Installation

Simon is a standalone desktop application: no server to provision, no database to install by hand. You download the package matching your system, you open it, and everything else falls into place on first launch.

Prerequisites

macOS (Apple Silicon or Intel), Windows or Linux.
Nothing else: Simon ships its own PostgreSQL database, there is no dependency to install separately.

Installing Simon

Download the application from the Download button, then install the format suited to your system:

System	Format
macOS	`.dmg` or `.zip`
Windows	`.exe` installer
Linux	`.AppImage`, `.deb` or `.rpm`

On the very first launch, Simon initializes its embedded PostgreSQL database (on port 5433), creates its storage directories, then offers to create your first company. This initialization only happens once.

Where your data is stored

Everything stays on your machine, in a folder specific to the application:

~/Library/Application Support/simon-agent/

%LOCALAPPDATA%\simon-agent\

~/.local/share/simon-agent/

Inside, Simon keeps each company in its own space:

simon-agent/
├── current-session.json    # Active company
├── companies.json          # List of created companies
└── companies/{SIREN}/      # A company's data
    ├── inbox/              # Uploaded documents, awaiting processing
    ├── pieces/             # Processed and archived documents
    └── reports/            # Generated reports

The database

The embedded PostgreSQL database contains your journal entries, your documents, the reference data and the configuration. It is created automatically and stays accessible locally:

Parameter	Value
Host	`127.0.0.1`
Port	`5433`
User	`postgres`
Database	`simon`

Checking that everything works

The installation is successful when three things are true: the application opens on its home screen, the MCP server is started (the indicator appears in the status bar), and the agent answers a first message. If you get a reply, you’re ready — move on to the first financial year.