How to Transform REST APIs into MCP Services with Higress, Nacos, and Spring AI

Environment preparation

Create an isolated Docker network for all components:

docker network create mcp

Deploy Higress

Run the all‑in‑one Higress image, expose the management and data ports, and attach it to the mcp network:

docker run -d --rm --name higress-ai -v ${PWD}:/data \
    -p 8001:8001 -p 8080:8080 -p 8443:8443 \
    --network mcp \
    higress-registry.cn-hangzhou.cr.aliyuncs.com/higress/all-in-one:latest

Deploy Redis

Redis stores MCP server state. Deploy it on the same network:

docker run -d --rm --name higress-redis -p 6379:6379 \
    --network mcp \
    higress-registry.cn-hangzhou.cr.aliyuncs.com/higress/redis-stack-server:7.4.0-v3

Configure MCP Server in Higress

Edit the ConfigMap that Higress reads (e.g. ./configmaps/higress-config.yaml) to enable the MCP server and point it to Redis:

apiVersion: v1
kind: ConfigMap
metadata:
  name: higress-config
  namespace: higress-system
data:
  higress: |-
    mcpServer:
      sse_path_suffix: /sse
      enable: true
      redis:
        address: higress-redis:6379
    downstream: {}

On non‑Linux hosts the ConfigMap changes may not be applied immediately; restart the higress-ai container to force a reload.

Deploy Nacos (standalone)

Run a single‑node Nacos instance and expose its management ports:

docker run --name nacos \
    -e MODE=standalone \
    -e NACOS_AUTH_TOKEN=your_token_base64 \
    -e NACOS_AUTH_IDENTITY_KEY=your_key \
    -e NACOS_AUTH_IDENTITY_VALUE=your_value \
    -p 8081:8080 -p 8848:8848 -p 9848:9848 \
    --network mcp -d \
    nacos-registry.cn-hangzhou.cr.aliyuncs.com/nacos/nacos-server:v3.0.1

Convert a REST API to an MCP service

In the Nacos console, create an MCP Server under the “MCP Registry” section. Add a Tool named get_weather with the following request template:

{
  "requestTemplate": {
    "url": "/v3/weather/weatherInfo?key=yourkey",
    "argsToUrlParam": true,
    "method": "GET"
  }
}

Publish the tool as the latest version. The service becomes reachable through Higress via the SSE endpoint, for example:

http://{HOST}:8080/mcp/amap/sse

Dynamic configuration with Nacos

Starting with Nacos 3.0.1, MCP templates can reference Nacos configuration items, allowing runtime updates without redeploy.

Create a ConfigMap named amap_key in the data group:

{
  "data": "your_key"
}

Reference this key inside the MCP template (e.g. ${amap_key}). Updating the ConfigMap at runtime changes the value used by the MCP service, enabling token rotation or other parameter adjustments on the fly.

Spring AI Alibaba integration

Clone the Spring AI Alibaba examples repository and run the Nacos MCP example, which automatically registers an MCP service in Nacos:

git clone https://github.com/springaialibaba/spring-ai-alibaba-examples.git
cd spring-ai-alibaba-examples/spring-ai-alibaba-mcp-example/spring-ai-alibaba-mcp-nacos-example/server/mcp-nacos-registry-example
# Edit src/main/resources/application.yml to set your Nacos username and password
mvn spring-boot:run

The application registers the MCP service; Higress discovers it and creates transparent proxy rules, so the service can be accessed through Higress without code changes.

Verification

1. Access the SSE endpoint to confirm the service works. 2. Modify the amap_key ConfigMap to an invalid value and re‑access the endpoint; the request should fail, demonstrating that dynamic configuration changes are applied immediately. 3. Observe Higress logs or use a client to verify that the proxy rules are generated automatically for the registered MCP service.