Configure {{site.ai_gateway}} passthrough for existing MCP Servers
Configure AI Gateway passthrough for existing MCP Servers to enable proxying and observability.
For this configuration to work properly, you need a Service and a Route with the following configuration:
services: - name: mcp-service url: http://host.docker.internal:3001 routes: - name: mcp-route paths: - /mcpCopied!
Before using the AI MCP Proxy plugin in passthrough-listener mode, you need an upstream MCP-compatible HTTP server.
For this example, use a simple Express-based MCP server that simulates a marketplace system. It provides read-only access to sample users and their orders through the following tools:
list_usersget_userlist_orderslist_orders_for_usersearch_orders
Run the following command to clone the repository, install dependencies, build the server, and start it:
git clone https://github.com/tomek-labuk/marketplace-acl.git && \
cd marketplace-acl && \
npm install && \
npm run build && \
node dist/server.js
When the server starts, it listens at http://localhost:3001/mcp.
Prerequisites
- A running MCP server
Add this section to your kong.yaml configuration file:
_format_version: "3.0"
plugins:
- name: ai-mcp-proxy
config:
mode: passthrough-listener
max_request_body_size: 1048576
Make the following request:
curl -i -X POST http://localhost:8001/plugins/ \
--header "Accept: application/json" \
--header "Content-Type: application/json" \
--data '
{
"name": "ai-mcp-proxy",
"config": {
"mode": "passthrough-listener",
"max_request_body_size": 1048576
},
"tags": []
}
'
Make the following request:
curl -X POST https://{region}.api.konghq.com/v2/control-planes/{controlPlaneId}/core-entities/plugins/ \
--header "accept: application/json" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $KONNECT_TOKEN" \
--data '
{
"name": "ai-mcp-proxy",
"config": {
"mode": "passthrough-listener",
"max_request_body_size": 1048576
},
"tags": []
}
'
Make sure to replace the following placeholders with your own values:
-
region: Geographic region where your Kong Konnect is hosted and operates. -
KONNECT_TOKEN: Your Personal Access Token (PAT) associated with your Konnect account. -
controlPlaneId: Theidof the control plane.
See the Konnect API reference to learn about region-specific URLs and personal access tokens.
echo "
apiVersion: configuration.konghq.com/v1
kind: KongClusterPlugin
metadata:
name: ai-mcp-proxy
namespace: kong
annotations:
kubernetes.io/ingress.class: kong
konghq.com/tags: ''
labels:
global: 'true'
config:
mode: passthrough-listener
max_request_body_size: 1048576
plugin: ai-mcp-proxy
" | kubectl apply -f -
Prerequisite: Configure your Personal Access Token
terraform {
required_providers {
konnect = {
source = "kong/konnect"
}
}
}
provider "konnect" {
personal_access_token = "$KONNECT_TOKEN"
server_url = "https://us.api.konghq.com/"
}
Add the following to your Terraform configuration to create a Konnect Gateway Plugin:
resource "konnect_gateway_plugin_ai_mcp_proxy" "my_ai_mcp_proxy" {
enabled = true
config = {
mode = "passthrough-listener"
max_request_body_size = 1048576
}
tags = []
control_plane_id = konnect_gateway_control_plane.my_konnect_cp.id
}
Add this section to your kong.yaml configuration file:
_format_version: "3.0"
plugins:
- name: ai-mcp-proxy
service: serviceName|Id
config:
mode: passthrough-listener
max_request_body_size: 1048576
Make sure to replace the following placeholders with your own values:
-
serviceName|Id: Theidornameof the service the plugin configuration will target.
Make the following request:
curl -i -X POST http://localhost:8001/services/{serviceName|Id}/plugins/ \
--header "Accept: application/json" \
--header "Content-Type: application/json" \
--data '
{
"name": "ai-mcp-proxy",
"config": {
"mode": "passthrough-listener",
"max_request_body_size": 1048576
},
"tags": []
}
'
Make sure to replace the following placeholders with your own values:
-
serviceName|Id: Theidornameof the service the plugin configuration will target.
Make the following request:
curl -X POST https://{region}.api.konghq.com/v2/control-planes/{controlPlaneId}/core-entities/services/{serviceId}/plugins/ \
--header "accept: application/json" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $KONNECT_TOKEN" \
--data '
{
"name": "ai-mcp-proxy",
"config": {
"mode": "passthrough-listener",
"max_request_body_size": 1048576
},
"tags": []
}
'
Make sure to replace the following placeholders with your own values:
-
region: Geographic region where your Kong Konnect is hosted and operates. -
KONNECT_TOKEN: Your Personal Access Token (PAT) associated with your Konnect account. -
controlPlaneId: Theidof the control plane. -
serviceId: Theidof the service the plugin configuration will target.
