Kong AI Gateway vs Nonimo Gateway for personal data

Kong AI Gateway handles personal data through a plugin called AI Sanitizer. It sits next to Kong’s AI Proxy, replaces detected data with placeholders or synthetic values, and can optionally put the original values back into the response. Kong lists it as an Enterprise plugin, and it needs a separate service container beside the gateway.

Nonimo Gateway runs on your own servers. See plans and get in touch.

In Kong, the PII step is the AI Sanitizer plugin, inside the API gateway your team may already operate. If you do not run Kong and only need a pseudonymising layer in front of the OpenAI API, adopting a full API gateway for that is a lot of system, and Nonimo Gateway is the smaller path.

How the Kong AI Sanitizer works

Requests to model providers go through Kong’s AI Proxy or AI Proxy Advanced plugins, and AI Sanitizer cleans the request before AI Proxy sends it on. Detection runs in a separate container, kong/ai-pii-service, with language-specific images for English, Spanish, French, German, Italian, Japanese, Korean, Portuguese and Turkish. It works on self-managed Kong and on Konnect, Kong’s cloud platform.

It replaces values either with a placeholder, “a fixed placeholder pattern, PLACEHOLDER{i}”, or with synthetic values. Restoration is optional: “If restoration is enabled, the plugin restores the original request data in responses before returning them to the client.” Since 3.12 it can also sanitise responses or reject a request with an HTTP 400.

Where Kong stops

You need Kong, and the Enterprise offering. The plugin page says: “This plugin is only available as part of our AI Gateway Enterprise offering.” Enterprise pricing is custom. Kong offers a 30-day trial.

Streaming and tool calls are not described. Neither the plugin page nor the changelog says how sanitisation or restoration behaves when the answer is streamed, or what happens to personal data in tool-call arguments and results.

Only the latest message, since 3.14. In a chat, earlier messages are usually sent again with each request. Since 3.14 the plugin sanitises the latest message, not the whole body, so check what happens to personal data in the earlier turns your application resends.

National IDs are one generic category. Among its 18 categories, nationalid comes with examples (Aadhaar, PESEL, NRIC, social security and voter IDs) and no list of countries. A Spanish DNI, an Italian codice fiscale or a Brazilian CPF may or may not be caught; the custom category is there for your own patterns.

Skyflow also maintains a third-party Kong plugin that tokenises personal data in Skyflow’s service and re-identifies it in the answer, including in tool-call arguments. It needs Kong Gateway 3.15 or later and a Skyflow account, and for streaming it re-identifies “the full completion, which is then re-emitted as SSE”. We cover it in the Skyflow alternative guide.

Kong AI Gateway and Nonimo Gateway, side by side

	Kong AI Sanitizer	Nonimo Gateway
Runs as	Kong plugin plus kong/ai-pii-service container	On your own servers
Needs Kong	Yes, AI Gateway Enterprise offering	No
Replacement	Placeholder or synthetic	Stand-ins for each value
Real values back in the answer	Optional	Yes
Streaming	Not documented	Real values back in the answer
National IDs	Generic nationalid, no country list	National documents and numbers of each country covered
API	Through Kong’s AI Proxy	OpenAI-compatible: change base_url

How Nonimo Gateway does it

Nonimo Gateway is for teams that do not run Kong, or do not want to adopt a full API gateway just to pseudonymise prompts. It runs on your own servers and has an OpenAI-compatible API, so the change in your code is the base URL:

from openai import OpenAI

client = OpenAI(
    base_url="https://gateway.your-company.internal/v1",
    api_key="sk-...your own OpenAI key...",
)

It replaces personal data in what goes out and restores the real values in the response. It recognises the national documents and numbers of each country it serves, for example the Spanish DNI, NIE and NIF, the German Steuer-ID, the French NIR, the Italian codice fiscale, the Brazilian CPF and the Mexican RFC and CURP. You keep your own OpenAI key, and if you route through LiteLLM there is a plugin for it. Plans and prices are on the Nonimo Gateway page.

Reversible replacement is pseudonymisation, and the data stays personal data for whoever holds the key; our guides on what HIPAA and the CCPA require of de-identification and on what to redact before you paste a document into an AI explain the difference.

If you want PII protection in front of the OpenAI API without taking on Kong, Nonimo Gateway is built for that. See plans and get in touch. For the wider market, see the overview of PII redaction software or the comparisons with Cloudflare AI Gateway and LiteLLM guardrails.

Sources

• Kong, AI Sanitizer plugin. Enterprise only, AI Proxy, kong/ai-pii-service, modes, restoration, 18 categories and the nationalid examples, nine language images, supported deployments.
• Kong, AI Sanitizer changelog. Response sanitising and block mode in 3.12, latest-message-only in 3.14.
• Kong, pricing. AI Sanitizer among Enterprise plugins, custom Enterprise pricing, 30-day trial.
• Kong, Skyflow AI Data Control plugin. Third-party, Kong 3.15 minimum, tool-call re-identification, buffered streaming.

All checked 20 October 2026.

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This page is for information. Product details of other vendors were checked on their official pages on 20 October 2026 and can change.