How PromptMason keeps your libraries safe
What PromptMason protects when your libraries sync or back up, and what it doesn't, in plain words.
If you only use PromptMason on one PC, your library stays on that PC. This page is about what changes when a library leaves the PC: when it syncs to your other PCs or your team, or when you turn on backups. For how libraries work day to day, see Personal and team libraries. For everything else that can leave your PC, such as AI features, see Privacy in PromptMason.
How it works
A library that syncs uses a folder in cloud storage you already have, such as OneDrive, Google Drive or Dropbox. No PromptMason server holds your libraries, and there’s no PromptMason account. We never see your libraries.
Every PC keeps its own full copy of the library and works from it, even offline. Changes travel through the folder, locked before they leave the PC.
What PromptMason protects
- Only your library’s members can read it. What’s in the library is locked with a key that only the library’s approved PCs hold. Your cloud storage company, someone the folder was shared with by mistake, or anyone who copies the folder sees files they can’t read.
- Every edit is signed and checked. Each PC signs what it writes, and every other PC checks it before using it. A change that was altered, or that comes from a PC that isn’t in the library, is ignored, and the rest of the library keeps working.
- You approve every PC. Nobody joins a team library, and no PC is added, unless the primary owner approves it. For someone new, the primary owner first compares an approval code with them. See Approve a PC. Nobody can join as an existing member without one of that member’s own PCs, their recovery kit, or the primary owner’s check.
- Removed people are locked out of new work. When someone is removed, the library switches to a new key. People you remove can’t read edits made after every PC has picked up the change. See Remove a person or a PC.
- History shows who made each version. Names come from the library’s own member list, never from the change itself. A ✓ means the edit came from a PC proven to be that person’s; “via AI app” means an AI app made it.
- Backups are locked too. Only you can open them (Backups).
Where your keys are
Your PCs hold your keys, protected by Windows the same way as your other saved sign-ins. Your recovery kit is a spare copy, one file and a code, for when you’ve lost every PC. Your keys are never in the folder in a form anyone else can use. Your settings, your AI assist key and your AI activity log never sync at all.
What it doesn’t protect against
- Someone at your unlocked PC. Whoever is at your unlocked, signed-in PC is you, as with your email. Lock your PC when you step away, and turn on App Lock if others use it (Settings → Privacy & security → Enable App Lock). If a PC is lost or stolen, remove it straight away (Lost or stolen PC or kit).
- Harmful software on an approved PC. It can do anything that PC’s user can do.
- What someone already has. Removing a person stops new changes reaching them; it doesn’t take back what they could already read, copy or export.
- Seeing the shape of the library. Anyone with access to the folder can see that the library exists and how it’s made up: how many files, PCs and members there are, each member’s role, which PCs belong to the same person, when PCs joined or were removed, when each PC is busy, and roughly how big each change is. They can’t see what’s in it, members’ names or its settings. The library’s name is locked inside the files, but the folder PromptMason makes is called “PromptMason - [library name]”, so anyone who can see the folder sees that name.
- Holding files back. Someone who controls the folder can delete files or stop them syncing. PromptMason notices missing changes and puts back what it can, but it can’t force your cloud storage to deliver.
- Checking who a person really is. The approval-code call proves the PC you approve is the one in front of the person you’re talking to. Call them on a number you already know is theirs.
- The primary owner being unexpectedly away. Only the primary owner approves PCs, removes people and changes settings. If they’re away without handing the role over, those things wait until they’re back; editing carries on (The primary owner).
- Losing everything. If you lose every PC and your recovery kit, your personal library can’t be recovered. Nobody else can open it, PromptMason included. In a team library, the primary owner can put you back after a quick call. If you’re the primary owner, nobody can put you back: another owner exports the library and starts a new one (The primary owner).
