Overview
Placet consists of three main components:- Web App: the inbox where humans review and respond to messages
- API: the REST endpoint agents and automations use to send messages and receive responses
- Plugin System: extensible message rendering via sandboxed plugins
Agent Communication
Agents interact with Placet through the Agent API (/api/v1/*), authenticated with API keys:
Supported patterns
For a detailed comparison, see Connection Types.
Review System
Agents can request human input by attaching areview to any message. Placet supports 5 built-in review types:
Reviews support expiry (default 24h, max 36h), webhook callbacks, and long-polling. See Agents for payload examples.
File Storage
Agents can upload and attach files to messages via the API. The web app renders inline previews for many formats:
Additional file features:
- Canvas annotations: draw on images with pen, arrow, rectangle, and text tools
- Share links: JWT-based public download links (1h expiry)
- Bulk operations: download as ZIP or delete multiple files
- File browser: searchable gallery with type filters across all channels
Agent Status
Agents report their status via a heartbeat endpoint (POST /api/v1/status/ping). The frontend provides a dedicated Status page showing all agents with:
- Live status indicator (active, busy, error, offline)
- Uptime since last status change
- Message statistics (total, inbound/outbound, success/error)
- Status history timeline