AGS Extend SDK MCP Server

This Model Context Protocol (MCP) server exposes Extend SDK functions and models as additional context to language models. It helps AI coding assistants and other MCP clients to answer questions and generate Extend SDK code by providing the following tools.

• search-symbols – Search for symbols (functions and models) by name, tags, description (fuzzy)
• describe-symbols – Get detailed information about specific symbols by their IDs
• create-extend-app – Prompt template for creating Extend app projects

Quickstart

Prerequisites

• Cursor
• Docker

[!NOTE] The instructions below can be adapted for other MCP clients as well e.g. Claude Desktop, Gemini CLI, and Visual Studio Code.

Alternative 1: Using STDIO transport (default)

1. Pull the AGS Extend SDK MCP Server container image. For example, with image tag 2026.1.0.

   docker pull ghcr.io/accelbyte/ags-extend-sdk-mcp-server:2026.1.0
   

2. Switch to your project directory and create .cursor/mcp.json with the following content.

   {
     "mcpServers": {
       "extend-sdk-mcp-server": {
         "command": "docker",
         "args": [
           "run",
           "-i",
           "--rm",
           "-e",
           "CONFIG_DIR",
           "ghcr.io/accelbyte/ags-extend-sdk-mcp-server:2026.1.0"
         ],
         "env": {
           "CONFIG_DIR": "config/go"
         }
       }
     }
   }
   

   The CONFIG_DIR value above is for Go Extend SDK. For other Extend SDK languages, see here.

3. Open your project directory in Cursor and open File > Preferences > Cursor Settings, In Cursor Settings, click MCP, and make sure extend-sdk-mcp-server is enabled.

Alternative 2: Using Streamable HTTP transport

1. Pull the AGS Extend SDK MCP Server container image. For example, with image tag 2026.1.0.

   docker pull ghcr.io/accelbyte/ags-extend-sdk-mcp-server:2026.1.0
   

2. Start the MCP server with streamable HTTP transport.

   docker run -p 3000:3000 \
     -e TRANSPORT=http \
     -e PORT=3000 \
     -e CONFIG_DIR=config/go \
     -e NODE_ENV=production \
     -e LOG_LEVEL=info \
     ghcr.io/accelbyte/ags-extend-sdk-mcp-server:2026.1.0
   

   The CONFIG_DIR value above is for Go Extend SDK. For other Extend SDK languages, see here.

3. Switch to your project directory and create .cursor/mcp.json with the following content.

   {
     "mcpServers": {
       "extend-sdk-mcp-server": {
         "url": "http://localhost:3000/"
       }
     }
   }
   

4. Open your project directory in Cursor and open File > Preferences > Cursor Settings, In Cursor Settings, click MCP, and make sure extend-sdk-mcp-server is enabled.

[!IMPORTANT] Use the ghcr.io/accelbyte/ags-extend-sdk-mcp-server image tag that matches your AGS version. See the available image tags here.

Sample prompts

In Cursor, press CTRL+L and try the following prompts. You should see that the tools provided by this MCP server are used. Give permission to execute the tools when requested.

• Search symbols: Search for symbols related to 'user'
• Get symbol details: Describe the 'AdminCreateUser@iam' and 'User@iam' symbols

[!TIP] When coding using this MCP server, we recommend to start from an Extend SDK getting started sample project or an Extend app template project instead of a blank project. Add the necessary context, such as specific source code files, to help getting better results.

Environment Variables

• TRANSPORT: The MCP server transport (valid values: stdio, http, streamableHttp, default: stdio)
• PORT: HTTP server port if TRANSPORT is http (default: 3000)
• CONFIG_DIR: Directory of YAML config files (recursive, default: config/go)
  • For Extend SDK C#: config/csharp
  • For Extend SDK Go: config/go
  • For Extend SDK Java: config/java
  • For Extend SDK Python: config/python
• LOG_LEVEL: Logging level (valid values: debug, info, warn, error, default: info)
• ALLOWED_ORIGINS: Comma-separated list of allowed origins for HTTP transport (optional)
• NODE_ENV: Environment (valid values: development, production) (optional, used by Express for HTTP transport)

Development

Prerequisites

• Bash
• Curl
• Docker
• Makefile
• Node.js 18+
• pnpm

Install dependencies

pnpm install

Start the MCP server for development

With the default STDIO transport

pnpm dev

With streamable HTTP transport

TRANSPORT=http pnpm dev 

Build the MCP server

pnpm build

Start the MCP server after build

With the default STDIO transport

pnpm start

With streamable HTTP transport

TRANSPORT=http pnpm start

Build the MCP server container image

docker build -t extend-sdk-mcp-server:latest .

Release

Push the MCP server container image to container registry

# Setup variables

GHCR_USERNAME=<your-username>
GHCR_PASSWORD=<your-password>
IMAGE_TAG=2026.1.0    # Matches AGS release, bump patch version for hotfix

# Prepare builder

docker buildx inspect extend-sdk-mcp-server-builder || docker buildx create --name extend-sdk-mcp-server-builder --use

# Login, build, and push multiarch image

docker login --username ${GHCR_USERNAME --password $GHCR_PASSWORD}
docker buildx build -t ghcr.io/accelbyte/ags-extend-sdk-mcp-server:${IMAGE_TAG} --platform linux/amd64,linux/arm64 --push .

# Clean up builder

docker buildx rm --keep-state extend-sdk-mcp-server-builder

Testing

1. Start the MCP server with HTTP transport.

2. Initialize the MCP connection.

   curl -N -H "Accept: application/json, text/event-stream" \
       -H "Content-Type: application/json" \
       -X POST \
       -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"test-client","version":"1.0.0"}}}' \
       http://localhost:3000/
   

3. List available tools.

   curl -N -H "Accept: application/json, text/event-stream" \
       -H "Content-Type: application/json" \
       -X POST \
       -d '{"jsonrpc":"2.0","id":2,"method":"tools/list","params":{}}' \
       http://localhost:3000/
   

4. Test the search tool.

   curl -N -H "Accept: application/json, text/event-stream" \
       -H "Content-Type: application/json" \
       -X POST \
       -d '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"search-symbols","arguments":{"query":"user"}}}' \
       http://localhost:3000/
   

5. Test describe model.

   curl -N -H "Accept: application/json, text/event-stream" \
       -H "Content-Type: application/json" \
       -X POST \
       -d '{"jsonrpc":"2.0","id":4,"method":"tools/call","params":{"name":"describe-symbols","arguments":{"ids":["User@iam"]}}}' \
       http://localhost:3000/