# What is a PII gateway? explainer A PII gateway is a control point between your systems and a large language model. It finds the personal data in what you send — names, national IDs, health and bank numbers, addresses, contact details — replaces each value with a token before the model provider receives it, and puts the real values back into the answer. OBVELO is a PII gateway hosted in the EU. [Start free](https://app.obvelo.com/?plan=free) [Try the live demo](https://obvelo.com/#demo) [Read the docs](https://obvelo.com/docs/) why a gateway ## Why mask personal data before it reaches the LLM Prompts, attachments and tool results carry the people your work is about: a customer in a ticket, a patient in a letter, an employee in a spreadsheet. Once a value has reached the model provider, nothing on your side can call it back. A gateway stands where that traffic already passes, so the value is replaced before it leaves. one place ### One control point for every path Applications, agents, files and people in a chat window go through one engine and one set of rules. Masking stays on the gateway, so a fix there reaches every installation the same day. context ### The model keeps the context A token rather than a black box: the sentence keeps its shape, so the model still reads who did what to whom — it just does not learn the name. The same value keeps the same token everywhere in the request. audit ### An audit trail without the content Which account, which key, which tool, allowed or refused — never the content itself. It answers who sent this and who approved this. redaction, anonymisation, pseudonymisation ## PII redaction for LLMs, done as pseudonymisation Three words are used for keeping personal data away from a model. They are not the same thing, and only one of them gives you the answer back with the real names in it. redaction ### The value is removed A black box or a deleted word. The model does not learn the name — and nothing can put it back into the answer, so a reply drafted for the person no longer says who it is for. anonymisation ### Nobody can tell who it was Not even you: there is nothing left to turn the text back into the document you sent. It suits statistics more than a letter you still have to send. pseudonymisation ### A token you can turn back What OBVELO does. Each value becomes a token such as [Person 1]; you keep the mapping, so the answer comes back with the real values in place. Pseudonymisation, not anonymisation. european by construction ## What makes it a European PII gateway - **Hosted in the EU.** Hosting and every sub-processor are in the EU or EEA, and every sub-processor is entered in our register of processing activities before it is used. - **Detection that cannot call out.** The name model runs in a container that holds no network permission — not “does not use the network”, but cannot. - **Nothing from request content stored.** The data plane stores nothing from request content; the control plane stores the account, the plan and usage in numbers, and never sees content. In a deployment in your own infrastructure, the gateway also keeps a content log for up to 30 days on your servers, encrypted with your key and readable only by your administrators; we never see it. - **No vault on our side.** The mapping that turns tokens back into the real values travels with your request and stays with you. - **Your provider, your credentials.** Traffic goes to your model provider on your own credentials. We do not call a model on our contract. OBVELO lowers the personal data your model provider receives and gives you a control point with an audit trail. The detail is on the [security page](https://obvelo.com/security/). where it sits ## Where a PII gateway fits in your AI stack llm proxy ### In front of the API you already call OpenAI chat and responses, Anthropic messages, Gemini contents — Mistral and compatibility gateways speak the chat shape. Point your client at the gateway and add one header; streaming and tool calls included. [Connect it](https://obvelo.com/product/#connect). sdk ### In your own code SDKs for TypeScript, Python and .NET wrap the model client you already use. Your provider key never reaches us, and the values come back in your process. [The SDKs](https://obvelo.com/docs/#sdks). agents and mcp ### Between an agent and its tools Tool results are masked value by value; IDs, threads and cursors pass through, so the agent keeps working. A connector gives any MCP client tools that mask and restore. [Agents and files](https://obvelo.com/product/#beyond). browser ### In the chat window The browser add-on masks what a person types or pastes into an AI chat before it is sent, and puts the real names back into the answer on screen. [The add-on](https://obvelo.com/extension/). files ### Inside the attachment With file masking on, a docx, xlsx, pptx, csv or txt comes back masked and still opens — authors and comments included. [Files and attachments](https://obvelo.com/attachments/). what it finds ## PII detection across jurisdictions 668 detection rules in 19 categories find national, tax and social-security numbers, health and bank numbers, addresses and contact details across 52 jurisdictions, and a name model finds the people. Your own lists of people and companies travel with the request and are stored nowhere. For the documents a sector writes there are presets: see [healthcare](https://obvelo.com/healthcare/) and [public administration](https://obvelo.com/public-administration/). ## Personal data stays with you. The question goes to the model. See it on the live gateway, or start free — the free plan needs no card. [Start free](https://app.obvelo.com/?plan=free) [Contact](https://obvelo.com/contact/) --- OBVELO is a risk mitigation and control point. © 2026 OBVELO · all example data on this site is invented Page: https://obvelo.com/pii-gateway/