Release preview. Publisher contact details are being finalised for the public alpha.
What this policy covers
This policy describes the Mars product website and the free, bring-your-own-key Mars desktop application and CLI. It does not cover independently operated model providers, MCP servers, remote servers or other services you connect.
Mars is an independent software project. Publisher and contact details for the public release are pending confirmation.
When you visit the website
The current website does not include analytics, advertising trackers, account registration or contact forms. It does not set application cookies or store your demo selections in browser storage. Fonts, interface previews and scripts are served as site assets. The demo uses sample content; it does not run an AI model or receive your project files.
Like other websites, requests expose technical information such as an IP address, browser information and requested URLs to the server delivering the site. The site is served at marshub.dev and hosted on Railway; the earlier address marsade.up.railway.app serves the same site. Published installer downloads use Railway object storage. Cloudflare provides the domain’s name service: it answers address lookups and does not carry the pages. These services receive the technical information needed to deliver pages and files; their processing is described in Railway’s Privacy Policy and Cloudflare’s Privacy Policy. The publisher’s own log-retention period has not yet been established for this alpha.
What the application stores locally
Mars stores session history, run records, task context, connection settings and other working data on your computer. Tool output and saved artifacts may contain code, file paths and other information used in a task. The desktop and CLI share application data on the same machine. Desktop preferences and composer drafts may also be stored in the local webview.
Project files remain in the workspace where the tools create or edit them. For SSH work, that workspace can be on your remote server. Local storage is not a promise that every record is encrypted; protect your device, operating-system account and backups.
API keys and connections
Provider keys saved through Mars are kept in the operating system’s credential store. Supported environment variables can also supply provider keys and take precedence over saved keys. A key supplied through the environment must be removed from that environment separately.
Keys authenticate requests to the connection you choose. Review custom endpoint addresses before entering credentials. Do not put secrets in prompts or project content that the agent may send to a model or tool.
What leaves your device
When you run a task, Mars sends prompts and relevant task context to your selected model connection. Depending on the task, this can include conversation history, selected files, code, attachments and tool results. A connection may be a remote provider, your own endpoint or a local model service.
The provider or endpoint operator determines its own processing, retention, training practices and processing locations. Review those terms before using it. The current desktop and CLI do not require a Mars-hosted model proxy.
To discover model limits, Mars reads metadata from your configured provider. When a built-in provider omits limits, Mars downloads the public model catalogue from models.dev and caches it locally for offline use. This request contains no API keys, prompts, conversation history or selected model identifiers; the catalogue service receives ordinary connection information, including your IP address. Custom endpoints use their configured limits.
The Windows desktop checks for software updates at startup, periodically while open, and when connectivity returns. It requests release metadata from the Mars website, at marshub.dev and, if that fails, at the earlier Railway address, using the operating system, processor architecture, the installed app version and a short fingerprint of the installed app file, which lets the catalogue offer the right build. The hosting service also receives normal request information such as an IP address. Update checks do not send prompts, project files or API keys. Downloading and installing an update requires your action. The installer stores acceptance of its bundled documents locally.
When it starts, Mars may download signed agent instructions from the Mars website. The request carries no query, prompts, project files or keys, and Mars uses the instructions only if their signature checks out.
The Library searches the public skills.sh index with the words you type; only those words go to skills.sh. Opening or installing a skill reads it from GitHub and pins its commit, and when the index cannot answer, the search words go to GitHub’s repository search instead.
SSH commands and files go to the remote machine you connect. MCP servers, skills and other tools may access external systems or transmit task data according to their implementation and the access you give them. These connections are not covered by a blanket “everything stays local” guarantee.
Your controls and deletion
You can remove saved sessions, disconnect services and remove saved provider keys. In the desktop app, Settings → Data & privacy → Data folder → Open shows the application’s local data location. Resetting interface preferences only resets those preferences; it does not erase session history or provider credentials.
Removing a session does not undo changes to project files, revoke credentials at a provider, delete backups or erase copies already sent to another service. Manage remote files, backups and provider-side records separately. Uninstalling the application should not be treated as a complete data-erasure procedure.
For information held by an external provider or server operator, contact that operator. Requests concerning information held by the Mars publisher will use the public contact address once it is confirmed.
Changes to this policy
The date on this page identifies this version. If hosting, data collection or connected services change, this notice should be updated to describe the new practices. Check the policy associated with the version of Mars you use.