Feature: Add configuration options to disable project switching and cross-project operations

[bm-claudeai]

Feature Request: Project Isolation Controls

Problem Statement

Currently, Basic Memory allows unrestricted access to project switching and cross-project operations via MCP tools. This creates security concerns when using projects as isolation boundaries for different AI agents or use cases, as memories could potentially leak between projects.

Current Cross-Project Capabilities:

• Project management tools: list_memory_projects(), switch_project(), create_memory_project(), etc.
• Content tools with optional project parameters for cross-project access
• No access controls or restrictions on project discovery/switching

Use Case

Users want to:

• Use different projects for different AI agents/contexts
• Prevent memory leakage between isolated workflows
• Maintain strict security boundaries between projects
• Avoid accidental cross-project contamination

As noted by @wreed4 in #110:

"Using a project as a security boundary would be a very useful capability. Plus, if the agent can change projects, but it's previously read information from project 1 into its context, there seems like there'd be a pretty high likelihood for it to 'leak' memories into project 2."

Proposed Solution

Add granular configuration options to BasicMemoryConfig to control project isolation:

# Project security settings
disable_project_switching: bool = Field(
    default=False,
    description="Disable tools that allow switching between projects"
)
disable_cross_project_operations: bool = Field(
    default=False, 
    description="Disable project parameter in content tools"
)
restrict_project_discovery: bool = Field(
    default=False,
    description="Prevent listing all available projects"
)

Implementation Details

1. Project Management Tool Filtering

When disable_project_switching=True:

• Remove these tools from MCP registration:
  • list_memory_projects()
  • switch_project()
  • create_memory_project()
  • delete_project()
  • set_default_project()
• Keep only read-only project info: get_current_project()

2. Cross-Project Parameter Validation

When disable_cross_project_operations=True:

• Remove/ignore optional project parameters from content tools
• Reject operations that specify a project different from current session
• All operations work only within the currently active project

3. Project Discovery Restriction

When restrict_project_discovery=True:

• list_memory_projects() returns only current project (if enabled)
• Prevent enumeration of all available projects
• Error messages don't leak project names

Configuration Options

Option 1: MCP Server Arguments

# Disable all project switching
uvx basic-memory --no-project-switching mcp

# Disable cross-project operations
uvx basic-memory --no-cross-project mcp

# Strict isolation mode
uvx basic-memory --project-isolation mcp

Option 2: Configuration File

{
  "project_security": {
    "disable_project_switching": true,
    "disable_cross_project_operations": true,
    "restrict_project_discovery": true
  }
}

Option 3: Environment Variables

BASIC_MEMORY_DISABLE_PROJECT_SWITCHING=true
BASIC_MEMORY_DISABLE_CROSS_PROJECT=true
BASIC_MEMORY_RESTRICT_PROJECT_DISCOVERY=true

Benefits

• ✅ Security: Maintains strict isolation boundaries for multi-agent scenarios
• ✅ Data Safety: Prevents accidental cross-project contamination
• ✅ Backward Compatibility: Defaults preserve current behavior
• ✅ Granular Control: Users can choose which restrictions to apply
• ✅ Simple Implementation: Clear configuration-driven approach

Acceptance Criteria

• Add configuration options to control project isolation
• Implement tool filtering based on configuration
• Add parameter validation for cross-project operations
• Update documentation with security configuration guidance
• Add tests for restricted mode behavior
• Ensure backward compatibility (current behavior by default)
• Add CLI flags for common isolation scenarios

Priority

Medium-High - Important for users requiring security isolation between projects, enables broader adoption in multi-agent environments.

Related Issues

• Closes discussion from Add flag to disable project switching #110 (original bug was fixed in v0.13.0)
• Addresses security concerns raised by @wreed4 and @wtfzambo

Implementation Areas

• src/basic_memory/config.py - Add configuration options
• src/basic_memory/mcp/server.py - Conditional tool registration
• src/basic_memory/mcp/tools/ - Parameter validation in content tools
• src/basic_memory/cli/ - Add CLI flags for common scenarios
• Documentation updates for security configuration