> For the complete documentation index, see [llms.txt](https://docs.usance.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.usance.xyz/understand-it/security.md). # Security and authority Usance is **non-custodial**: it never holds your keys or your assets, and every action is a transaction you sign yourself. The risk is granting more authority than you meant to. Usance itself can never take anything, because it is non-custodial, but you can grant more than you intended. Five different things get loosely called "connected," and they are not the same. ## The five grants | Grant | What it lets happen | When it ends | | --------------------- | -------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------- | | **Wallet connection** | A site can *see* your address and *ask* you to sign. It cannot move anything. | When you disconnect, though the site can reconnect silently on your next visit. | | **App session** | Proves you control the address (a signature), so Usance shows *your* account. Kept only in your browser. | When you sign out, or clear the browser. Never leaves your device. | | **Token allowance** | Lets a specific contract move up to a specific amount of one token. | When you set it back to zero. Usance requests exact amounts, not unlimited ones. | | **A mandate** | Lets a named agent act on your account, inside limits you sign. | When it expires or you revoke it. Revocation is immediate and permanent. | | **A transaction** | Does one specific thing, once. | Immediately. It grants nothing ongoing. | Two of these, allowances and mandates, **outlive closing the browser**, because they live on-chain rather than in a tab. Disconnecting a site does not repay a debt, close a position, or revoke a mandate. ## A mandate A mandate is a signed, bounded delegation. It can only ever **narrow** what the protocol already allows, never widen it. When you sign one you see, before your wallet opens, exactly which actions it grants, the caps, the expiry, and the agent it authorises. The load-bearing rule: **withdrawal of collateral is not a delegable action.** There is no withdrawal action in the mandate vocabulary at all, so an agent cannot move your collateral out even if you signed a mandate granting everything. A mandate can let an agent repay debt or add collateral, actions that reduce risk, and nothing that removes value from your account. Revocation is **terminal**. The registry has no un-revoke function on any path. Re-authorising an agent means signing a new mandate. ## Sentinels: automation you can bound A **Sentinel** is a bounded autonomous agent built on this mandate model, for example one that repays a little debt to hold a safety buffer when your account approaches its limit. The guarantees are the same ones the mandate gives, made explicit: * Every action is checked as `AllowedAction = ProtocolAllows ∧ MandateAllows`, re-read against live state before it submits. AI may *observe* and *propose*, and deterministic policy and your signed mandate *decide*. * A compromised agent still cannot exceed the mandate, cannot borrow or trade, cannot withdraw collateral, and cannot widen its own permissions. * You can pause or revoke it at any time, and revocation is immediate and permanent. ## Verifying instead of trusting Every financial action writes a public receipt that cites the transactions behind it. Anyone can open a receipt and check it against the chain without a wallet, so a counterparty can confirm a claim without taking your word, or Usance's. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.usance.xyz/understand-it/security.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.