> For the complete documentation index, see [llms.txt](https://docs.arcan.finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.arcan.finance/protocol/gateway.md). # Gateway The gateway is the front door between an app, Robinhood, and the coprocessors. It does not run FHE and it does not hold user balances. ## Jobs * Accept an encrypted input and route the proof check to the input verifier * Track which ciphertext belongs on the host after a coprocessor finishes * Carry a decrypt request to the key service and back to the allowed user * Move a ciphertext when a contract on the host must consume a handle that was produced elsewhere ## What users call Most apps never address the gateway directly. The SDK and the contract do. * Encrypt and send a transaction to the token contract on Robinhood * Read a handle from the contract * Ask the SDK to decrypt The gateway is the path those calls take once they leave the device. ## Consensus on results Coprocessors must agree on the output ciphertext for a handle. The gateway waits for that agreement before it treats the result as final. Agreement is on the ciphertext, which is public as bytes and still unreadable as a number. ## Bridging a ciphertext A handle is meaningful where it was created. To use it from another context, the gateway carries the ciphertext and the access-list rights, and the destination records a new handle. It does not decrypt in the middle. --- # 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 following URL with the `ask` and `goal` query parameters: ``` GET https://docs.arcan.finance/protocol/gateway.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `build a script that syncs our docs to a CMS` lets GitBook tailor the answer to that use case. 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.