AGS Extend SDK MCP Server

A Model Context Protocol (MCP) server that gives AI assistants (VS Code Copilot, Cursor, Claude, Gemini, Antigravity) the AccelByte Extend SDK as additional context — so they can answer questions about the SDK and generate correct Extend SDK code.

What It Does

• Search Extend SDK symbols (functions and models) by name, tags, or description (fuzzy matching)
• Describe specific symbols — parameters, fields, imports, examples, return types, required permissions
• Scaffold a new Extend app from a template repository via the `create-extend-app` prompt

It serves SDK reference for four languages — C#, Go, Java, and Python. You pick the language per connection through the URL path (see Choose your language).

AccelByte hosts the Extend SDK MCP Server for you — you don't need to install or run anything locally. Just point your AI assistant at the hosted MCP URL for your language. There's no sign-in: the server only exposes read-only SDK reference data. Prefer to run it yourself? See Running Locally & Self-Hosting.

Quick Install

Paste this into your AI coding assistant — it will fetch the install guide, ask you a couple of questions, and configure everything for you:

Install the AGS Extend SDK MCP server for me. Fetch and follow the instructions at
https://raw.githubusercontent.com/AccelByte/ags-extend-sdk-mcp-server/refs/heads/master/INSTALL.md

Works in VS Code Copilot, Cursor, Claude Code, Antigravity, and Gemini CLI.

> Claude Desktop users: The simplest path is Settings → Connectors → Add custom connector (Name: `extend-sdk`, URL: your MCP URL) — no AI installer needed. See Claude Desktop below.

>

> If you want to use the Quick Install prompt above, switch to the Code tab first (Chat and Cowork can't edit your config file).

>

Prefer to do it yourself? See Manual Install below.

Manual Install

Step 1: Choose your language and get your URL

The MCP URL is the hosted server's base URL followed by `/extend-mcp/{language}`:

https:///extend-mcp/{language}

• `` is the host of your organization's deployment — ask your AccelByte administrator if you're not sure.
• One hosted instance serves every language. To switch language later, just change the trailing path segment (e.g. `/extend-mcp/python` → `/extend-mcp/go`). Requesting an unknown language returns HTTP `400`.
• The base path (`/extend-mcp`) with no language serves the server's configured default language.

> No hosted instance? You can run the server yourself with Docker — see Running Locally & Self-Hosting.

Step 2: Configure your client

The server uses Streamable HTTP transport. Clients that support HTTP transport connect to the URL directly. Clients that only support stdio transport use `mcp-remote` as a bridge.

> Need `mcp-remote`? It runs via `npx`, so you need Node.js 18+ with `npx` available — verify with `npx --version`. No global install required.

Substitute your URL from Step 1 wherever you see `` below.

Visual Studio Code (Copilot)

`.vscode/mcp.json` in your workspace (or user `settings.json`):

{
  "servers": {
    "extend-sdk": {
      "type": "http",
      "url": ""
    }
  }
}

If your client can't reach an HTTP server, swap to: `{ "command": "npx", "args": ["-y", "mcp-remote", ""] }`.

See the VS Code MCP documentation.

Cursor

`.cursor/mcp.json` in your workspace (or user settings):

{
  "mcpServers": {
    "extend-sdk": {
      "type": "http",
      "url": ""
    }
  }
}

If your client can't reach an HTTP server, swap to: `{ "command": "npx", "args": ["-y", "mcp-remote", ""] }`.

See the Cursor MCP documentation.

Claude Code

claude mcp add --transport http extend-sdk

Fallback (stdio-only environments): `claude mcp add extend-sdk -- npx -y mcp-remote `.

See the Claude Code MCP documentation.

Antigravity

`mcp_config.json` in your project root:

{
  "mcpServers": {
    "extend-sdk": {
      "type": "http",
      "url": ""
    }
  }
}

If your client can't reach an HTTP server, swap to: `{ "command": "npx", "args": ["-y", "mcp-remote", ""] }`.

See the Antigravity MCP documentation.

Gemini CLI

gemini mcp add --transport http extend-sdk

Fallback (stdio-only environments): `gemini mcp add extend-sdk -- npx -y mcp-remote `.

See the Gemini CLI MCP documentation.

Claude Desktop

Option A — Custom Connector (recommended)

1. Open Settings → Connectors → Add custom connector (under the "Customize" area).

2. Fill in Name: `extend-sdk` and Remote MCP server URL: your `` from Step 1.

3. Save.

> Don't see "Add custom connector"? Some Team and Enterprise plans disable custom connectors via workspace policy. If the option is missing or greyed out, use Option B.

Option B — `mcp-remote` config file (fallback)

Edit `claude_desktop_config.json`:

• macOS: `~/Library/Application Support/Claude/claude_desktop_config.json`
• Windows: `%APPDATA%\Claude\claude_desktop_config.json`

{
  "mcpServers": {
    "extend-sdk": {
      "command": "npx",
      "args": ["-y", "mcp-remote", ""]
    }
  }
}

Restart Claude Desktop after saving.

Using the Tools

Once connected, your assistant has access to these tools. In your assistant's chat, try the example prompts below — give permission to run the tools when requested.

`search-symbols`

Search Extend SDK symbols by name, tags, or description, with fuzzy matching. Returns a paginated list of summaries.

> *"Search for symbols related to user"* · *"Find symbols for inventory"*

`describe-symbols`

Get full details for specific symbols by ID — fields, parameters, imports, example usage, return type, and required permissions.

> *"Describe the `AdminCreateUser@iam` and `User@iam` symbols"*

`create-extend-app`

A prompt template that clones an Extend app template repository and opens it (in a Dev Container when available) so you can start from a working sample.

> Invoke the `create-extend-app` prompt and follow the scenario / template / language completions.

> [!TIP]

> When coding with this MCP server, start from an Extend SDK getting-started sample or an Extend app template instead of a blank project, and add relevant source files as context for better results.

Running it yourself

Prefer to run the server locally (stdio) or host the HTTP server yourself? See **Running Locally & Self-Hosting** for Docker usage, environment variables, HTTP endpoints, smoke tests, developing from source, and releasing the image.

Troubleshooting

Tool calls fail / the server returns `400`

Check the language in your URL path. It must be one of `csharp`, `go`, `java`, or `python` (e.g. `/extend-mcp/go`). An unknown language returns HTTP `400`.

Client can't connect to the HTTP URL

Some clients only support stdio transport. Switch that client to the `mcp-remote` bridge config shown in Step 2. It needs Node.js 18+ with `npx` available (`npx --version`).

"Connection refused" or the host is unreachable

Confirm the `` and full URL are correct (ask your AccelByte administrator), and that your network can reach it.

Documentation

• Installation Guide — followed by the Quick Install prompt; readable on its own
• Running Locally & Self-Hosting — Docker, environment variables, HTTP endpoints, development, and releasing the image
• Postman Collection — import and Newman smoke-test instructions for `search-symbols` and `describe-symbols`

Contributions

This repository is published as-is. For bug reports and questions, please open an issue.