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| 1 | +# GitHub Remote MCP Integration Guide for MCP Host Authors |
| 2 | + |
| 3 | +This guide outlines high-level considerations for MCP Host authors who want to allow installation of the Remote GitHub MCP server. |
| 4 | + |
| 5 | +The goal is to explain the architecture at a high-level, define key requirements, and provide guidance to get you started, while pointing to official documentation for deeper implementation details. |
| 6 | + |
| 7 | +--- |
| 8 | + |
| 9 | +## Table of Contents |
| 10 | + |
| 11 | +- [Understanding MCP Architecture](#understanding-mcp-architecture) |
| 12 | +- [Connecting to the Remote GitHub MCP Server](#connecting-to-the-remote-github-mcp-server) |
| 13 | + - [Authentication and Authorization](#authentication-and-authorization) |
| 14 | + - [OAuth Support on GitHub](#oauth-support-on-github) |
| 15 | + - [Create an OAuth-enabled App Using the GitHub UI](#create-an-oauth-enabled-app-using-the-github-ui) |
| 16 | + - [Things to Consider](#things-to-consider) |
| 17 | + - [Initiating the OAuth Flow from your Client Application](#initiating-the-oauth-flow-from-your-client-application) |
| 18 | +- [Handling Organization Access Restrictions](#handling-organization-access-restrictions) |
| 19 | +- [Essential Security Considerations](#essential-security-considerations) |
| 20 | +- [Additional Resources](#additional-resources) |
| 21 | + |
| 22 | +--- |
| 23 | + |
| 24 | +## Understanding MCP Architecture |
| 25 | + |
| 26 | +The Model Context Protocol (MCP) enables seamless communication between your application and various external tools through an architecture defined by the [MCP Standard](https://modelcontextprotocol.io/). |
| 27 | + |
| 28 | +### High-level Architecture |
| 29 | + |
| 30 | +The diagram below illustrates how a single client application can connect to multiple MCP Servers, each providing access to a unique set of resources. Notice that some MCP Servers are running locally (side-by-side with the client application) while others are hosted remotely. GitHub's MCP offerings are available to run either locally or remotely. |
| 31 | + |
| 32 | +```mermaid |
| 33 | +flowchart LR |
| 34 | + subgraph "Local Runtime Environment" |
| 35 | + subgraph "Client Application (e.g., IDE)" |
| 36 | + CLIENTAPP[Application Runtime] |
| 37 | + CX["MCP Client (FileSystem)"] |
| 38 | + CY["MCP Client (GitHub)"] |
| 39 | + CZ["MCP Client (Other)"] |
| 40 | + end |
| 41 | +
|
| 42 | + LOCALMCP[File System MCP Server] |
| 43 | + end |
| 44 | +
|
| 45 | + subgraph "Internet" |
| 46 | + GITHUBMCP[GitHub Remote MCP Server] |
| 47 | + OTHERMCP[Other Remote MCP Server] |
| 48 | + end |
| 49 | +
|
| 50 | + CLIENTAPP --> CX |
| 51 | + CLIENTAPP --> CY |
| 52 | + CLIENTAPP --> CZ |
| 53 | +
|
| 54 | + CX <-->|"stdio"| LOCALMCP |
| 55 | + CY <-->|"OAuth 2.0 + HTTP/SSE"| GITHUBMCP |
| 56 | + CZ <-->|"OAuth 2.0 + HTTP/SSE"| OTHERMCP |
| 57 | +``` |
| 58 | + |
| 59 | +### Runtime Environment |
| 60 | + |
| 61 | +- **Application**: The user-facing application you are building. It instantiates one or more MCP clients and orchestrates tool calls. |
| 62 | +- **MCP Client**: A component within your client application that maintains a 1:1 connection with a single MCP server. |
| 63 | +- **MCP Server**: A service that provides access to a specific set of tools. |
| 64 | + - **Local MCP Server**: An MCP Server running locally, side-by-side with the Application. |
| 65 | + - **Remote MCP Server**: An MCP Server running remotely, accessed via the internet. Most Remote MCP Servers require authentication via OAuth. |
| 66 | + |
| 67 | +For more detail, see the [official MCP specification](https://modelcontextprotocol.io/specification/draft). |
