AI agent security

Best AI security solution for fintech

The useful fintech control inspects financial PII in-process, gates the transfer or refund at the tool boundary, and records who did what for the audit. A cloud scanner that reads a prompt with a card number becomes a recipient of cardholder data and can widen your PCI scope. In-code enforcement keeps the raw value local and produces per-action evidence.

6 min read
In short: The useful fintech control inspects financial PII in-process, gates the transfer or refund at the tool boundary, and records who did what for the audit. A cloud scanner that reads a prompt with a card number becomes a recipient of cardholder data and can widen your PCI scope. In-code enforcement keeps the raw value local and produces per-action evidence.

What is the best AI security solution for fintech?

The useful answer for fintech is not a product tier. It's a set of controls that inspect financial data in your process, gate money-moving actions before they take effect, and record an attributable decision for the audit. A fintech agent can read an account, move funds, or approve a limit, so the control has to sit where those actions happen: in the application code, in the path of the action, with the account and the amount in scope.

A scanner that exports the prompt to classify it, or a proxy that sees the request but not the business context, misses the part that matters for finance – whether this caller may move this money right now. For the layer model behind this, see what's the best AI security provider for enterprises, and for the regulated-data version of the argument, see the best AI security for healthcare and regulated industries.

Why does financial data need in-process inspection?

Card numbers, account numbers, and balances are the data a fintech application handles by default, and where you inspect them decides your compliance scope. A cloud service that reads a prompt containing a card number becomes a recipient of cardholder data, which can pull that vendor into your PCI DSS scope and add a processor under the GLBA Safeguards Rule.

In-process detection keeps the raw value inside your environment and lets only the matched entity types leave. That's the same reason to keep security inspection local. Run a sensitiveInfo check on any route that accepts free text headed for a model or a log:

import arcjet, { sensitiveInfo } from "@arcjet/next";
const aj = arcjet({
key: process.env.ARCJET_KEY!,
rules: [
sensitiveInfo({
mode: "LIVE",
deny: ["CREDIT_CARD_NUMBER", "EMAIL"],
}),
],
});
export async function POST(req: Request) {
const body = (await req.json()) as { message?: unknown };
if (typeof body.message !== "string") {
return new Response("Expected a message string.", { status: 400 });
}
const message = body.message;
const decision = await aj.protect(req, { sensitiveInfoValue: message });
if (decision.isDenied()) {
return new Response("Remove account or card details.", { status: 400 });
}
return Response.json({ ok: true });
}

For the full field-level treatment, see PII detection for AI applications.

How do you gate money-moving agent actions?

Detection tells you what's in the text. It doesn't decide whether an action is allowed to run. In fintech the consequential step is the transfer, the refund, or the limit change, so you need a deterministic check immediately before that side effect, with the user, the amount, and the target account in scope.

Model output filtering can't do this, because an unsafe transfer can come from a valid-looking tool call. The gate belongs in your code, at the tool boundary, and it fails closed: if the check can't run, the action doesn't. This is the pattern in how to add human review and approval gates to AI agent actions and, more generally, AI agent runtime security.

How do you stop automated abuse of financial APIs?

Fintech endpoints attract credential stuffing on login, enumeration on account lookups, and card testing on payment routes. These arrive as well-formed requests, so a syntax check passes them. You need identity-aware rate limits and bot detection on the abused operation, not only at the perimeter.

Put the limit on the account or API key rather than the IP, because a distributed attacker rotates addresses while keeping one target. For the reasoning and the algorithms, see rate limiting algorithms and what is API abuse.

What audit evidence do fintech regulators expect?

Financial regulators and auditors ask for records, not adjectives. A control that helps here writes an attributable decision – who acted, on what, and what the system allowed or denied – that survives into your logs:

  • PCI DSS 4.0 requirement 6.4.2 expects an automated technical solution that detects and prevents web attacks in front of public-facing applications.
  • The GLBA Safeguards Rule expects access controls and monitoring on customer financial information.
  • SOC 2 Type 2 is the common, checkable report a counterparty asks for.
  • NYDFS 23 NYCRR 500 and SOX add access-control and change-control expectations for covered firms.

A control in your application code can produce that evidence per action. Read producing compliance evidence for AI agent activity for the shape of the record.

What should you ask an AI security vendor for fintech?

Ask for the report, not the label. SOC 2 Type 2, ISO 27001, and PCI DSS responsibilities are separate claims that are often implied together. Ask which controls run in your process and which send the request elsewhere, because that answer sets your data-residency and PCI scope. Ask what the control does when its dependency is slow or down, because a payment path that fails open silently is worse than one that fails closed on purpose.

An architecture that keeps inspection local and enforcement in code is a claim you can verify by reading your own request path. A certification logo is not.

How does this relate to AI agent runtime security?

Fintech is the strict case of the general pattern. The same four jobs apply everywhere an agent acts: inspect untrusted data locally, gate the consequential action, limit resource and spend abuse, and log an attributable decision. Finance raises the stakes on each and adds named regulations, but the controls are the ones in AI agent runtime security and runtime security for LLM applications.

Start with local detection on the routes that carry financial data, add the action gate on the money-moving tool, then layer rate limits and budgets. Ship each control in the same pull request as the feature it protects, so security stays part of the development loop instead of a proxy hop bolted on later.

Frequently asked questions

What is the best AI security solution for fintech?

A set of controls rather than a product tier: inspect financial data in your process, gate money-moving actions before they take effect with the user and amount in scope, limit automated abuse of financial endpoints, and log an attributable decision for the audit.

Does an AI security vendor pull into my PCI DSS scope?

A cloud service that reads a prompt containing cardholder data becomes a recipient of that data, which can bring the vendor into your PCI DSS scope. In-process inspection keeps the raw value inside your environment, so only the matched entity types leave.

How do you stop an AI agent making an unauthorized transfer?

Put a deterministic check immediately before the money-moving tool call, with the user, amount, and target account in scope, and fail closed. Model output filtering can't do this because an unsafe transfer can come from a valid-looking tool call.

What compliance evidence do fintech auditors expect?

Attributable records: who acted, on what, and what the system allowed or denied. This supports PCI DSS 4.0 requirement 6.4.2, the GLBA Safeguards Rule, SOC 2 Type 2, and NYDFS 23 NYCRR 500. A control in your application code can produce that evidence per action.

AI runtime security in your code

Protect your AI agent workflows with Arcjet

Get allow, deny, and redact on agent actions before the side effect.