The Model Context Protocol (MCP) extends Bob's capabilities by connecting to external tools and services. This guide shows you how to configure, manage, and use MCP servers with Bob.

For conceptual information, see Understanding MCP.

Configuration levels

You can configure MCP servers at two levels:

Global: Stored in ~/.bob/mcp_settings.json, applies across all workspaces
Project: Stored in .bob/mcp.json in your project root, allows team sharing via version control

Project-level configurations take precedence over global settings when server names conflict.

Edit configuration files

You can edit MCP configuration files from the settings menu:

Click the icon in the Bob panel.
Select the MCP tab.
Click the appropriate button:
- Edit Global MCP: Opens the global mcp_settings.json file
- Edit Project MCP: Opens the project-specific .bob/mcp.json file (Bob creates it if it does not exist)

Both files use JSON format with an mcpServers object containing named server configurations.

Find and install servers

IBM Bob does not include pre-installed MCP servers. To find servers:

Build your own: Use the MCP SDK to create custom servers (see the MCP GitHub repository)
Community servers: Explore community-contributed MCP servers in the MCP ecosystem

When you disable MCP servers, Bob removes all MCP-related logic and definitions from your system prompt, reducing token usage. Bob cannot connect to any MCP servers, and the use_mcp_tool and access_mcp_resource tools are unavailable. This setting is enabled by default.

To enable or disable MCP servers:

Click the icon in the Bob panel.
Select the MCP tab.
Check or uncheck Use MCP Servers.

Enable or disable MCP server creation

When you disable MCP server creation, Bob removes the instructions from your system prompt that Bob uses to write MCP servers. Bob retains the context for operating existing MCP servers, reducing token usage. This setting is enabled by default.

To enable or disable MCP server creation:

Click the icon in the Bob panel.
Select the MCP tab.
Check or uncheck Enable MCP Server Creation.

Enable or disable individual MCP tools

You can enable or disable specific tools within an MCP server to control which capabilities Bob can access. This provides fine-grained control over MCP functionality and helps reduce context window usage by excluding unused tool definitions.

To manage individual tools:

Click the icon in the Bob panel.
Select the MCP tab.
Locate the MCP server in the list.
Expand the server to view its available tools.
Toggle individual tools on or off as needed.

Disabling unused tools reduces the amount of context consumed by tool definitions, allowing more space for your code and conversation history.

Transport types

MCP supports different transport types for server communication. Choose the transport based on where your server runs and how you want to deploy it. For detailed information on all transport types, see MCP server transports.

STDIO transport

Use STDIO transport for local servers running on your machine.

Benefits:

Lower latency (no network overhead)
Better security (no network exposure)
Simpler setup (no HTTP server needed)

Configuration parameters:

Parameter	Required	Description
`command`	Yes	Executable to run (e.g., `node`, `python`, `npx`)
`args`	No	Array of arguments to pass to the command
`cwd`	No	Working directory for the server process
`env`	No	Environment variables for the server process
`alwaysAllow`	No	Array of tool names to auto-approve
`disabled`	No	Set to `true` to disable this server

Example:

{
  "mcpServers": {
    "local-server": {
      "command": "node",
      "args": ["server.js"],
      "cwd": "/path/to/project/root",
      "env": {
        "API_KEY": "your_api_key"
      },
      "alwaysAllow": ["tool1", "tool2"],
      "disabled": false
    }
  }
}

For more detailed information, see STDIO transport.

SSE transport (legacy)

Use SSE transport for remote servers accessed over HTTP/HTTPS. For new remote servers, use Streamable HTTP transport instead.

Benefits:

Can be hosted on different machines
Supports multiple client connections
Allows centralized deployment

Configuration parameters:

Parameter	Required	Description
`url`	Yes	Full URL endpoint of the remote MCP server
`headers`	No	Custom HTTP headers (e.g., authentication tokens)
`alwaysAllow`	No	Array of tool names to auto-approve
`disabled`	No	Set to `true` to disable this server

Example:

{
  "mcpServers": {
    "remote-server": {
      "url": "https://your-server-url.com/mcp",
      "headers": {
        "Authorization": "Bearer your-token"
      },
      "alwaysAllow": ["tool3"],
      "disabled": false
    }
  }
}

Create an MCP server with Bob

You can ask Bob to build custom MCP servers for specific capabilities you need.

