Free checklist · LLM gateway security

The LLM Gateway Security Checklist

21 testable controls to check that your LLM gateway enforces least privilege, stops uncontrolled data exposure, and keeps audit-ready evidence before production rollout.

No paywall Vendor-neutral criteria Built for security and platform teams
  • Every model and tool request is authenticated through SSO or scoped keys
  • Apps never see raw provider keys
  • PII and prompt injection are caught inline, before the model
  • Rate limits and budgets fail closed

What the checklist covers:

21

Testable security controls for LLM, MCP, and agent traffic through a gateway

3

Control areas: identity and secrets, runtime guardrails, and audit and deployment

18

Must-have controls, flagged so you know what has to pass before rollout

4

Deployment models compared: VPC, on-premises, hybrid, and air-gapped

Inside the checklist

Download the checklist to get:

A working framework your security and platform teams can use to evaluate any LLM gateway, or to run your own gateway through a security review.

Download the Checklist

✓

The full 21-point LLM gateway security framework

Every control grouped by area, with the question to ask and a must-have or should-have priority.

✓

A three-step security review plan

Map access across apps, models, MCP servers, credentials, and data classes, enforce policy, then verify audit evidence.

✓

Guardrail and abuse-control criteria

What to test for PII redaction, prompt injection, content moderation, custom rules, rate limits, and budgets.

✓

Compliance and deployment requirements

The attestations, log ownership, tenant isolation, and deployment options to require for SOC 2, HIPAA, GDPR, and ITAR workloads.

Why it matters

The LLM Gateway Is Your New Security Boundary

LLM traffic now carries prompts, responses, tool calls, secrets, user context, and policy decisions across a new enterprise boundary. Every application that calls a model is sending potentially sensitive data to a third party, and every agent that calls a tool is acting with some level of privilege.

Without a gateway, each team wires up providers on its own. Raw API keys end up in environment variables and code repos. Nobody can say which user sent which data to which model. Guardrails are applied in some apps and not others, and a runaway script can burn through a month's budget overnight.

LLM Gateway Apps + users SSO · scoped key Identity + access RBAC · keys Guardrails PII · injection Limits + audit budgets · logs LLM providers keys held centrally MCP servers + tools same policy model request Runs in your VPC, on-premises, hybrid, or air-gapped · request logs stay in your cloud · exported to your SIEM

Every request passes the same checks in the same order. The checklist turns each stage into controls you can test.

An LLM gateway fixes this by putting one policy enforcement point in front of every model and tool. But not every gateway is built for security. Some are routing layers with authentication bolted on. Others run only as a hosted service, so your prompts and logs pass through someone else's infrastructure. Security reviews stall when nobody can show which controls are enforced and how.

What a secure LLM gateway looks like

Every request is authenticated through SSO, workload identity, or a scoped virtual key, and RBAC limits which models, tools, environments, and logs each user, team, and app can reach. Provider keys stay in the gateway or your secret manager, and rotate without redeploying apps.

PII, prompt injection, and unsafe content are caught inline, with custom and third-party guardrails for your own policies. Rate limits and budgets block requests predictably when they're exhausted. Every request is logged with identity, route, cost, and guardrail outcome, kept in your cloud, and exported to your SIEM. Teams are isolated from each other, and MCP servers and tools follow the same policy model as models.

Make the security review testable

"Do you support guardrails?" gets a yes from every vendor. "Is prompt injection blocked inline before the tool layer, with the outcome logged?" can be tested. The LLM Gateway Security Checklist turns gateway security into 21 controls like that, so your review produces evidence instead of assurances.

Preview

The three control areas in the LLM gateway security checklist

A sample of the controls in each area. The full checklist includes all 21, with priorities and evaluation questions.

Area 1 · 6 checks

Identity, access control, and secret protection

Every model and tool request goes through SSO, workload identity, or scoped gateway keys

RBAC restricts models, providers, tools, environments, and logs

Provider keys rotate without app redeploys

+3 more checks

Area 2 · 7 checks

Runtime guardrails and abuse controls

PII is detected and redacted inline in prompts and responses

Prompt injection is blocked before the model or tool layer

Budgets block requests automatically when exhausted

+4 more checks

Area 3 · 8 checks

Audit, compliance, and deployment ownership

Request logs capture identity, route, cost, guardrail outcomes, and errors

Logs stay in customer-controlled storage

Teams and business units are isolated at the gateway

+5 more checks

4.7

★★★★★

Gartner Peer Insights

Rated 4.7 on Gartner Peer Insights

Platform and security teams run TrueFoundry's AI Gateway for LLM, MCP, and agent traffic in production, with centralized access control, scoped keys, guardrails, budgets, rate limits, request logging, and customer-controlled deployment.

96%

of reviewers likely to recommend

4.9

ease of deployment and admin

3–4 ms

added gateway latency

LLM gateway security checklist FAQ

What is an LLM gateway security checklist?

An LLM gateway security checklist is a set of testable controls security teams use to evaluate whether the gateway in front of their models and tools enforces least privilege, prevents uncontrolled data exposure, and preserves audit-ready evidence before production rollout.

What security controls should an LLM gateway have?

At minimum: central authentication through SSO or scoped keys, RBAC over models, tools, and logs, provider key isolation with rotation, inline PII redaction, prompt injection defense, content moderation, rate limits and budgets that fail closed, full request logging with SIEM export, tenant isolation, and deployment options that keep data in your environment.

Why shouldn't applications hold raw LLM provider keys?

Raw provider keys spread across applications are hard to rotate, impossible to attribute, and give every app full provider access. A gateway keeps provider keys centrally, issues scoped virtual keys per application with expiration, and lets keys rotate without redeploying apps.

How does an LLM gateway defend against prompt injection?

The gateway inspects prompts and responses inline and blocks known prompt injection patterns before they reach the model or tool layer, using built-in detection, customizable rules, and third-party guardrail providers, with every guardrail outcome logged.

Can an LLM gateway run in my own VPC or an air-gapped environment?

It should, for sensitive workloads. The checklist treats customer-controlled deployment as a must-have. TrueFoundry's AI Gateway runs in your VPC, on-premises, hybrid, or air-gapped, with request logs kept in your own cloud storage.

Who should use the LLM gateway security checklist?

Security, platform engineering, and IAM teams evaluating an LLM or AI gateway, or preparing LLM, MCP, and agent traffic for a security review before production rollout.