AI apps and team libraries
An AI app you connect to PromptMason (a connected app) reads and changes your libraries through PromptMason. In a team library, the primary owner decides for everyone what AI apps can do: Read only (recommended), Read and change, or Nothing: AI apps can’t see it, and how many changes an AI app can make per hour. Each person’s own Connected apps setting still applies, and the stricter of the two wins. This setting limits AI agents and Chat. It doesn’t limit a member’s own AI assist or Evaluate. Each member chooses their provider there, so text from the library can still go to the provider a member picks. Changes an AI app makes show “via AI app” in History. See Team libraries and Control what connected apps can do.
Something in the library folder was ignored
You may see this in Notifications. It means PromptMason found a file in the library’s folder that it doesn’t trust, so it ignored it, or put the real one back. The library is fine. See Sync problems for each message. If it keeps happening, check who the folder is shared with in your cloud storage.
Questions
Email support@promptmason.ai.
Want a hand?
Copy this prompt into Claude, ChatGPT or another AI assistant, and it walks you through it step by step.
Explain in plain words how PromptMason protects a team library that syncs through our OneDrive, what it doesn't protect against, and what our team should do to stay safe.
Copy adds a short note about PromptMason and this guide's steps, so the assistant has what it needs.
Explain in plain words how PromptMason protects a team library that syncs through our OneDrive, what it doesn't protect against, and what our team should do to stay safe. About PromptMason: a Windows desktop app for building AI prompts from reusable blocks. A person writes blocks (reusable pieces of prompt text), builds prompts from them on the Build screen (or keeps a Markdown document, such as a Skill), and copies a prompt into an AI tool, runs it in PromptMason’s own Chat, or lets a connected AI agent use it through PromptMason’s built-in MCP server (the Chrome extension copies prompts on any website). AI assist, Evaluate and Chat use a local model that runs on the person’s PC, or their own AI provider. The guides are also on PromptMason’s Help screen, and Chat can answer “how do I” questions from them. Libraries hold the blocks and prompts; a person can sync their personal library to their other PCs and share team libraries, both through a folder in cloud storage they already have (OneDrive, Google Drive or Dropbox). Everything synced is encrypted and every edit is signed and checked. A recovery kit (a file plus a code) is the spare copy of the person’s keys, for when every PC is lost. The official guide for this is "How PromptMason keeps your libraries safe": https://promptmason.ai/docs/security-overview Its full text follows, between the lines. Use it as the source of truth, and if anything I see differs from it, tell me rather than guessing. --- If you only use PromptMason on one PC, your library stays on that PC. This page is about what changes when a library leaves the PC: when it syncs to your other PCs or your team, or when you turn on backups. For how libraries work day to day, see [Personal and team libraries](https://promptmason.ai/docs/libraries). For everything else that can leave your PC, such as AI features, see [Privacy in PromptMason](https://promptmason.ai/docs/privacy-overview). ## How it works A library that syncs uses a folder in cloud storage you already have, such as OneDrive, Google Drive or Dropbox. No PromptMason server holds your libraries, and there's no PromptMason account. We never see your libraries. Every PC keeps its own full copy of the library and works from it, even offline. Changes travel through the folder, locked before they leave the PC. ## What PromptMason protects - **Only your library's members can read it.** What's in the library is locked with a key that only the library's approved PCs hold. Your cloud storage company, someone the folder was shared with by mistake, or anyone who copies the folder sees files they can't read. - **Every edit is signed and checked.** Each PC signs what it writes, and every other PC checks it before using it. A change that was altered, or that comes from a PC that isn't in the library, is ignored, and the rest of the library keeps working. - **You approve every PC.** Nobody joins a team library, and no PC is added, unless the primary owner approves it. For someone new, the primary owner first compares an approval code with them. See [Approve a PC](https://promptmason.ai/docs/approve-device). Nobody can join as an existing member without one of that member's own PCs, their recovery kit, or the primary owner's check. - **Removed people are locked out of new work.