| 68 | + |
| 69 | +> [!NOTE] |
| 70 | +> GitHub offers both a Local MCP Server and a Remote MCP Server. |
| 71 | +
|
| 72 | +--- |
| 73 | + |
| 74 | +## Connecting to the Remote GitHub MCP Server |
| 75 | + |
| 76 | +### Authentication and Authorization |
| 77 | + |
| 78 | +GitHub MCP Servers require a valid access token in the `Authorization` header. This is true for both the Local GitHub MCP Server and the Remote GitHub MCP Server. |
| 79 | + |
| 80 | +For the Remote GitHub MCP Server, the recommended way to obtain a valid access token is to ensure your client application supports [OAuth 2.1](https://datatracker.ietf.org/doc/html/draft-ietf-oauth-v2-1-13). It should be noted, however, that you may also supply any valid access token. For example, you may supply a pre-generated Personal Access Token (PAT). |
| 81 | + |
| 82 | + |
| 83 | +> [!IMPORTANT] |
| 84 | +> The Remote GitHub MCP Server itself does not provide Authentication services. |
| 85 | +> Your client application must obtain valid GitHub access tokens through one of the supported methods. |
| 86 | +
|
| 87 | +The expected flow for obtaining a valid access token via OAuth is depicted in the [MCP Specification](https://modelcontextprotocol.io/specification/draft/basic/authorization#authorization-flow-steps). For convenience, we've embedded a copy of the authorization flow below. Please study it carefully as the remainder of this document is written with this flow in mind. |
| 88 | + |
| 89 | +```mermaid |
| 90 | +sequenceDiagram |
| 91 | + participant B as User-Agent (Browser) |
| 92 | + participant C as Client |
| 93 | + participant M as MCP Server (Resource Server) |
| 94 | + participant A as Authorization Server |
| 95 | +
|
| 96 | + C->>M: MCP request without token |
| 97 | + M->>C: HTTP 401 Unauthorized with WWW-Authenticate header |
| 98 | + Note over C: Extract resource_metadata URL from WWW-Authenticate |
| 99 | +
|
| 100 | + C->>M: Request Protected Resource Metadata |
| 101 | + M->>C: Return metadata |
| 102 | +
|
| 103 | + Note over C: Parse metadata and extract authorization server(s)<br/>Client determines AS to use |
| 104 | +
|
| 105 | + C->>A: GET /.well-known/oauth-authorization-server |
| 106 | + A->>C: Authorization server metadata response |
| 107 | +
|
| 108 | + alt Dynamic client registration |
| 109 | + C->>A: POST /register |
| 110 | + A->>C: Client Credentials |
| 111 | + end |
| 112 | +
|
| 113 | + Note over C: Generate PKCE parameters |
| 114 | + C->>B: Open browser with authorization URL + code_challenge |
| 115 | + B->>A: Authorization request |
| 116 | + Note over A: User authorizes |
| 117 | + A->>B: Redirect to callback with authorization code |
| 118 | + B->>C: Authorization code callback |
| 119 | + C->>A: Token request + code_verifier |
| 120 | + A->>C: Access token (+ refresh token) |
| 121 | + C->>M: MCP request with access token |
| 122 | + M-->>C: MCP response |
| 123 | + Note over C,M: MCP communication continues with valid token |
| 124 | +``` |
| 125 | + |
| 126 | +> [!NOTE] |
| 127 | +> Dynamic Client Registration is NOT supported by Remote GitHub MCP Server at this time. |
| 128 | +
|
| 129 | + |
| 130 | +#### OAuth Support on GitHub |
| 131 | + |
| 132 | +GitHub offers two solutions for obtaining access tokens via OAuth: [**GitHub Apps**](https://docs.github.com/en/apps/using-github-apps/about-using-github-apps#about-github-apps) and [**OAuth Apps**](https://docs.github.com/en/apps/oauth-apps). These solutions are typically created, administered, and maintained by GitHub Organization administrators. Collaborate with a GitHub Organization administrator to configure either a **GitHub App** or an **OAuth App** to allow your client application to utilize GitHub OAuth support. Furthermore, be aware that it may be necessary for users of your client application to register your **GitHub App** or **OAuth App** within their own GitHub Organization in order to generate authorization tokens capable of accessing Organization's GitHub resources. |
