Feature Area

Integration with external tools

Is your feature request related to a an existing bug? Please link it here.

Feature Request: HTTP Support for Local MCP Servers

Summary

Add support for http:// URLs in MCP server references to enable local MCP server connections. Currently, CrewAI only supports https:// URLs for external MCP servers, which prevents developers from using local MCP servers running on http://localhost or other local HTTP endpoints.

Use Case

When developing with CrewAI and MCP (Model Context Protocol), developers often run local MCP servers for:

• Local development and testing
• Internal tooling and services
• Development environments without SSL certificates
• Localhost-based MCP servers (e.g., http://localhost:7365/mcp)

Currently, these local servers cannot be used with CrewAI agents because the library only accepts https:// URLs.

Current Behavior

1. Validation: The validate_mcps() method in base_agent.py has inconsistent behavior:

   • It accepts http:// URLs in the validation check
   • But the error message incorrectly states only https:// is supported
   • This creates confusion and inconsistent behavior

2. Tool Retrieval: The _get_mcp_tools_from_string() method in agent/core.py only handles https:// URLs:

   if mcp_ref.startswith("https://"):
       return self._get_external_mcp_tools(mcp_ref)

   • http:// URLs are silently ignored, returning an empty tool list
   • No error is raised, making debugging difficult

Expected Behavior

• Accept http:// URLs in MCP server references alongside https://
• Successfully retrieve tools from local MCP servers using http:// URLs
• Provide clear error messages that accurately reflect supported URL schemes
• Support both http:// and https:// for external MCP server connections

Describe the solution you'd like

Proposed Solution

1. Update Validator (base_agent.py):

   • Accept http://, https://, and crewai-amp: in validation
   • Update error message to reflect all supported schemes

2. Update Tool Retrieval (agent/core.py):

   • Modify _get_mcp_tools_from_string() to handle both http:// and https://
   • Ensure _get_external_mcp_tools() works with both protocols

3. Documentation:

   • Update docstrings to mention HTTP support
   • Add examples showing local MCP server usage

Example Usage

agent = Agent(
    role="Data Collector",
    goal="Collect data using MCP tools",
    backstory="...",
    mcps=["http://localhost:7365/mcp#diff_general_info"]  # Currently fails
)

Impact

• High: This is a blocker for local development workflows
• Low Risk: HTTP support is a straightforward addition that doesn't break existing functionality
• Developer Experience: Significantly improves the development experience for MCP integration

Technical Details

The changes required are minimal:

• Update URL scheme checks from startswith("https://") to startswith(("http://", "https://"))
• Ensure the underlying MCP client library supports HTTP (most do)
• Update validation logic and error messages

Related Issues

• Local MCP servers are a common development pattern
• Many MCP server implementations default to HTTP for local development
• SSL certificates are not always available in development environments

Describe alternatives you've considered

No response

Additional context

No response

Willingness to Contribute

Yes, I'd be happy to submit a pull request