3. Context and scope
This is the C4 system context: Apollia OS as one box, and everything outside it that it talks to. It sets the boundary before the next pages open the box.
System context
Actors and neighbours
| Neighbour | Relationship | Direction |
|---|---|---|
| Operator / admin | Runs, supervises, and approves. Uses the CLI and the desktop operator app. | Drives Apollia |
| Package author | Declares agents in a manifest and writes typed Python tools and workflows against the SDK contract, then builds the package and installs it. | Builds for Apollia |
| Host product | Embeds and drives the runtime through the stable HTTP API and generated host SDKs. In the federation pattern the host is often Apollia's client and the other way around at once. | Bidirectional |
| External MCP servers | Apollia is an MCP client: it discovers and calls their tools over stdio, streamable HTTP, or SSE. It can also expose a limited inbound MCP server. | Apollia calls out (mostly) |
| Remote model servers | Optional. A remote model is reached through one generic connection to an OpenAI-compatible server at the address the user designates (a self-hosted server or a gateway), or through Ollama. Local stays the default. | Apollia calls out |
| Google / Microsoft | Native connectors act on mail, calendar, and files through OAuth, on scoped permissions. | Apollia calls out |
| Local model and database | The model files, the inference engine the daemon supervises and the SQLite store all live on the same machine. Nothing here is remote. | In-boundary |
What is inside the boundary
Everything that does the agent work: reasoning and planning, the tool calls, memory, governance (permissions, audit, budgets), local inference, and the surfaces (API, CLI, desktop). The next page, Solution strategy, states the structural decisions that shape the inside; Building block view opens it into its parts.
What is deliberately outside
The host's own data store stays on the host side and is read through MCP tools, never copied wholesale into the runtime. Remote inference is opt-in, not a dependency. There is no Apollia-operated cloud service in the loop: the runtime is the product, running on the adopter's machine.