| 133 | + |
| 134 | +> [!TIP] |
| 135 | +> Before proceeding, check whether your organization already supports one of these solutions. Administrators of your GitHub Organization can help you determine what **GitHub Apps** or **OAuth Apps** are already registered. If there's an existing **GitHub App** or **OAuth App** that fits your use case, consider reusing it for Remote MCP Authorization. That said, be sure to take heed of the following warning. |
| 136 | +
|
| 137 | +> [!WARNING] |
| 138 | +> Both **GitHub Apps** and **OAuth Apps** require the client application to pass a "client secret" in order to initiate the OAuth flow. If your client application is designed to run in an uncontrolled environment (i.e. customer-provided hardware), end users will be able to discover your "client secret" and potentially exploit it for other purposes. In such cases, our recommendation is to register a new **GitHub App** (or **OAuth App**) exclusively dedicated to servicing OAuth requests from your client application. |
| 139 | +
|
| 140 | +#### Create an OAuth-enabled App Using the GitHub UI |
| 141 | + |
| 142 | +Detailed instructions for creating a **GitHub App** can be found at ["Creating GitHub Apps"](https://docs.github.com/en/apps/creating-github-apps/about-creating-github-apps/about-creating-github-apps#building-a-github-app). (RECOMMENDED)<br/> |
| 143 | +Detailed instructions for creating an **OAuth App** can be found ["Creating an OAuth App"](https://docs.github.com/en/apps/oauth-apps/building-oauth-apps/creating-an-oauth-app). |
| 144 | + |
| 145 | +For guidance on which type of app to choose, see ["Differences Between GitHub Apps and OAuth Apps"](https://docs.github.com/en/apps/oauth-apps/building-oauth-apps/differences-between-github-apps-and-oauth-apps). |
| 146 | + |
| 147 | +#### Things to Consider: |
| 148 | +- Tokens provided by **GitHub Apps** are generally more secure because they: |
| 149 | + - include an expiration |
| 150 | + - include support for fine-grained permissions |
| 151 | +- **GitHub Apps** must be installed on a GitHub Organization before they can be used.<br/>In general, installation must be approved by someone in the Organization with administrator permissions. For more details, see [this explanation](https://docs.github.com/en/apps/oauth-apps/building-oauth-apps/differences-between-github-apps-and-oauth-apps#who-can-install-github-apps-and-authorize-oauth-apps).<br/>By contrast, **OAuth Apps** don't require installation and, typically, can be used immediately. |
| 152 | +- Members of an Organization may use the GitHub UI to [request that a GitHub App be installed](https://docs.github.com/en/apps/using-github-apps/requesting-a-github-app-from-your-organization-owner) organization-wide. |
| 153 | +- While not strictly necessary, if you expect that a wide range of users will use your MCP Server, consider publishing its corresponding **GitHub App** or **OAuth App** on the [GitHub App Marketplace](https://github.com/marketplace?type=apps) to ensure that it's discoverable by your audience. |
| 154 | + |
| 155 | + |
| 156 | +#### Initiating the OAuth Flow from your Client Application |
| 157 | + |
| 158 | +For **GitHub Apps**, details on initiating the OAuth flow from a client application are described in detail [here](https://docs.github.com/en/apps/creating-github-apps/authenticating-with-a-github-app/generating-a-user-access-token-for-a-github-app#using-the-web-application-flow-to-generate-a-user-access-token). |
