MCI Toolsets

Toolsets are collections of tools organized into reusable, shareable files. They provide a way to structure tools by domain, share them across projects, and apply filtering to control which tools are loaded in main mci.json file.

What are Toolsets?

A toolset is a separate MCI schema file that contains a collection of related tools. Unlike main entry files, toolsets:

Are stored in a library directory (default: ./mci)
Contain only tool definitions (no top-level configuration)
Can be shared across multiple projects
Support schema-level filtering when loaded

Toolsets vs Main Schema Files

Main Entry File (mci.json)

{
  "schemaVersion": "1.0",
  "metadata": {
    "name": "My Application"
  },
  "libraryDir": "./mci",
  "directoryAllowList": ["/data"],
  "enableAnyPaths": false,
  "toolsets": [{ "name": "weather" }, { "name": "database" }],
  "tools": [
    {
      "name": "main_tool",
      "execution": {
        "type": "text",
        "text": "Main tool output"
      }
    }
  ]
}

Can contain:

schemaVersion (required)
metadata (optional)
tools (optional)
toolsets (optional)
mcp_servers (optional)
libraryDir (optional)
directoryAllowList (optional)
enableAnyPaths (optional)

Toolset File (./mci/weather.mci.json)

{
  "schemaVersion": "1.0",
  "metadata": {
    "name": "Weather Toolset",
    "description": "Tools for weather information",
    "version": "1.0.0"
  },
  "tools": [
    {
      "name": "get_weather",
      "description": "Get current weather",
      "tags": ["weather", "read"],
      "execution": {
        "type": "http",
        "method": "GET",
        "url": "https://api.weather.com/current",
        "params": {
          "location": "{{props.location}}"
        }
      }
    },
    {
      "name": "get_forecast",
      "description": "Get weather forecast",
      "tags": ["weather", "read"],
      "execution": {
        "type": "http",
        "method": "GET",
        "url": "https://api.weather.com/forecast",
        "params": {
          "location": "{{props.location}}"
        }
      }
    }
  ]
}

Can contain:

schemaVersion (required)
metadata (optional - for documentation only)
tools (required)

Cannot contain:

toolsets
mcp_servers
libraryDir
directoryAllowList
enableAnyPaths

Key Differences:

Feature	Main Entry File	Toolset File
Location	Project root	`./mci` directory
Purpose	Configure application	Define tool collection
Can Define tools	✓ Yes	✗ Yes
Can reference toolsets	✓ Yes	✗ No
Can register MCP servers	✓ Yes	✗ No
Can set security configs	✓ Yes	✗ No
”tools” required	✗ No	✓ Yes

Creating Toolsets

Basic Toolset

Create a file in your toolsets directory: ./mci/github.mci.json:

{
  "schemaVersion": "1.0",
  "metadata": {
    "name": "GitHub Tools",
    "description": "Tools for GitHub API integration",
    "version": "1.0.0",
    "authors": ["DevOps Team"]
  },
  "tools": [
    {
      "name": "create_issue",
      "description": "Create a GitHub issue",
      "tags": ["github", "write"],
      "inputSchema": {
        "type": "object",
        "properties": {
          "title": { "type": "string" },
          "body": { "type": "string" },
          "repo": { "type": "string" }
        },
        "required": ["title", "repo"]
      },
      "execution": {
        "type": "http",
        "method": "POST",
        "url": "https://api.github.com/repos/{{props.repo}}/issues",
        "auth": {
          "type": "bearer",
          "token": "{{env.GITHUB_TOKEN}}"
        },
        "headers": {
          "Accept": "application/vnd.github+json"
        },
        "body": {
          "type": "json",
          "content": {
            "title": "{{props.title}}",
            "body": "{{props.body}}"
          }
        }
      }
    },
    {
      "name": "list_repos",
      "description": "List user repositories",
      "tags": ["github", "read"],
      "execution": {
        "type": "http",
        "method": "GET",
        "url": "https://api.github.com/user/repos",
        "auth": {
          "type": "bearer",
          "token": "{{env.GITHUB_TOKEN}}"
        }
      }
    }
  ]
}

Domain-Organized Toolsets

Organize toolsets by domain or purpose: ./mci/database.mci.json:

{
  "schemaVersion": "1.0",
  "metadata": {
    "name": "Database Tools"
  },
  "tools": [
    {
      "name": "query_users",
      "tags": ["database", "read"],
      // ...
      "execution": {
        "type": "cli",
        "command": "psql",
        "args": ["-c", "SELECT * FROM users;"]
      }
    },
    {
      "name": "backup_database",
      "tags": ["database", "write", "admin"],
      // ...
      "execution": {
        "type": "cli",
        "command": "pg_dump",
        "args": ["-f", "{{props.backup_file}}"]
      }
    }
  ]
}

Loading Toolsets

Toolsets are loaded in the main schema file using the toolsets field.

