Master Capability Directory
Full Feature Matrix
A scannable, structured breakdown of every capability built into Nuncio — starting with Core Email and Calendar power tools.
Core Email Engine & Inbox Power Tools
| Feature / Capability | Scope | User Benefit / Specification |
|---|---|---|
| Multi-Account Inbox Aggregation | Mail Engine | Unify unlimited IMAP/SMTP, Google Workspace, and JMAP push accounts into a single local SQLite inbox. |
| Microsecond SQLite FTS5 Search | Search Engine | Trigram full-text index returning instant search results in <10ms across 100,000+ email messages. |
| Vim Triage Motion Velocity | TUI & GUI | Single-key triage chords (j/k/h/l/g i/e/s/d/#) for processing hundreds of emails per minute. |
| Rich HTML & Inline Image Rendering | Reader Engine | HTML-to-ANSI formatting with inline Kitty, iTerm2, and Sixel graphics protocols; press 'o' for browser view. |
| Universal Portable Data Export | Export Engine | Export full accounts, folders, or NSQL query results to standard RFC 4155 MBOX, EML ZIP archives, or JSON/JSONL. |
| Tracking Beacon Neutralization | Reader Engine | Automatic stripping of 1x1 tracking pixels, web bugs, and remote CSS import triggers before rendering. |
Calendar & Contacts Management
| Feature / Capability | Scope | User Benefit / Specification |
|---|---|---|
| Sovereign Contacts Engine (nuncio-contacts) | Contacts Engine | Dedicated local SQLite contacts database with instant trigram FTS5 search index and vCard 4.0 generator. |
| Multi-Provider CardDAV Synchronization | CardDAV Protocol | Sync Google Contacts, Apple iCloud, Fastmail, and Nextcloud address books seamlessly over CardDAV. |
| Automated Email Contact Harvesting | Mail / Contacts | Automatically extracts name/email pairs from incoming and sent messages, updating interaction metrics. |
| Native Event Scheduling & RSVP | Calendar Engine | Accept, decline, or mark tentative on event invitations with automatic ICS payload updates. |
| Google Calendar & Contacts OAuth 2.0 | Auth Engine | OAuth 2.0 PKCE loopback authentication with refresh token storage inside native OS Keyrings. |
Server-Side Email Filter Engine (NSQL)
| Feature / Capability | Scope | User Benefit / Specification |
|---|---|---|
| Nuncio SQL Parser (sqlparser 0.54) | Core Engine | Compiles human-readable NSQL text into typed Rust AST representations with 6-pass validation. |
| ON ACCOUNT & Domain Matching | NSQL / Rules | Match rules against specific accounts, exact emails, or domain wildcards (*, %, %@company.com). |
| Pre-Ingestion Background Execution | nunciod Daemon | Executes priority-ordered rules during background IMAP IDLE / JMAP push loops before database persistence. |
| Dry-Run In-Memory Tester | All 4 Interfaces | Test rules against inbox messages in microsecond time without database or network state mutations. |
| HMAC Webhooks & SSRF Defense | Webhooks | Dispatch signed webhooks with HMAC-SHA256, pre-flight DNS IP blacklisting, and redirect blocking. |
Four Presentation Shells (100% Feature Parity)
| Feature / Capability | Scope | User Benefit / Specification |
|---|---|---|
| Tauri v2 Native Desktop GUI | GUI | Glassmorphic visual workspace, split-pane resizers, sandboxed HTML viewer, and visual drag-and-drop rule builder. |
| Ratatui Terminal TUI | TUI | Vim motions (j/k/h/l/g i/e/s), single-key triage chords, split-view text/HTML previewer, and live log inspector. |
| POSIX Scriptable CLI | CLI | Pipeable JSON output (--json), microsecond search, headless daemon management (nunciod), and shell automation. |
| Native MCP AI Server | MCP AI | Exposes mail, calendar, and rule tools to LLM agents (Claude Desktop, Antigravity, ChatGPT) via Model Context Protocol. |
Native Model Context Protocol (MCP) AI Integration
| Feature / Capability | Scope | User Benefit / Specification |
|---|---|---|
| Claude Desktop & LLM Integration | MCP Protocol | Connect Claude Desktop, Antigravity, and Cursor directly to local mail and calendar databases over stdio. |
| McpAgentPolicy RBAC Gateway | MCP Security | Enforce fine-grained capability flags (read_mail, send_mail, read_calendar), folder whitelists, and PII redaction. |
| Automatic PII Redaction | MCP Enclave | Automatic masking of Social Security Numbers, Credit Cards, and private credentials before payloads touch LLMs. |
Sovereign Privacy, Security & Storage
| Feature / Capability | Scope | User Benefit / Specification |
|---|---|---|
| AES-256-GCM Encryption at Rest | Storage | Column-level encryption for email bodies and subject lines using PayloadCipher. |
| age X25519 Attachment Ciphers | Storage | Large binary attachment streams encrypted with age ciphers and 64KB chunk authentication. |
| Memory Page Zeroing on Drop | Core Vault | Keyring secrets and passphrase buffers locked in memory and zeroed out on drop via ZeroizeOnDrop. |
| Strict HTML Email Sandboxing | GUI / TUI | <iframe sandbox="allow-same-origin"> with CSP default-src 'none' disabling JS execution. |
| WORM Audit Hash Chains | Compliance | Immutable block-linked audit ledger (H_n = HMAC(K, H_n-1 || data)) preventing retroactive tampering. |
| Self-Healing Storage Engine | Recovery | PRAGMA quick_check(10) integrity checks, CorruptedBackupManager isolation, and SqliteRecoveryEngine salvage. |