| 159 | + |
| 160 | +For **OAuth Apps**, details on initiating the OAuth flow from a client application are described in detail [here](https://docs.github.com/en/apps/oauth-apps/building-oauth-apps/authorizing-oauth-apps#web-application-flow). |
| 161 | + |
| 162 | +> [!IMPORTANT] |
| 163 | +> For endpoint discovery, be sure to honor the [`WWW-Authenticate` information provided](https://modelcontextprotocol.io/specification/draft/basic/authorization#authorization-server-location) by the Remote GitHub MCP Server rather than relying on hard-coded endpoints like `https://github.com/login/oauth/authorize`. |
| 164 | +
|
| 165 | + |
| 166 | +### Handling Organization Access Restrictions |
| 167 | +Organizations may block **GitHub Apps** and **OAuth Apps** until explicitly approved. Within your client application code, you can provide actionable next steps for a smooth user experience in the event that OAuth-related calls fail due to your **GitHub App** or **OAuth App** being unavailable (i.e. not registered within the user's organization). |
| 168 | + |
| 169 | +1. Detect the specific error. |
| 170 | +2. Notify the user clearly. |
| 171 | +3. Depending on their GitHub organization privileges: |
| 172 | + - Org Members: Prompt them to request approval from a GitHub organization admin, within the organization where access has not been approved. |
| 173 | + - Org Admins: Link them to the corresponding GitHub organization’s App approval settings at `https://github.com/organizations/[ORG_NAME]/settings/oauth_application_policy` |
| 174 | + |
| 175 | + |
| 176 | +## Essential Security Considerations |
| 177 | +- **Token Storage**: Use secure platform APIs (e.g. keytar for Node.js). |
| 178 | +- **Input Validation**: Sanitize all tool arguments. |
| 179 | +- **HTTPS Only**: Never send requests over plaintext HTTP. Always use HTTPS in production. |
| 180 | +- **PKCE:** We strongly recommend implementing [PKCE](https://datatracker.ietf.org/doc/html/rfc7636) for all OAuth flows to prevent code interception, to prepare for upcoming PKCE support. |
| 181 | + |
| 182 | +## Additional Resources |
| 183 | +- [MCP Official Spec](https://modelcontextprotocol.io/specification/draft) |
| 184 | +- [MCP SDKs](https://modelcontextprotocol.io/sdk/java/mcp-overview) |
| 185 | +- [GitHub Docs on Creating GitHub Apps](https://docs.github.com/en/apps/creating-github-apps) |
| 186 | +- [GitHub Docs on Using GitHub Apps](https://docs.github.com/en/apps/using-github-apps/about-using-github-apps) |
| 187 | +- [GitHub Docs on Creating OAuth Apps](https://docs.github.com/en/apps/oauth-apps) |
| 188 | +- GitHub Docs on Installing OAuth Apps into a [Personal Account](https://docs.github.com/en/apps/oauth-apps/using-oauth-apps/installing-an-oauth-app-in-your-personal-account) and [Organization](https://docs.github.com/en/apps/oauth-apps/using-oauth-apps/installing-an-oauth-app-in-your-organization) |
| 189 | +- [Managing OAuth Apps at the Organization Level](https://docs.github.com/en/organizations/managing-oauth-access-to-your-organizations-data) |
| 190 | +- [Managing Programmatic Access at the GitHub Organization Level](https://docs.github.com/en/organizations/managing-programmatic-access-to-your-organization) |
| 191 | +- [Building Copilot Extensions](https://docs.github.com/en/copilot/building-copilot-extensions) |
| 192 | +- [Managing App/Extension Visibility](https://docs.github.com/en/copilot/building-copilot-extensions/managing-the-availability-of-your-copilot-extension) (including GitHub Marketplace information) |
| 193 | +- [Example Implementation in VS Code Repository](https://github.com/microsoft/vscode/blob/main/src/vs/workbench/api/common/extHostMcp.ts#L313) |
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