# Concepts

Understand the small set of account, source, notification, tag, metadata, action, and push concepts used by the product.

## One notification system for people and agents

FYInbox centralizes project notifications outside Slack, Telegram and email in one system for people and agents. The current account model remains one person per account; teams are not part of this version.

> **Use the documented agent operations.** An agent can send notifications and use documented source-scoped operations. Do not assume a subscription, polling, discovery or action interface beyond the operations in the API reference.

## Sources and API keys

A source groups notifications from one producer or automation. Its bearer API key selects the source and account on the server. The optional source field inside a payload is descriptive data; it cannot change the source selected by the key.

> **Scope is server-derived.** Producer requests do not choose account or project identifiers. A key can only create and update notifications inside its own source scope.

## Structure and delivery

- Tags provide normalized labels for filtering and triage.
- Metadata stores bounded string key/value pairs for exact filters and later context.
- Actions are explicit HTTPS or mailto links shown with a notification.
- Web Push is an optional delivery view of the same inbox item and can be configured per device and source.