Jack RuntimeIT and security
Information for administrators reviewing the standalone Jack Runtime 0.9.0.
Installation and binaries
The install.sh and install.ps1 scripts read the release pointer at dl.getjack.dev/runtime/latest.json and download binaries and SHA256SUMS from dl.getjack.dev/runtime/v<version>/. The scripts verify the binary’s SHA-256 before installation. Save and review a script before running it.
Release binaries are jack-linux-x64, jack-darwin-arm64 and jack-windows-x64.exe. The scripts install jack (jack.exe on Windows) into ~/.jack/bin, or %USERPROFILE%\.jack\bin on Windows. They do not add it to PATH automatically.
To check the available version before installing or updating, read dl.getjack.dev/runtime/latest.json. The scripts fall back to getjack.dev/version.json only if the release pointer returns HTTP 404.
Install scripts: install.sh · install.ps1
Release binaries and checksums
Local files
The default Runtime directory is ~/.jack on every OS (%USERPROFILE%\.jack on Windows). It contains runtime.toml (configuration), runtime.db (SQLite), run/ (daemon discovery and locks), sessions/ (session files), tmp/ (temporary files) and runtime.log when logging is enabled. An explicitly configured Runtime directory can replace this default.
telemetry.json holds a random install ID and the notice record; telemetry-usage.json holds daily usage rollups. install.json records a script installation. Secrets use the OS credential store where available, with secrets.env as the file fallback. Session workspaces can also be created in a project’s .jack directory.
What runs on the machine
A jack command that needs the daemon starts it on demand. One daemon per Runtime directory owns the SQLite database and serves MCP over HTTP. The jack mcp process provides the stdio MCP connection for a harness and forwards it to the daemon.
By default the daemon listens on 127.0.0.1 on an OS-assigned port and authenticates local clients with a token. runtime.toml can explicitly change the listen setting and port. The default loopback listener requires no inbound firewall rule. jack daemon stop stops the daemon and its adapter sessions.
The Runtime starts the selected harness CLI to run sessions. Those harnesses and the integrations you enable have their own network destinations and data policies.
Network allow-list
These service destinations use outbound TCP 443. The relay connection opens only after the user logs in with jack relay login; local MCP use needs no relay login. Authentication and relay account requests accompany that login. The list covers Jack services, not harness providers or enabled integrations.
| Host | Purpose | Protocol / port | Direction | Process |
|---|---|---|---|---|
| dl.getjack.dev | Release pointer, binaries and SHA256SUMS for installation | HTTPS / 443 | Outbound | Install script |
| getjack.dev | Version metadata and telemetry settings (/version.json); install scripts | HTTPS / 443 | Outbound | Runtime CLI / daemon, Install script |
| auth.jackforwork.com | Device sign-in, token refresh and revocation for relay login | HTTPS / 443 | Outbound | Runtime CLI / daemon |
| relay.jackforwork.com | Account and registration API; remote MCP over HTTPS / WSS, after login only | HTTPS / WSS / 443 | Outbound | Runtime CLI / daemon |
| n.jackforwork.com | PostHog usage telemetry proxy | HTTPS / 443 | Outbound | Runtime CLI / daemon |
| s.jackforwork.com | Sentry crash reports through /tunnel | HTTPS / 443 | Outbound | Runtime CLI / daemon |
Data and telemetry
Usage events and crash reports use legitimate interest and can be sent before relay login. Usage is associated with a random install ID. The published telemetry catalogue describes the allow-listed fields; code, prompts and file contents are not sent in these reports.
Outside Enterprise, object to product telemetry by email to [email protected]. Website cookie choices are separate from Runtime telemetry.
Security reports and support
For a vulnerability or connection problem, email us with the Runtime version, OS, affected hostname and the security product’s message. Remove credentials and confidential content.