> For the complete documentation index, see [llms.txt](https://docs.surgecardano.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.surgecardano.com/getting-started/how-non-custodial-works.md). # How non-custodial works Surge never holds your private keys and never signs a transaction for you. Every trade is built by Surge as an unsigned transaction, sent to your browser, signed there, and sent back to be broadcast to the Cardano network. This page explains what that means for you day to day. ### Who holds what | Thing | Where it lives | Who can use it | | -------------------------------------------- | ------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------- | | Your browser wallet's keys (Eternl, Lace, …) | In the wallet extension | Only you, via the extension's own prompts | | Your strategy wallets' keys | In an encrypted vault inside your browser (see [Wallets in Surge](/core-concepts/wallets-in-surge.md)) | Only your browser, and only after the Surge transaction guard and your approval settings allow it | | Your funds | In your wallets on the Cardano blockchain | Only whoever holds the matching key | | Surge's servers | Prices, strategy settings, order history, your wallet *addresses* and public keys | Never a private key | The one exception on Surge's side is the staking reward treasury: Surge holds a key for the wallet that pays out staking rewards, because those payouts come from Surge, not from you. It never touches your trading. See [Staking SURGE](/fees-tiers-and-staking/staking.md). ### What “you sign everything” means in practice 1. A trade is decided — by Surge's servers (a grid line was crossed, an arbitrage spread appeared, a rule level was reached, a Cadence order came due) or by your own browser (a DCA interval elapsed). 2. Surge builds the exact Cardano transaction and pushes it to your open browser tab. 3. Your browser checks the transaction against the [transaction guard](/core-concepts/signing-and-approvals.md) — it must not spend more than the strategy's budget, must not move tokens the strategy did not declare, and must return change to your wallet. 4. With "Automate signing" on (the default), that is the only check — nothing waits for you. If you have turned it off, a Signing Approval window shows you the full sending and receiving addresses and the maximum spend, and waits for you to click Approve. 5. Your browser signs with the strategy wallet's key and sends the signed transaction back to Surge, which broadcasts it. So you do not need to be at your computer while a strategy runs — but the Surge tab does need to stay open, because the signing happens there. For manual swaps, sends and funding, step 5 happens in your browser wallet extension instead, with the extension's own confirmation prompt. ### Why your strategy stops when you close the tab Because step 3–5 happen in your browser, a trade cannot be signed when the tab is closed, the laptop is asleep, or the connection to Surge has dropped. What each strategy does in that situation: | Strategy | Behaviour while the tab is closed | | ---------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Grid, Rule-based | The server pauses the strategy ("Paused — socket down") and resumes automatically when you reopen the tab. Any price crossings that happened meanwhile are ignored, not queued. | | Arbitrage | The server stops looking for opportunities for your strategy until you reopen the tab. An in-flight buy keeps waiting for its fill for up to 5 minutes, then is abandoned. | | DCA | The schedule itself runs inside your browser tab, so nothing happens at all until you reopen it. | | Cadence (Volume) | Orders keep coming due on the server but none are sent for signing while no tab is connected; any order more than 30 minutes past its time is skipped permanently, with no notification. | Two settings help: **Keep screen awake** (Settings → General) asks your operating system not to sleep the screen while a strategy is running, and the **socket status pill** in the header shows whether the live connection to Surge is up. Neither keeps a strategy running through a closed tab. ### What Surge can and cannot do with your funds Surge can only ever build transactions. It cannot spend anything without a signature from your browser, and the transaction guard limits what a signature can authorise. Surge cannot recover a strategy wallet if you lose its key file and the browser it was created in — see [Backing up strategy wallets](/core-concepts/wallets-in-surge.md#backing-up-and-restoring). --- # 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. 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