System tags (the `__sys` tree)

Everything about a node — not just your application data — is represented as tags. The system tags live under __sys/ and are organised by who writes them and how they are restored. You can browse the whole tree in the IDE under the Tag Tree (expand __sys).

The map

__sys/
├── host/                         Host machine facts. Engine-managed; regenerated each boot.
│   ├── about/                    hostname, kernel, architecture
│   ├── clock/                    1 Hz tick: second, minute, hour, day, month, year, timestamp
│   ├── network/                  interfaces, default interface
│   └── stats/                    CPU, memory, disk
└── node/                         This JasperNode instance.
    ├── about/                    engine version, uuid, load state
    ├── user/                     ★ THE ONLY USER-EDITABLE SUBTREE ★
    │   ├── config                application-wide configuration
    │   ├── connectors/<type>/<id>/   per-instance: config, enabled
    │   ├── connectors/<type>/         type-wide: config, discovery trigger
    │   ├── flows/                one tag per saved Flow Exploration view
    │   └── tools_params/         tunable parameters for the built-in tools
    ├── service/                  Engine + system-connector writes only (read-only to you).
    │   ├── connectors/<type>/<id>/   stats (is_connected, status, errors), diagnostics
    │   └── connectors/<type>/         manifest, availability, discovered devices
    ├── stats/                    Engine health (sampled): tag counts, cycle timing, liveness
    └── logger/                   Log streams: debug, info, warning, error

What each part is for

Path	Writable	What it holds
__sys/host/	No	Facts about the machine the node runs on, refreshed at boot, plus a live 1 Hz clock.
__sys/node/about/	No	The engine’s identity: version, a stable uuid, and whether it has finished loading.
__sys/node/user/	Yes	Your configuration: app config, every connector’s config and enabled, tool params.
__sys/node/service/	No	Live connector status & diagnostics, and connector manifests.
__sys/node/stats/	No	Engine health: tag counts, Logic Cycle timing, and how late the node’s heartbeat has run.
__sys/node/logger/	No	The node’s log streams, shown in the IDE’s Logger and Diagnostics screens.

Two rules worth remembering

• __sys/node/user/** is the only place writes are accepted through the normal channels (the IDE, the AI agent, scripts). Configuring a connector means writing under here; nothing else under __sys/ is user-writable. (The IDE and AI can override any tag for development and troubleshooting — an explicit, attributed action.)
• Your project is what backup captures. A project backup takes your user tags (with their scripts and descriptions), each connector instance’s config here under __sys/node/user/, and your saved flows/. Everything under host/, about/, service/, stats/ and logger/ — plus the node’s own built-in system connectors — is regenerated by the receiving node, because it describes that machine and that run.

Handy paths to watch

Path	Why it’s useful
__sys/host/clock/second	A ready-made 1 Hz trigger for periodic scripts
__sys/host/stats/…	Live host CPU / memory / disk
__sys/node/service/connectors/<type>/<id>/stats/status	A connector’s live status (connected, error, …)
__sys/node/logger/error	The error log stream

Because these are just tags, you can subscribe to them, trigger scripts from them, or have the AI agent report on them — exactly as you would your own application tags.