Architecture

OpenPollen uses a layered architecture that decouples message ingestion, routing, Agent execution, and storage.

Architecture Diagram

┌─────────────┐  ┌─────────────┐  ┌─────────────┐
│   WebChat   │  │   DingTalk  │  │    WeCom    │
│  (built-in) │  │  (plugin)   │  │  (plugin)   │
└──────┬──────┘  └──────┬──────┘  └──────┬──────┘
       │                │                │
       └────────────────┼────────────────┘
                        │
                ┌───────▼───────┐
                │    Gateway    │
                │  HTTP Server  │
                │  /health      │
                │  /api/status  │
                │  /api/chat    │
                └───────┬───────┘
                        │
                ┌───────▼───────┐
                │ MessageRouter │
                │  Session mgmt │
                │  Concurrency  │
                │  Commands     │
                └───────┬───────┘
                        │
              ┌─────────▼─────────┐
              │   SessionManager  │
              │  Lifecycle mgmt   │
              │  Timeout GC       │
              └─────────┬─────────┘
                        │
                ┌───────▼───────┐
                │  AgentRunner  │
                │  Claude SDK   │
                │  Skill inject │
                │  Tool assign  │
                └───────┬───────┘
                        │
          ┌─────────────┼─────────────┐
          │             │             │
   ┌──────▼──────┐ ┌───▼────┐ ┌─────▼─────┐
   │ SkillManager│ │ Memory │ │  Plugins  │
   │ Discovery   │ │ SQLite │ │ Registry  │
   └─────────────┘ │  File  │ │ Lifecycle │
                   └────────┘ └───────────┘

Message Flow

1. Ingestion: User messages arrive from channels (WebChat / DingTalk / HTTP API)
2. Routing: MessageRouter finds or creates a Session by channel type and user ID
3. Concurrency: Only one message per session is processed at a time
4. Execution: AgentRunner invokes Claude Agent SDK with injected skills and tools
5. Streaming: Agent replies are streamed as chunks in real-time (WebChat)
6. Memory: Conversation summaries are stored per user namespace for cross-session context

Core Modules

Gateway Server

HTTP server providing REST API endpoints:

• GET /health — Health check
• GET /api/status — Runtime status (active sessions, processing count, uptime)
• POST /api/chat — Send message (supports API Key / JWT auth)

MessageRouter

Core message routing, responsible for:

• Session lookup and creation
• Request deduplication and concurrency control
• Built-in command parsing (/new, /resume, /market)
• Conversation summary storage

SessionManager

Manages all active session lifecycles:

• Sessions identified by channelType + userId + conversationType
• Automatic timeout GC (default 30 minutes)
• Maximum concurrent session limit (default 50)

AgentRunner

Agent execution engine:

• Integrates Claude Agent SDK
• Injects installed skill SKILL.md content into system prompts
• Assigns available tools per configuration
• Supports multi-model switching and budget control

PluginRegistry

Plugin registration center:

• Auto-scans plugins/ directory for plugins
• Manages plugin initialize, start, stop lifecycle
• Supports 4 slots: channel / skill / provider / memory