Getting Started

LLM Providers

Connect to AI providers using your own API keys. You only need one provider to get started.

Setup

Switching Models

Tap the model name at the top of any chat to open the model picker. Select a different model and continue the conversation—the new model sees the full history.

When to Use Which

Agents

Agents extend your AI with capabilities like code execution, web search, and file analysis. Each serves a different purpose.

Managing Agents

Go to Settings → Agents to enable/disable agents, update API keys, or remove agents. Enabled agents are available in all conversations.

MCP Servers

Model Context Protocol (MCP) servers extend your AI with custom tools—calendar access, database queries, messaging, and more.

Setup

1. Go to Settings → MCP Servers → Add Server
2. Enter the server URL (e.g., https://server.smithery.ai/@yourserver)
3. sine~ connects and discovers available tools
4. If authentication is required, you'll be prompted (see OAuth below)

OAuth Authentication

Many MCP servers require OAuth to access your data (e.g., Google Calendar, Slack, GitHub). sine~ handles this securely:

1. Add the server - sine~ detects if OAuth is required
2. Tap "Authenticate" - Opens the service's login page in a secure browser
3. Log in & authorize - Grant sine~ access to the specific permissions the MCP server needs
4. Automatic redirect - You're returned to sine~ with the connection complete

Using MCP Tools

Just describe what you want. The AI knows which tools are available and uses them automatically:

• "What's on my calendar tomorrow?"
• "Send a Slack message to #general"
• "Query the database for recent orders"
• "Create a new GitHub issue"

Finding Servers

Browse available MCP servers at smithery.ai. Popular servers include integrations for Google Calendar, Slack, GitHub, databases, and more.

Managing Servers

Go to Settings → MCP Servers to view connected servers, re-authenticate, or remove servers.

Skills

Skills are reusable AI configurations that customize behavior for specific tasks. sine~ includes built-in skills and lets you create your own.

Built-in Skills

These skills are ready to use out of the box:

Using a Skill

1. Tap the sparkle icon in the chat input area
2. Choose a skill from the list (built-in or custom)
3. The skill's behavior applies to your conversation
4. A banner shows which skill is active—tap X to deactivate

Creating Custom Skills

1. Go to Settings → Skills → Add Skill
2. Enter a name and description
3. Write a system prompt that defines the AI's behavior
4. Save—your skill appears in the skill picker

Custom Skill Examples

Memory

sine~ learns about you over time. The memory system extracts facts, preferences, and key information from your conversations and uses semantic search to recall them when relevant.

How It Works

After conversations, sine~ automatically extracts important information—your preferences, decisions, facts you've shared, and topics you care about. This knowledge is stored locally and retrieved using semantic search when relevant to future chats.

Using Memory

The AI naturally recalls what it knows about you:

• "What's my preferred coding style?"
• "Remember my project requirements"
• "Use my usual formatting preferences"
• "What do you remember about my preferences?"

Privacy

All memory data is stored locally on your device, encrypted. Semantic search uses on-device embedding—your memories are never sent to external services.

Secure Files

sine~ securely stores files generated by AI agents and files you share with the app. All stored files are encrypted with AES-256-GCM using platform-secure key storage (Keystore on Android, Keychain on iOS).

How It Works

When agents generate files (E2B code execution, OpenAI Assistants), they're automatically saved to encrypted local storage. Files you share to the app are also stored securely. Access your files anytime from the Files screen.

File Sources

• E2B - Charts, data files, and outputs from code execution
• OpenAI Assistants - Files created by custom assistants
• Shared - Files you share to sine~ from other apps
• Uploaded - Files you attach directly in conversations

Using the Secure Files Browser

From the Secure Files screen you can:

• Search files by name
• Filter by type (images, documents, text) or source
• Preview images and file details
• Download files to your device's Downloads folder
• Share files to other apps
• Delete individual files or clear all

Privacy & Security

Files are encrypted at rest using AES-256-GCM with keys stored in your device's secure enclave (Keystore/Keychain). Only sine~ can decrypt them, and they never leave your device unless you explicitly share them. When you delete a file, both the encrypted data and metadata are permanently removed.

Security Model

sine~ uses encryption for your data at rest—but it's important to understand what this protects against and what it doesn't. We believe in transparency about our security model.

What Encryption Protects Against

• Physical device theft — If someone steals your phone while it's locked or off, your conversations, memories, and files remain encrypted and inaccessible
• Other apps — App sandboxing plus encryption prevents other applications from reading your sine~ data
• Backup extraction — Encrypted database backups are useless without the hardware-bound keys
• Filesystem forensics — Raw access to the device storage yields only encrypted blobs

What It Doesn't Protect Against

When sine~ is unlocked and running, the encryption keys are in memory and decrypted data passes through as you use the app. This means:

• The operating system — iOS and Android have full access to all app memory. Apple and Google control the OS and could technically access decrypted data while the app is running
• Government requests — Legal orders directed at Apple/Google could potentially compel OS-level access
• Malicious OS updates — A compromised OS update could access app data
• Kernel-level exploits — Advanced attacks that compromise the OS kernel

The Trust Model

Using any mobile app means trusting the OS vendor. sine~ encrypts your data as defense-in-depth—it protects against many real-world threats like device theft, malicious apps, and casual snooping. But it cannot protect against a determined adversary who controls the operating system itself.

We use hardware-backed key storage (Secure Enclave on iOS, StrongBox on Android) which makes key extraction significantly harder. But once the app decrypts data into memory for you to use, the OS can see it. This is a fundamental limitation of all mobile apps, not specific to sine~.

Tips & Tricks