Prerequisite: Enable the Enable MCP Server Creation setting.

To create a server:

Request the tool or capability from Bob. For example:
- "Create an MCP tool that gets the current Bitcoin price"
- "Build an MCP server to interact with the GitHub Gist API"
Bob will:
- Scaffold a server project (typically TypeScript) in the default MCP directory
- Implement the requested tool with necessary API calls
- Prompt you for API keys or credentials if needed
- Add the server configuration to your settings file
- Connect to the new server automatically

For more information about tool mechanics, see Understand Bob's tools.

Manage individual servers

To access server settings:

Click the icon in the Bob panel.
Select the MCP tab.
Locate the server in the list.

Available actions:

Delete: Click and confirm deletion
Restart: Click to restart the server
Enable/Disable: Toggle the server on or off using the power toggle
Network timeout: Set response timeout (30 seconds to 5 minutes, default 1 minute)
Manage tools: Expand the server to enable or disable individual tools

Auto-approve tools

MCP tool auto-approval is disabled by default and works per-tool:

Enable the global "Use MCP servers" option in Auto-approving actions.
In the MCP server settings, locate the tool.
Check Always allow next to the tool name.

The global setting takes precedence—if disabled, no MCP tools auto-approve.

Use MCP tools effectively

After configuring an MCP server, Bob automatically detects available tools. Effective usage depends on clear tool definitions.

Workflow

Type your request in the Bob chat interface
Bob analyzes your request and available MCP tools
Bob proposes tool use; you approve (unless auto-approved)

Write effective tool descriptions

Bob's ability to select and use tools correctly depends on description quality. Follow these guidelines when defining MCP tools:

Tool names

Use descriptive, unambiguous names that indicate the primary function.

Tool descriptions

Provide comprehensive summaries that include:

What the tool does
Its purpose and use cases
Prerequisites or important context
Expected outcomes

Parameter descriptions

For each parameter, specify:

Purpose and expected data type
Formatting requirements or constraints
Example valid values
Whether optional or required

Example

Poor description:

Gets data

Good description:

Retrieves user profile data from the API using a user ID. 
Returns JSON containing username, email, and account creation date. 
Requires valid authentication token in environment.

May send your data to external providers or third-party services
Could expose sensitive code, credentials, or proprietary information
May store or log data in ways you don't control

Recommendations:

Review the MCP server's data handling policies before use
Avoid using external MCP servers with sensitive or proprietary code
Prefer local MCP servers for confidential projects

Local security risks

Local MCP servers:

Run with the same permissions as Bob
Can access your file system, environment variables, and system resources
May execute arbitrary code on your machine
Could potentially modify or delete files

Recommendations:

Only install MCP servers from trusted sources
Review the source code of MCP servers before installation when possible
Understand what permissions and capabilities each server requires
Be cautious with servers that request broad file system access

Organizational compliance

Business and enterprise considerations:

Ensure MCP server usage aligns with your organization's security policies
Verify that data handling complies with regulatory requirements (GDPR, HIPAA, etc.)
Check if MCP servers are approved for use within restricted networks
Document which MCP servers are authorized for use in your environment

Best practices:

Maintain an inventory of approved MCP servers
Establish a review process for new MCP servers
Regularly audit MCP server usage and permissions
Provide security training for team members using MCP

Vetting MCP servers

Before installing any MCP server:

Research the source: Verify the publisher's reputation and track record
Review documentation: Understand what the server does and what it accesses
Check permissions: Evaluate what system resources the server requires
Read the code: If open source, review the implementation for security issues
Test in isolation: Try the server in a non-production environment first
Monitor behavior: Watch for unexpected network activity or file access

When in doubt, consult your security team or IT department before installing MCP servers, especially in corporate or regulated environments.

Using MCP in Bob