MCP Setup

Sibyl exposes an HTTP MCP endpoint at /mcp. Most agents do not need it: an agent that can run shell commands uses the sibyl CLI, and sibyl setup signs the CLI in and installs the skill that teaches it. Use this page for clients that only speak MCP, such as Cursor or Claude Desktop, with a scoped API key that has the mcp scope.

Create The Key

sibyl auth api-key create --name "mcp-client" --scopes mcp

Use a project or memory-space restriction when the client should only see a specific workspace:

sibyl auth api-key create --name "project-agent" \
  --scopes mcp \
  --projects proj_abc123

Shared HTTP Configuration

Most MCP clients accept the same HTTP shape. A local sibyl up install lives at http://localhost:3334/mcp; on a remote or shared server, swap in your own host:

{
  "mcpServers": {
    "sibyl": {
      "type": "http",
      "url": "http://localhost:3334/mcp",
      "headers": {
        "Authorization": "Bearer sk_live_replace_me"
      }
    }
  }
}

Keep the key out of committed files. Prefer your client's secret store or a local ignored config file.

Cursor

Add Sibyl as an HTTP MCP server in Cursor's MCP settings:

{
  "mcpServers": {
    "sibyl": {
      "type": "http",
      "url": "http://localhost:3334/mcp",
      "headers": {
        "Authorization": "Bearer sk_live_replace_me"
      }
    }
  }
}

Restart the MCP server from Cursor's settings after editing the config.

Claude Code

Use Claude Code's MCP configuration with the same HTTP server entry:

{
  "mcpServers": {
    "sibyl": {
      "type": "http",
      "url": "http://localhost:3334/mcp",
      "headers": {
        "Authorization": "Bearer sk_live_replace_me"
      }
    }
  }
}

Add a short project instruction so agents actually use the memory loop:

Search Sibyl before non-trivial work, capture durable gotchas after solving them, and keep task
state current when work spans multiple steps.

Claude Desktop

Claude Desktop can use the same HTTP MCP server entry in its MCP server config:

{
  "mcpServers": {
    "sibyl": {
      "type": "http",
      "url": "http://localhost:3334/mcp",
      "headers": {
        "Authorization": "Bearer sk_live_replace_me"
      }
    }
  }
}

Restart Claude Desktop after changing the MCP config.

Verify

A connected client sees 13 Sibyl tools plus the sibyl://health and sibyl://stats resources. Ask the client to search Sibyl for a known memory. If the request fails:

• Confirm the API key starts with sk_live_ or sk_test_.
• Confirm the key has the mcp scope.
• Confirm the client can reach http://localhost:3334/mcp.
• Check Settings, Security, API Keys to make sure the key was not revoked.