See the Konnect API reference to learn about region-specific URLs and personal access tokens.
echo "
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
name: ai-mcp-proxy
namespace: kong
annotations:
kubernetes.io/ingress.class: kong
konghq.com/tags: ''
config:
mode: passthrough-listener
max_request_body_size: 1048576
plugin: ai-mcp-proxy
" | kubectl apply -f -
Next, apply the KongPlugin resource by annotating the service resource:
kubectl annotate -n kong service SERVICE_NAME konghq.com/plugins=ai-mcp-proxy
Prerequisite: Configure your Personal Access Token
terraform {
required_providers {
konnect = {
source = "kong/konnect"
}
}
}
provider "konnect" {
personal_access_token = "$KONNECT_TOKEN"
server_url = "https://us.api.konghq.com/"
}
Add the following to your Terraform configuration to create a Konnect Gateway Plugin:
resource "konnect_gateway_plugin_ai_mcp_proxy" "my_ai_mcp_proxy" {
enabled = true
config = {
mode = "passthrough-listener"
max_request_body_size = 1048576
}
tags = []
control_plane_id = konnect_gateway_control_plane.my_konnect_cp.id
service = {
id = konnect_gateway_service.my_service.id
}
}
Add this section to your kong.yaml configuration file:
_format_version: "3.0"
plugins:
- name: ai-mcp-proxy
route: routeName|Id
config:
mode: passthrough-listener
max_request_body_size: 1048576
Make sure to replace the following placeholders with your own values:
-
routeName|Id: Theidornameof the route the plugin configuration will target.
Make the following request:
curl -i -X POST http://localhost:8001/routes/{routeName|Id}/plugins/ \
--header "Accept: application/json" \
--header "Content-Type: application/json" \
--data '
{
"name": "ai-mcp-proxy",
"config": {
"mode": "passthrough-listener",
"max_request_body_size": 1048576
},
"tags": []
}
'
Make sure to replace the following placeholders with your own values:
-
routeName|Id: Theidornameof the route the plugin configuration will target.
Make the following request:
curl -X POST https://{region}.api.konghq.com/v2/control-planes/{controlPlaneId}/core-entities/routes/{routeId}/plugins/ \
--header "accept: application/json" \
--header "Content-Type: application/json" \
--header "Authorization: Bearer $KONNECT_TOKEN" \
--data '
{
"name": "ai-mcp-proxy",
"config": {
"mode": "passthrough-listener",
"max_request_body_size": 1048576
},
"tags": []
}
'
Make sure to replace the following placeholders with your own values:
-
region: Geographic region where your Kong Konnect is hosted and operates. -
KONNECT_TOKEN: Your Personal Access Token (PAT) associated with your Konnect account. -
controlPlaneId: Theidof the control plane. -
routeId: Theidof the route the plugin configuration will target.
See the Konnect API reference to learn about region-specific URLs and personal access tokens.
echo "
apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
name: ai-mcp-proxy
namespace: kong
annotations:
kubernetes.io/ingress.class: kong
konghq.com/tags: ''
config:
mode: passthrough-listener
max_request_body_size: 1048576
plugin: ai-mcp-proxy
" | kubectl apply -f -
Next, apply the KongPlugin resource by annotating the httproute or ingress resource:
kubectl annotate -n kong httproute konghq.com/plugins=ai-mcp-proxy
kubectl annotate -n kong ingress konghq.com/plugins=ai-mcp-proxy
Prerequisite: Configure your Personal Access Token
terraform {
required_providers {
konnect = {
source = "kong/konnect"
}
}
}
provider "konnect" {
personal_access_token = "$KONNECT_TOKEN"
server_url = "https://us.api.konghq.com/"
}
Add the following to your Terraform configuration to create a Konnect Gateway Plugin:
resource "konnect_gateway_plugin_ai_mcp_proxy" "my_ai_mcp_proxy" {
enabled = true
config = {
mode = "passthrough-listener"
max_request_body_size = 1048576
}
tags = []
control_plane_id = konnect_gateway_control_plane.my_konnect_cp.id
route = {
id = konnect_gateway_route.my_route.id
}
}