Toss Apps

2. Development Frameworks & SDKs

Implementations

• Web (WebView): Uses @apps-in-toss/web-framework. Mandatory TDS WebView for non-game apps.
• React Native: Uses @apps-in-toss/react-native-framework with file-based routing.
• Game Engine: Unity/Cocos support via plugins.

JavaScript SDK (AppsInToss object)

The AppsInToss SDK (likely available globally or via the framework) provides:

• Routing: Internal navigation and query parameter handling.
• System Control: Controlling the native back button behavior and app lifecycle.
• Standard APIs: Standard Web APIs (window.open, etc.) are generally supported within the WebView context.

Design Tools

• Toss AppBuilder (Deus): Build screens using TDS components. Supports branding and prototyping.
• Figma: Official component library for design consistency.

3. Toss Design System (TDS)

Foundation

• Colors (v5): Perceptually uniform color space. Uses hierarchy tokens for dark/light mode consistency.
• Typography: Dynamic sizing and line height tokens (accessibility-friendly).

Key Components

• Layout: Top, BottomCTA, Bottom Info, ListHeader, ListRow, Board Row.
• Input: TextField, SplitTextField, TextArea, Checkbox, Switch, Keypad (Alphabet, Secure, Number).
• Feedback: Skeleton (patterns: topList, cardOnly), Badge, Bubble, Overlays.
• Media: Asset (Icons, Images, Videos, Lottie).

Utilities & Hooks

• Overlay Extension: useDialog, useToast, useBottomSheet.
• System: useVisualViewport for viewport management.

4. Backend & Security (mTLS)

• Requirement: All S2S communication must use mTLS.
• Certificates: Issued via the Developers Console.
• Network: Allow Toss Inbound/Outbound IP ranges in your firewall.

5. S2S API & Authentication

Toss Login (OAuth2)

• Profile Endpoint: GET /api-partner/v1/apps-in-toss/user/oauth2/login-me
• Authorization: Bearer {AccessToken}
• Note: User profile fields may be null based on consent.

Core Features

• In-App Payment (IAP): Consumable/Non-consumable. Refunds follow OS policies.
• Smart Message: Push (OS) and Notification (Bell). Titles max 13 chars, body max 20 chars.
• Promotion: Toss Points integration via S2S APIs.
• Game Center: Global leaderboards and player profiles.

6. AI & LLM Integration

MCP Server Support

Apps in Toss provides an MCP (Model Context Protocol) server for Cursor and Claude Code.

• Benefits: AI refers to SDK docs directly, detects API errors, and generates accurate code.

Search & Installation

• docs-search: Semantic search based on the comprehensive llms-full.txt index.
• Codex: Install via $skill-installer using repo toss/apps-in-toss-skills.
• Claude Code: Install from marketplace.

7. Testing & Launch Checklist

• Sandbox App: Mandatory for local/TDS testing.
• QR Test: Use intoss-private:// scheme for private bundle testing.
• UX Writing: Review mandatory UX Writing Guide to pass inspection.