** When someone is removed, the library switches to a new key. People you remove can't read edits made after every PC has picked up the change. See [Remove a person or a PC](https://promptmason.ai/docs/remove-someone). - **History shows who made each version.** Names come from the library's own member list, never from the change itself. A ✓ means the edit came from a PC proven to be that person's; "via AI app" means an AI app made it. - **Backups are locked too.** Only you can open them ([Backups](https://promptmason.ai/docs/backups)). ## Where your keys are Your PCs hold your keys, protected by Windows the same way as your other saved sign-ins. Your [recovery kit](https://promptmason.ai/docs/recovery-kit) is a spare copy, one file and a code, for when you've lost every PC. Your keys are never in the folder in a form anyone else can use. Your settings, your AI assist key and your AI activity log never sync at all. ## What it doesn't protect against - **Someone at your unlocked PC.** Whoever is at your unlocked, signed-in PC is you, as with your email. Lock your PC when you step away, and turn on App Lock if others use it (**Settings → Privacy & security → Enable App Lock**). If a PC is lost or stolen, remove it straight away ([Lost or stolen PC or kit](https://promptmason.ai/docs/lost-device)). - **Harmful software on an approved PC.** It can do anything that PC's user can do. - **What someone already has.** Removing a person stops new changes reaching them; it doesn't take back what they could already read, copy or export. - **Seeing the shape of the library.** Anyone with access to the folder can see that the library exists and how it's made up: how many files, PCs and members there are, each member's role, which PCs belong to the same person, when PCs joined or were removed, when each PC is busy, and roughly how big each change is. They can't see what's in it, members' names or its settings. The library's name is locked inside the files, but the folder PromptMason makes is called "PromptMason - [library name]", so anyone who can see the folder sees that name. - **Holding files back.** Someone who controls the folder can delete files or stop them syncing. PromptMason notices missing changes and puts back what it can, but it can't force your cloud storage to deliver. - **Checking who a person really is.** The approval-code call proves the PC you approve is the one in front of the person you're talking to. Call them on a number you already know is theirs. - **The primary owner being unexpectedly away.** Only the primary owner approves PCs, removes people and changes settings. If they're away without handing the role over, those things wait until they're back; editing carries on ([The primary owner](https://promptmason.ai/docs/primary-owner)). - **Losing everything.** If you lose every PC *and* your recovery kit, your personal library can't be recovered. Nobody else can open it, PromptMason included. In a team library, the primary owner can put you back after a quick call. If you're the primary owner, nobody can put you back: another owner exports the library and starts a new one ([The primary owner](https://promptmason.ai/docs/primary-owner#if-the-primary-owner-is-unexpectedly-away)). ## AI apps and team libraries An AI app you connect to PromptMason (a connected app) reads and changes your libraries through PromptMason. In a team library, the primary owner decides for everyone what AI apps can do: **Read only (recommended)**, **Read and change**, or **Nothing: AI apps can’t see it**, and how many changes an AI app can make per hour. Each person's own Connected apps setting still applies, and the stricter of the two wins. This setting limits AI agents and Chat. It doesn't limit a member's own AI assist or Evaluate. Each member chooses their provider there, so text from the library can still go to the provider a member picks. Changes an AI app makes show "via AI app" in History. See [Team libraries](https://promptmason.ai/docs/team-libraries#working-together) and [Control what connected apps can do](https://promptmason.ai/docs/agent-access). ## Something in the library folder was ignored You may see this in Notifications. It means PromptMason found a file in the library's folder that it doesn't trust, so it ignored it, or put the real one back. The library is fine. See [Sync problems](https://promptmason.ai/docs/sync-problems#something-in-the-library-folder-was-ignored) for each message. If it keeps happening, check who the folder is shared with in your cloud storage. ## Questions Email [support@promptmason.ai](mailto:support@promptmason.ai). --- How to help me: - Go one step at a time. After each step, ask what I see on screen before giving the next one. - Use the exact words on PromptMason’s buttons and screens, as the guide does. - Never ask me for my recovery code, my recovery kit file, a password or my invite line, and never ask me to paste them here. - Start by asking which step I’m on, or what I see now.