# Architecture

**PowerPoint MCP Server uses Windows COM automation to control the actual
PowerPoint application — not just `.pptx` files.** Because it drives
PowerPoint's official COM API (`PowerPoint.Application`), every edit is
rendered and saved by PowerPoint itself, so there's zero risk of producing a
file PowerPoint can't open — and any visual change can be exported to an
image and verified by a vision-capable AI assistant.

## Two equal entry points

The project ships **both** an MCP Server and a CLI. They are first-class,
interchangeable entry points that share the same core, so every operation
behaves identically no matter which you use:

- **MCP Server** hosts the service **in-process** — direct method calls, no
  pipe — which suits conversational, interactive AI clients.
- **CLI** (`pptcli`) talks to a **background daemon** over a named pipe, so
  sessions persist across invocations — ideal for scripted, high-throughput
  automation by coding agents.

The CLI stores an atomic, pipe-scoped ownership record for the daemon and each
PowerPoint process. Every identity includes both its PID and process start time,
so forced cleanup cannot mistake a reused PID for a process owned by PowerPointMcp.
If ownership cannot be proven, cleanup fails without terminating the process.

```mermaid
flowchart TD
    A["AI assistants<br/>(Claude, Copilot, ChatGPT)"] -->|MCP protocol| B["MCP Server<br/>in-process service"]
    C["Coding agents<br/>(Copilot, Cursor, Windsurf)"] -->|pptcli| D["CLI<br/>named pipe → background daemon"]
    B --> E["Core Commands<br/>(shared codebase)"]
    D --> E
    E --> F["PowerPoint COM API<br/>(PowerPoint.Application)"]
```

## Shared core, separate processes

Both entry points build on the same **Core Commands** codebase, so a feature
added to one is automatically available to the other with the same
parameters, defaults and validation. They run as **separate processes**, each
managing its own PowerPoint instance, and do **not** share live sessions with
each other.

## Sessions

Every open presentation is a session identified by a `presentation_session_id`, obtained
from `presentation(action="open", filePath=...)` /
`presentation(action="create", filePath=...)` (MCP Server) or
`pptcli session open <path>` / `pptcli session create <path>` (CLI). Tools and
commands operate on a session until it is explicitly closed, and nothing is
written to disk until `presentation(action="close", presentation_session_id=..., save=true)` /
`pptcli session close <id> --save` is called.

Ready to install? See the [installation guide](installation.md), or dive into
the [MCP Server](mcp-server.md) and [CLI](cli.md) references.