Basic Loading

{
  "schemaVersion": "1.0",
  "toolsets": ["weather", "github", { "name": "database" }]
}

With Custom Library Directory

{
  "schemaVersion": "1.0",
  "libraryDir": "./toolsets",
  "toolsets": ["weather"]
}

Toolset Resolving

MCI resolves toolset names using a flexible system that supports both files and directories.

Resolution Order

When you reference a toolset by name (e.g., "weather"), MCI looks for it in this order:

Directory: {libraryDir}/weather/ - If found, loads all .mci.json files in the directory
Direct File: {libraryDir}/weather
With Extension: {libraryDir}/weather.mci.json
YAML Files: Also checks .mci.yaml and .mci.yml, when extension not specified

File-Based Toolset

mci/
└── weather.mci.json

Reference:

{ "toolsets": [{ "name": "weather" }] }

Resolves to: ./mci/weather.mci.json

Directory-Based Toolset

mci/
└── github/
    ├── issues.mci.json
    ├── prs.mci.json
    └── repos.mci.json

You can Reference:

{ "toolsets": [{ "name": "github" }] }

Resolves to: All .mci.json files in ./mci/github/ And in some main files, reference only issues:

{ "toolsets": [{ "name": "github/issues.mci.json" }] }

Nested Directories

mci/
└── apis/
    ├── github/
    │   ├── issues.mci.json
    │   └── prs.mci.json
    └── weather.mci.json

Reference:

{
  "toolsets": [{ "name": "apis/github" }, { "name": "apis/weather" }]
}

Multiple Files in Directory

When loading from a directory, all .mci.json files are loaded: ./mci/monitoring/status.mci.json:

{
  "schemaVersion": "1.0",
  "tools": [
    {"name": "check_health", "execution": {...}}
  ]
}

./mci/monitoring/metrics.mci.json:

{
  "schemaVersion": "1.0",
  "tools": [
    {"name": "get_metrics", "execution": {...}}
  ]
}

Loading:

{ "toolsets": [{ "name": "monitoring" }] }

Result: Both check_health and get_metrics tools are loaded. Important Notes:

Only tools are merged from directory toolsets
Metadata is NOT merged (used for documentation only)
All files must use the same schemaVersion
Schema version mismatch will raise an error

Schema-Level Filtering

Apply filters when loading toolsets to control which tools are registered.

Filter Types

Filter Type	Description	Example
`only`	Include only specified tool names	`"get_weather, get_forecast"`
`except`	Exclude specified tool names	`"delete_user, drop_table"`
`tags`	Include only tools with matching tags	`"read, search"`
`withoutTags`	Exclude tools with matching tags	`"write, delete"`

Examples

Include Only Specific Tools:

{
  "toolsets": [
    {
      "name": "weather",
      "filter": "only",
      "filterValue": "get_weather, get_forecast"
    }
  ]
}

Result: Only get_weather and get_forecast tools are loaded from the weather toolset. Exclude Dangerous Tools:

{
  "toolsets": [
    {
      "name": "database",
      "filter": "except",
      "filterValue": "drop_table, delete_all, truncate_table"
    }
  ]
}

Result: All database tools except the excluded ones are loaded. Filter by Tags (Include):

{
  "toolsets": [
    {
      "name": "github",
      "filter": "tags",
      "filterValue": "read, search"
    }
  ]
}

Result: Only tools tagged with "read" or "search" are loaded. Filter by Tags (Exclude):

{
  "toolsets": [
    {
      "name": "github",
      "filter": "withoutTags",
      "filterValue": "write, delete, admin"
    }
  ]
}

Result: All tools except those tagged with "write", "delete", or "admin" are loaded.

