AWS SSO MCP

A Model Context Protocol (MCP) server for refreshing AWS SSO authentication tokens. Works with multiple MCP clients including Claude Desktop, Claude Code, Cursor, VS Code, Gemini CLI, and more.

How It Works

1. When AWS operations fail due to expired SSO tokens, Claude detects the error
2. Claude calls refresh_aws_sso_token with the appropriate profile or server name
3. The server looks up the AWS profile from MCP config files (if server is provided)
4. A browser window opens for SSO authentication
5. Once authenticated, the original operation can be retried

Supported MCP Clients

The server automatically detects AWS profile settings from the following MCP clients:

Client	Config Location
Claude Code	.mcp.json (project), ~/.mcp.json (user)
Claude Desktop	~/Library/Application Support/Claude/claude_desktop_config.json (macOS)
Cursor	.cursor/mcp.json (project), ~/.cursor/mcp.json (user)
VS Code	.vscode/mcp.json
Gemini CLI	.gemini/settings.json (project), ~/.gemini/settings.json (user)
Copilot CLI	~/.copilot/mcp-config.json
Amazon Q	~/.aws/amazonq/mcp.json
Cline	VS Code extension settings

Installation

Claude Code (Plugin)

/plugin marketplace add veelenga/aws-sso-mcp
/plugin install aws-sso-mcp@aws-sso-mcp

Restart Claude Code, then verify with /mcp.

Claude Code (Manual) - WIP

npm install -g aws-sso-mcp
claude mcp add --scope user aws-sso aws-sso-mcp

Claude Desktop

Add to your configuration file:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json

Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "aws-sso": {
      "command": "npx",
      "args": ["-y", "aws-sso-mcp"]
    }
  }
}

Tool

refresh_aws_sso_token

Initiates the AWS SSO login flow to refresh expired authentication tokens. Opens a browser window for the user to complete authentication.

Parameter	Type	Required	Description
profile	string	No*	AWS profile name to refresh token for. Takes precedence over server parameter.
server	string	No*	MCP server name to look up AWS_PROFILE from MCP config files (e.g., bedrock-kb).

*At least one of profile or server must be provided.

Profile resolution order:

1. Explicit profile parameter
2. Look up from MCP config files by server name

Example response:

{
  "success": true,
  "profile": "MCPServerReadAccess",
  "profileSource": "mcp_config",
  "message": "Successfully refreshed SSO token for profile \"MCPServerReadAccess\"."
}

Bundled Skill

The plugin includes an aws-sso-refresh skill that provides:

• Automatic detection of token expiration errors
• Best practices for handling AWS SSO authentication
• Workflow guidance for retry operations

Development

# Install dependencies
npm install

# Build
npm run build

# Run tests
npm test

# Test with MCP Inspector
npx @modelcontextprotocol/inspector node dist/index.js

Requirements

• Node.js 18+
• AWS CLI v2 installed and configured with SSO profiles
• An AWS SSO profile configured in ~/.aws/config

Security

The server implements several security measures:

• Explicit profile selection: Requires profile or server parameter to prevent unintended authentication actions
• Trusted AWS CLI paths: Only executes AWS CLI from system directories (/usr/bin, /usr/local/bin, /opt/homebrew/bin)
• Symlink validation: Resolves symlinks and verifies the real path is also in a trusted location
• Minimal environment: Spawns processes with a sanitized environment to prevent injection attacks (e.g., LD_PRELOAD)
• No secrets in responses: CLI output is not included in responses to prevent leaking device codes or URLs

License

MIT