Spike

Merges email and chat messages into a single chronological inbox using a thread-based conversation model that treats both email threads and chat channels as unified message streams. The system maintains separate protocol handlers for IMAP/SMTP (email) and proprietary chat APIs, then normalizes messages into a common data model with unified search, filtering, and notification rules across both communication types.

Provides synchronous text messaging with real-time presence indicators, typing notifications, and message delivery status (sent/delivered/read) using WebSocket-based push architecture. The system maintains active connection pools per user session, broadcasts presence state changes to all participants in a conversation, and implements optimistic UI updates with server-side conflict resolution for concurrent message edits.

Allows users to edit or delete sent messages with server-side tracking of edit history, showing a 'message edited' indicator and allowing users to view previous versions. Deletions are soft-deletes (messages marked as deleted but retained in database) for audit purposes, with admin override to permanently delete messages. The system tracks who edited/deleted a message and when.

Allows users to pin important messages or conversations to the top of a channel or personal sidebar, and star messages for personal bookmarking. Pinned messages are visible to all channel members (with admin controls to manage pins), while starred messages are personal and not visible to others. The system supports pin limits per channel (typically 10-20 pins) and search filters to find pinned/starred messages.

Implements user authentication using email/password or SSO (Single Sign-On) with support for OAuth 2.0 providers (Google, Microsoft, GitHub) and SAML 2.0 for enterprise deployments. The system manages workspace access through invitation links or admin-managed user provisioning, with support for guest accounts with limited permissions and automatic user deprovisioning when accounts are disabled.

Organizes messages into threaded conversations using a hierarchical tree structure where each message can have parent/child relationships, enabling nested replies and topic isolation. The system supports both email-style threading (based on subject/In-Reply-To headers) and chat-style threading (explicit reply-to-message references), with automatic thread collapsing, unread tracking per thread, and thread-level muting/pinning.

Enables sending a single message to multiple recipients, channels, or groups simultaneously using a broadcast queue system that deduplicates recipients and respects per-user notification preferences. The system supports group definitions (teams, departments, custom lists), message scheduling for delayed delivery, and per-recipient message customization (variable substitution for names, roles, etc.).

Supports file uploads and sharing within messages using a cloud storage backend (likely AWS S3 or similar) with client-side file type validation, virus scanning, and access control. Files are stored with metadata (uploader, timestamp, size), and the system generates preview thumbnails for images and documents, with inline rendering for common formats (images, PDFs, videos).

Implements full-text search across both email and chat messages using an inverted index (likely Elasticsearch or similar) with support for boolean operators, date range filtering, sender/recipient filtering, and file content search. The search engine indexes message bodies, subject lines, file names, and metadata, with ranking based on relevance (TF-IDF or similar) and recency.

Provides granular notification controls with per-conversation settings (mute, mention-only, all messages), notification channels (in-app, email, push, SMS), and quiet hours scheduling. The system uses a preference engine that evaluates notification rules in priority order (conversation-level > channel-level > workspace-level), with support for keyword-based alerts and VIP/priority sender lists.

Provides workspace administration tools for creating teams, managing members, setting permissions, and configuring team-level settings. The system uses a role-based access control (RBAC) model with predefined roles (admin, member, guest) and custom role support, with audit logging for all administrative actions (user additions, permission changes, etc.).

Provides native iOS and Android applications with offline message caching, allowing users to read cached messages and compose drafts without internet connectivity. The system syncs cached messages and drafts when connectivity is restored using a delta sync protocol that only transfers changed messages, reducing bandwidth usage on mobile networks.

Provides webhooks and API endpoints for integrating external tools and services, with support for incoming webhooks (to post messages from external systems) and outgoing webhooks (to trigger actions in external systems). The system includes a limited set of native integrations (Zapier, IFTTT, GitHub, Jira) and a REST API for custom integrations, with API key management and rate limiting.