Architecture
NEXUS is a local-first desktop workspace. It owns the local windows, agents, work-management state, and user approvals visible in the app. Optional Chainabit cloud services remain a separate account-scoped surface.
Public boundaries
| Surface | Responsibility |
|---|---|
| NEXUS desktop app | Local workspace UI, agent sessions, canvases, browser windows, and work management. |
| NEXUS MCP server | Lets an authorized local MCP client use the capabilities of the running workspace. |
| Chainabit cloud API and MCP server | Account- and workspace-scoped cloud capabilities documented in the Chainabit API section. |
These surfaces are related but not interchangeable. A local NEXUS credential does not authorize a Chainabit cloud request, and a cloud access token does not grant control of a local NEXUS workspace.
Shared local state
Agents in one NEXUS workspace act on the same user-visible workspace state. This is why a canvas edit, work item, or browser action can be inspected from the app instead of existing only inside one agent process.
The local MCP server is available only while NEXUS is running. If the app is closed, local calls fail; they are not forwarded to a cloud fallback.
Local and cloud MCP servers
Connect the local NEXUS MCP server when a client needs to operate the desktop workspace. Connect the Chainabit cloud MCP server when it needs cloud account or workspace capabilities.
The two servers keep separate credentials and capability catalogs. Similar tool names can refer to different resources, so clients should preserve the server identity associated with each tool and must not forward credentials between them.
See NEXUS local MCP vs Chainabit cloud MCP for the integration choice and Local-first for persistence and connectivity behavior.
Governance
Every action remains subject to its own capability, scope, and approval rules. Multi-agent composition adds a separate orchestration gate; enabling one agent action does not automatically authorize a chain of actions across agents.
See Orchestration Governance for the user-facing controls.