Nuncio is in active development — building in the open, not shipping vapor.
Master Capability Directory

Full Feature Matrix

Every capability Nuncio is building toward, each tagged with its real status. No invented benchmarks — just what's shipped, what's in progress, and what's planned.

Core Email Engine & Inbox Power Tools

Feature / CapabilityScopeDescriptionStatus
Multi-Account IMAP / SMTP SyncMail EngineUnify multiple IMAP/SMTP accounts into a single local SQLite inbox, tested against mock servers.Available now
JMAP Protocol SupportJMAP DriverA second mail backend alongside IMAP/SMTP, targeting session discovery and JSON-RPC batching per RFC 8620/8621.Planned
SQLite FTS5 Full-Text SearchSearch EngineLocal full-text search over synced mail, backed by SQLite FTS5 — no cloud index required.Available now
Vim-Style Triage MotionsTUI & GUISingle-key triage chords for fast keyboard-driven inbox processing, once the TUI and GUI clients exist.Planned
Rich HTML & Inline Image RenderingReader EngineHTML-to-text formatting for terminal display, with sandboxed HTML rendering as the target for the desktop GUI.Planned
Portable Data Export (MBOX / EML / JSON)Export EngineExport synced mail to standard, portable formats — no lock-in. Real and working today.Available now
Tracking Beacon NeutralizationReader EngineStripping 1x1 tracking pixels and remote CSS triggers before rendering, part of the HTML sanitization milestone.Planned

Calendar & Contacts Management

Feature / CapabilityScopeDescriptionStatus
Natural-Language Event BookingCalendar NLPCreate calendar events from plain text ('coffee with Bob next Tuesday at 2pm'), a target once CalDAV lands.Planned
Local Contacts StoreContacts EngineA dedicated local SQLite contacts database with search and vCard support is under active development.In progress
CardDAV Contacts SyncCardDAV ProtocolSync address books from Google, iCloud, Fastmail, and Nextcloud over CardDAV.Planned
Automated Contact HarvestingMail / ContactsExtract name/email pairs from mail traffic and update interaction metrics automatically.Planned
CalDAV Calendar SyncCalendar EngineCalendar sync exposed end-to-end over the API; the transport exists in the engine but isn't wired up yet.Planned
OAuth 2.0 PKCE for Google Calendar/ContactsAuth EngineLoopback OAuth with refresh tokens stored in the OS keyring, once Calendar/Contacts protocols ship.Planned

NSQL Server-Side Filter Engine

Feature / CapabilityScopeDescriptionStatus
NSQL Parser & CompilerCore EngineCompiles human-readable NSQL text into a typed Rust AST with multi-pass validation. Real and testable today.In progress
ON ACCOUNT & Domain MatchingNSQL / RulesMatch rules against specific accounts, exact addresses, or domain wildcards.In progress
Dry-Run Rule TesterCLI (today)Test a rule against a sample message without touching your database or network state. Works today via the CLI.In progress
Rules Firing on Synced Mailnunciod DaemonRunning validated rules automatically during the live IMAP sync loop — the next milestone on the roadmap.Planned
Signed Outbound WebhooksWebhooksHMAC-SHA256 signed webhook dispatch with redirect blocking and private-IP defenses — implemented in the engine, not yet wired to live sync.In progress
WASM / QuickJS Plugin RuntimePlugin RuntimeSandboxed custom automation scripts with declared capability manifests.Planned

Four Presentation Shells

Feature / CapabilityScopeDescriptionStatus
POSIX Reference CLICLIPipeable JSON output (--json), the E2E driver for the engine, and the only client that exists today.Available now
Native Desktop GUIGUIA visual workspace, split panes, sandboxed HTML viewer, and drag-and-drop rule builder — planned as a separate client repo.Planned
Terminal TUITUIVim motions, single-key triage chords, and a split-view previewer for keyboard-first users.Planned
MCP AI ClientMCPExposes mail, calendar, and rule tools to LLM agents through a governed gateway.Planned

Model Context Protocol (MCP) AI Integration

Feature / CapabilityScopeDescriptionStatus
Local LLM Summarization & TriageLocal AIOffline thread summarization, action-item extraction, and smart replies — a future capability once the MCP client exists.Planned
Claude Desktop & MCP Client IntegrationMCP ProtocolConnect AI agents to local mail and calendar data over stdio through a policy gateway.Planned
RBAC Capability GatewayMCP SecurityFine-grained capability flags, folder whitelists, and audit logging for every agent tool call.Planned
Automatic PII RedactionMCP EnclaveMasking sensitive identifiers before payloads reach an LLM context window.Planned

Privacy, Security & Storage

Feature / CapabilityScopeDescriptionStatus
OS Keyring Credential VaultSecurityPasswords and OAuth tokens stored exclusively in the native OS credential store — real and enforced today.Available now
WORM Audit Hash ChainComplianceImmutable, HMAC-SHA256 hash-chained audit ledger for filter and account mutations — real and verifiable today.Available now
At-Rest Body EncryptionStorageColumn-level encryption for email bodies and subject lines. Not implemented yet — bodies are currently stored unencrypted in the local database.Planned
Attachment Stream EncryptionStorageLarge binary attachments encrypted with a modern stream cipher before being written to disk.Planned
Key & Secret ZeroizationCore VaultExplicit zeroing of secret memory buffers on drop. In progress; not verified complete across the codebase.In progress
Untrusted HTML SanitizationGUI / TUISandboxed rendering with JS execution disabled, for whichever client renders HTML email.Planned
Fail-Closed, Signature-Verified UpdaterDistributionAn updater that refuses to install anything it can't verify — tracked as a hardening milestone before any packaged release.Planned
Self-Healing Storage RecoveryStorage EngineStartup integrity checks and corruption recovery for the local SQLite database.In progress