Agent Plugin¶

ARC-1 is available as an Agent Plugins 1.0 package alongside the Claude Desktop .mcpb extension. One installation provides the ARC-1 MCP server and all bundled SAP development skills in this repository.

The portable package is the repository root:

arc-1/
├── plugin.json       # Agent Plugins 1.0 identity and metadata
├── mcp.json          # portable stdio MCP server definition
└── skills/           # Agent Skills discovered on demand

Compatible clients include GitHub Copilot in VS Code, Copilot CLI and the Copilot app, Cursor, ChatGPT/Codex, and other clients listed by the Agent Plugins project. Component support varies by client; ARC-1 uses the two portable 1.0 components, Agent Skills and stdio MCP.

Choose The Package For Your Client¶

Package	Best fit	Configuration experience
Agent Plugin	Copilot, VS Code, Cursor, Codex, and other Agent Plugins clients	Server + skills; put ARC-1 configuration in the client-managed plugin data directory
Claude Code plugin	Claude Code	Server + skills; Claude prompts for settings and stores the password in the OS keychain
Claude Desktop `.mcpb`	Claude Desktop	Bundled server; Desktop shows a configuration form

The Agent Plugin is a directory/repository format, not another .mcpb-style archive. Installation and marketplace distribution are managed by each compatible client.

Install¶

Local stdio use requires Node.js 22.19 or newer with npx on the executable path. The MCP entry uses arc-1@latest explicitly so an obsolete globally installed arc-1 command cannot shadow the current npm release.

GitHub Copilot CLI¶

ARC-1's repository is also a single-plugin marketplace:

copilot plugin marketplace add arc-mcp/arc-1
copilot plugin install arc-1@arc-1
copilot plugin list

The same installed plugin is discovered by current VS Code releases. In VS Code, you can instead run Chat: Install Plugin From Source and enter:

https://github.com/arc-mcp/arc-1

In Cursor, install the repository as an Agent Plugin from Customize, a team marketplace, or the documented local plugin directory.

Test A Checkout Locally¶

Use a local checkout to validate a branch before installing a published version. Neither setup stores SAP credentials in the checkout.

VS Code¶

Add the checkout to user or workspace settings, then run Developer: Reload Window:

{
  "chat.plugins.enabled": true,
  "chat.pluginLocations": {
    "/absolute/path/to/arc-1": true
  }
}

Open Chat: Open Customizations → Plugins and MCP: List Servers. Verify that:

ARC-1 appears as an Agent Plugin with the version from root plugin.json.
The plugin contributes every bundled skill and one MCP server named arc-1.
The server source is the plugin and its launch is npx -y arc-1@latest.

Cursor¶

Register the checkout in Cursor's documented local-plugin directory, then restart Cursor or run Developer: Reload Window:

mkdir -p ~/.cursor/plugins/local
ln -s /absolute/path/to/arc-1 ~/.cursor/plugins/local/arc-1

Do not replace an existing ~/.cursor/plugins/local/arc-1 path without inspecting it first. Open Customize → Plugins, Skills, and MCP Servers and verify the same version, all bundled skills, and arc-1 server.

What To Expect¶

The MCP server can complete its handshake without a .env; at that stage ARC-1 exposes only the tools allowed by its safe defaults. Missing-SAP-configuration messages are expected until ${PLUGIN_DATA}/.env is configured. This separates three failure classes:

If ARC-1 is absent from Plugins, check the local path, root plugin.json, plugin enablement, and whether the window was reloaded.
If skills appear but the MCP server does not, check that Node.js and npx are on the IDE's executable path, then inspect the MCP output for schema or process-launch errors.
If the MCP server is running but SAP calls fail, plugin loading succeeded; troubleshoot the ${PLUGIN_DATA}/.env, network/TLS, authentication, and SAP authorization separately.

Temporarily disable any manually configured ARC-1 MCP server while testing. An existing server with the same ID can shadow the plugin server, while a differently named server can expose duplicate ARC-1 tools and make the test result ambiguous. The first arc-1@latest startup may also take a few seconds while npm resolves the package.

After testing, remove the chat.pluginLocations entry and local Cursor symlink if they are no longer needed:

unlink ~/.cursor/plugins/local/arc-1

Configure The Portable MCP Server¶

Agent Plugins 1.0 does not define a portable password prompt, OAuth declaration, or credential reference. ARC-1 therefore keeps credentials out of mcp.json and starts the server with the client-provided ${PLUGIN_DATA} directory as its working directory. That directory persists across plugin updates, and ARC-1 loads its .env file on startup.

Find the installed plugin's persistent data directory. With Copilot CLI:

copilot mcp get arc-1 --json --show-secrets

Read env.PLUGIN_DATA from the result. (cwd retains the portable ${PLUGIN_DATA} token in Copilot's diagnostic output.) VS Code automatically discovers the same Copilot CLI installation. For a separate VS Code or Cursor installation, use that client's MCP diagnostics to locate the PLUGIN_DATA directory supplied to the ARC-1 process.

Create <PLUGIN_DATA>/.env with the connection and safety policy for this installation:

SAP_URL=https://your-sap-host:44300
SAP_USER=YOUR_USER
SAP_PASSWORD=YOUR_PASSWORD
SAP_CLIENT=100
SAP_LANGUAGE=EN
SAP_INSECURE=false

# Mutations and sensitive reads remain off unless explicitly enabled.
SAP_ALLOW_WRITES=false
SAP_ALLOW_DATA_PREVIEW=false
SAP_ALLOW_FREE_SQL=false

Restrict the file to your account where the operating system supports it, then restart or toggle the plugin's MCP server:

chmod 600 <PLUGIN_DATA>/.env

Do not put credentials in plugin.json, mcp.json, a committed workspace file, or the installed plugin root. The root may be replaced during an update; ${PLUGIN_DATA} is the standardized writable, persistent location. See Configuration for SSO cookies, BTP service keys, feature gates, and the complete safety surface.

Hosted or cloud-agent ARC-1

If your client should use a centrally hosted ARC-1 endpoint, disable or override the plugin's local arc-1 server with the client's native MCP configuration and keep using the bundled skills. For Copilot cloud agent, configure the remote or repository-level MCP connection with GitHub Agents secrets/variables and ensure the runner can reach SAP; a local laptop .env cannot travel to the cloud agent.

Verify¶

For Copilot CLI, these commands should show versioned plugin metadata, all bundled skills, and one local arc-1 MCP server:

copilot plugin list
copilot mcp list
copilot mcp get arc-1

ARC-1 is read-only by default. A successful install does not grant SAP permissions and does not enable writes, table-data preview, free SQL, transport mutations, or Git mutations. Those remain controlled by ARC-1's server-side settings and the connected SAP user's authorizations.

Updating And Removing¶

copilot plugin update arc-1
copilot plugin uninstall arc-1

Clients preserve ${PLUGIN_DATA} across updates and may remove it on uninstall. Back up the local .env before uninstalling if you intend to reinstall with the same settings.