Architecture

Current Downcity is best understood through five layers:

1. console
2. agent
3. execution context
4. session
5. plugin runtime

Layers

console

• global control plane
• process registry
• city-level configuration and inspection

agent

• owns one project runtime
• holds model access, session store, plugin registry, and runtime host state

execution context

• shared capability surface exposed during execution
• the place plugins read stable runtime abilities

session

• owns one execution thread and its prompt/run state
• the unit that actually runs model + tool flow

plugin runtime

• all capability modules are modeled as plugins
• some are local and action-first
• some are managed and lifecycle-owned

Managed vs local plugins

Local plugins

• usually attached directly to one SDK Agent
• examples: skill, web, asr, tts, auth

Managed plugins

• runtime-owned modules that start and stop with one target agent
• examples: chat, task, memory, contact, shell, schedule

Main takeaway

Do not use the old split-layer language for the current system.

The current model is:

• session executes
• plugins expose capability
• managed plugins own long-lived runtime modules