---
layout: docs
page_title: Use JWTs to verify requests to API gateways on virtual machines
description: Learn how to use JSON web tokens (JWT) to verify requests from external clients to listeners on an API gateway.
---

# Use JWTs to verify requests to API gateways on virtual machines

This topic describes how to use JSON web tokens (JWT) to verify requests to API gateways on virtual machines (VM). If your services are deployed to Kubernetes-orchestrated containers, refer to [Use JWTs to verify requests to API gateways on Kubernetes](/consul/docs/connect/gateways/api-gateway/secure-traffic/verify-jwts-k8s).

<EnterpriseAlert> This feature is available in Consul Enterprise. </EnterpriseAlert>

## Overview

You can configure API gateways to use JWTs to verify incoming requests so that you can stop unverified traffic at the gateway. You can configure JWT verification at different levels:

- Listener defaults: Define basic defaults that apply to all routes attached to a listener.
- HTTP route-specific settings: You can define JWT authentication settings for specific HTTP routes. Route-specific JWT settings override default configurations.
- Listener overrides: Define override settings that take precedence over default and route-specific configurations. This enables you to set enforceable policies for listeners.

Complete the following steps to use JWTs to verify requests:

1. Define a JWTProvider that specifies the JWT provider and claims used to verify requests to the gateway.
1. Configure default and override settings for listeners in the API gateway configuration entry.
1. Define route-specific JWT verification settings as filters in the HTTP route configuration entries.
1. Write the configuration entries to Consul to begin verifying requests using JWTs.

## Requirements

- Consul 1.17 or later
- JWT details, such as claims and provider

## Define a JWTProvider

Create a JWTProvider config entry that defines the JWT provider to verify claims against.
In the following example, the JWTProvider CRD contains a local JWKS. In production environments, use a production-grade JWKs endpoint instead.

<CodeBlockConfig filename="jwt-provider.hcl">

```hcl
Kind = "jwt-provider"
Name = "local"

Issuer = "local"

JSONWebKeySet = {
    Local = {
        JWKS="<JWKS-Key>"
    }
}
```

</CodeBlockConfig>

For more information about the fields you can configure in this CRD, refer to [`JWTProvider` configuration reference](/consul/docs/connect/config-entries/jwtprovider).

## Configure default and override settings

Define default and override settings for JWT verification in the [API gateway configuration entry](/consul/docs/connect/gateways/api-gateway/configuration/api-gateway).

1. Add a `default.JWT` block to the listener that you want to apply JWT verification to. Consul applies these configurations to routes attached to the listener. Refer to the [`Listeners.default.JWT`](/consul/docs/connect/config-entries/api-gateway#listeners-default-jwt) configuration reference for details.
1. Add an `override.JWT` block to the listener that you want to apply JWT verification policies to. Consul applies these configurations to all routes attached to the listener, regardless of the `default` or route-specific settings. Refer to the [`Listeners.override.JWT`](/consul/docs/connect/config-entries/api-gateway#listeners-override-jwt) configuration reference for details.
1. Apply the settings in the API gateway configuration entry. You can use the [`/config` API endpoint](/consul/api-docs/config#apply-configuration) or the [`consul config write` command](/consul/commands/config/write).

The following examples configure a Gateway so that every request coming through the listener must meet these conditions:
- The request must be signed by the `local` provider
- The request must have a claim of `role` with a value of `user` unless the HTTPRoute attached to the listener overrides it

<CodeBlockConfig filename="gateway.hcl">

```hcl
Kind = "api-gateway"
Name = "api-gateway"
Listeners = [
  {
    Name     = "listener-one"
    Port     = 9001
    Protocol = "http"
    Override = {
      JWT = {
        Providers = [
          {
            Name = "local"
          }
        ]
      }
    }
    default = {
      JWT = {
        Providers = [
          {
            Name = "local"
            VerifyClaims = [
              {
                Path  = ["role"]
                Value = "pet"
              }
            ]
          }
        ]
      }
    }
  }
]
```

</CodeBlockConfig>

## Configure verification for specific HTTP routes

Define filters to enable route-specific JWT verification settings in the [HTTP route configuration entry](/consul/docs/connect/config-entries/http-route).

1. Add a `JWT` configuration to the `rules.filter` block. Route-specific configurations that overlap the [default settings ](/consul/docs/connect/config-entries/api-gateway#listeners-default-jwt) in the API gateway configuration entry take precedence. Configurations defined in the [listener override settings](/consul/docs/connect/config-entries/api-gateway#listeners-override-jwt) take the highest precedence.
1. Apply the settings in the API gateway configuration entry. You can use the [`/config` API endpoint](/consul/api-docs/config#apply-configuration) or the [`consul config write` command](/consul/commands/config/write).

The following example configures an HTTPRoute so that every request to `api-gateway-fqdn:3002/admin` must meet these conditions:
- The request be signed by the `local` provider.
- The request must have a `role` claim.
- The value of the claim must be `admin`.

Every other request must be signed by the `local` provider and have a claim of `role` with a value of `user`, as defined in the Gateway listener.

<CodeBlockConfig filename="http-route.hcl">

```hcl
Kind = "http-route"
Name = "api-gateway-route"
Parents = [
  {
    SectionName = "listener-one"
    Name        = "api-gateway"
    Kind        = "api-gateway"
  },
]
Rules = [
  {
    Matches = [
      {
        Path = {
          Match = "prefix"
          Value = "/admin"
        }
      }
    ]
    Filters = {
      JWT = {
        Providers = [
          {
            Name = "local"
            VerifyClaims = [
              {
                Path  = ["role"]
                Value = "admin"
              }
            ]
          }
        ]
      }
    }
    Services = [
      {
        Name = "admin-service"
      }
    ]
  },
  {
    Matches = [
      {
        Path = {
          Match = "prefix"
          Value = "/"
        }
      }
    ]
    Services = [
      {
        Name = "user-service"
      }
    ]
  },
]
```

</CodeBlockConfig>
