndexedDB storage limits vary by browser:
BrowserStorage Limit
Chrome/EdgeUp to 80% of total disk space (shared across all origins)
FirefoxUp to 2GB per origin (prompts user if more needed)
SafariUp to 1GB per origin (prompts user after 50MB)
For typical markdown documents, even large codebases with hundreds of documents will use only a few megabytes of storage.

​
Browser Support

IndexedDB is supported by all modern browsers:
  • Chrome 24+
  • Firefox 16+
  • Safari 10+
  • Edge (all versions)
  • Opera 15+

​
Data Persistence

IndexedDB data persists across browser sessions and even system restarts. However, data can be lost in certain scenarios:
Data Loss Scenarios
  • Clearing browser data/cache manually
  • Using incognito/private browsing mode
  • Browser storage eviction (rare, only when disk space is critically low)
  • Uninstalling the browser without data export

​
Backup Recommendations

Since data is stored locally:
  1. Export important documents regularly using the export feature
  2. Use browser profiles to separate work and personal documents
  3. Consider external backups for critical content
  4. Avoid incognito mode for long-term document storage

​
Privacy Guarantees

CodeInk’s architecture provides strong privacy guarantees:

​
What We Can’t See

  • Your document content
  • Document titles or metadata
  • How many documents you create
  • How often you use CodeInk
  • Any information about you or your device

​
Same-Origin Policy

IndexedDB data is isolated by origin (https://codeink.app). This means:
  • Other websites cannot access your CodeInk documents
  • CodeInk cannot access data from other websites
  • Even subdomains cannot access the data without explicit permission
The browser’s same-origin policy ensures that your data remains isolated and secure from other web applications.

​
Open Source Verification

CodeInk is fully open source, allowing you to verify the privacy claims:
  • Source Code: Available on GitHub
  • Database Implementation: src/lib/db.ts contains the complete storage logic (64 lines)
  • No Network Requests: Review the codebase to confirm no data transmission
  • No Tracking Libraries: Check package.json for dependencies

​
Key Dependencies

From package.json, CodeInk uses:
  • @codemirror/* - Editor component (no network activity)
  • marked - Markdown parsing (client-side only)
  • mermaid - Diagram rendering (client-side only)
  • katex - Math rendering (client-side only)
  • shiki - Syntax highlighting (client-side only)
No analytics, tracking, or data collection libraries are included.

​
Technical Architecture

The storage layer uses a promise-based wrapper around IndexedDB: 
// Simplified implementation overview
function openDB(): Promise<IDBDatabase> {
  return new Promise((resolve, reject) => {
    const req = indexedDB.open(DB_NAME, 1)
    req.onupgradeneeded = () => {
      req.result.createObjectStore(STORE_NAME, { keyPath: "id" })
    }
  })
}
Each operation:
  1. Opens the database connection
  2. Creates a transaction (readonly or readwrite)
  3. Performs the operation on the object store
  4. Closes the connection when complete
This design ensures:
  • Atomicity: Operations succeed or fail completely
  • Consistency: Data remains in a valid state
  • Error handling: Failed operations are properly caught and reported

​
Next Steps

Offline Support

Learn how CodeInk works without an internet connection

Export Documents

Back up your documents by exporting to markdown

Build docs developers (and LLMs) love

Get started for freeTalk to us