Combining Multiple Toolsets with Different Filters

{
  "schemaVersion": "1.0",
  "toolsets": [
    {
      "name": "weather",
      "filter": "only",
      "filterValue": "get_weather"
    },
    {
      "name": "github",
      "filter": "withoutTags",
      "filterValue": "admin"
    },
    {
      "name": "database",
      "filter": "tags",
      "filterValue": "read"
    },
    {
      "name": "utilities"
    }
  ]
}

Toolsets are designed to be shared across projects and teams. Project Structure:

organization/
├── shared-toolsets/
│   ├── github.mci.json
│   ├── slack.mci.json
│   └── monitoring.mci.json
├── project-a/
│   ├── mci.json
│   └── mci/ -> ../shared-toolsets/
└── project-b/
    ├── mci.json
    └── mci/ -> ../shared-toolsets/

Using Symlinks:

# In project-a
ln -s ../shared-toolsets ./mci

# In project-b
ln -s ../shared-toolsets ./mci

# Add shared toolsets as submodule
git submodule add https://github.com/org/mci-toolsets.git ./mci

# Update toolsets
git submodule update --remote

npm Example:

# Publish toolsets as npm package
npm publish @company/mci-toolsets

# Install in project
npm install @company/mci-toolsets

In your schema:

{
  "libraryDir": "./node_modules/@company/mci-toolsets",
  "toolsets": [{ "name": "github" }, { "name": "slack" }]
}

Best Practices

1. Organize by Domain

mci/
├── apis/
│   ├── github.mci.json
│   ├── slack.mci.json
│   └── weather.mci.json
├── databases/
│   ├── postgres.mci.json
│   └── redis.mci.json
└── utilities/
    ├── logging.mci.json
    └── monitoring.mci.json

2. Use Tags for Categorization

{
  "tools": [
    {
      "name": "read_data",
      // ...
      "tags": ["database", "read", "safe"]
    },
    {
      "name": "delete_data",
      // ...
      "tags": ["database", "write", "destructive"]
    }
  ]
}

Then filter by tags:

{
  "toolsets": [
    {
      "name": "database",
      "filter": "tags",
      "filterValue": "read, safe"
    }
  ]
}

3. Document Toolsets

{
  "metadata": {
    "name": "GitHub API Tools",
    "description": "Complete GitHub API integration toolset. Requires GITHUB_TOKEN environment variable.",
    "version": "2.1.0",
    "authors": ["DevOps Team", "Platform Team"],
    "license": "MIT"
  }
}

4. Version Toolsets

Use semantic versioning in metadata:

{
  "metadata": {
    "version": "2.1.0"
  }
}

5. Keep Toolsets Focused

Each toolset should focus on a single domain: ✓ Good:

github.mci.json - GitHub API tools
slack.mci.json - Slack API tools
monitoring.mci.json - Monitoring tools

✗ Avoid:

misc.mci.json - Mixed unrelated tools
everything.mci.json - Too broad

Summary

Toolsets organize tools into reusable collections
Main Schema Files configure applications and reference toolsets
Toolset Files contain only tool definitions
Resolving supports both files and directories
Filtering controls which tools are loaded from toolsets
Sharing enables reuse across projects and teams

Toolsets make it easy to organize, maintain, and share tools across your organization.

Getting Started

Core Concepts

Learn more

Toolsets

MCI Toolsets

What are Toolsets?

Toolsets vs Main Schema Files

Main Entry File (mci.json)

Toolset File (./mci/weather.mci.json)

Creating Toolsets

Basic Toolset

Domain-Organized Toolsets

Loading Toolsets

Basic Loading

With Custom Library Directory

Toolset Resolving

Resolution Order

File-Based Toolset

Directory-Based Toolset

Nested Directories

Multiple Files in Directory

Schema-Level Filtering

Filter Types

Examples

Combining Multiple Toolsets with Different Filters

Best Practices

1. Organize by Domain

2. Use Tags for Categorization

3. Document Toolsets

4. Version Toolsets

5. Keep Toolsets Focused

Summary

​MCI Toolsets

​What are Toolsets?

​Toolsets vs Main Schema Files

​Main Entry File (mci.json)

​Toolset File (./mci/weather.mci.json)

​Creating Toolsets

​Basic Toolset

​Domain-Organized Toolsets

​Loading Toolsets

​Basic Loading

​With Custom Library Directory

​Toolset Resolving

​Resolution Order

​File-Based Toolset

​Directory-Based Toolset

​Nested Directories

​Multiple Files in Directory

​Schema-Level Filtering

​Filter Types

​Examples

​Combining Multiple Toolsets with Different Filters

​Sharing Toolsets

​Sharing Within Organization

​Sharing via Git Submodules

​Sharing via Package Manager

​Best Practices

​1. Organize by Domain

​2. Use Tags for Categorization

​3. Document Toolsets

​4. Version Toolsets

​5. Keep Toolsets Focused

​Summary

MCI Toolsets

What are Toolsets?

Toolsets vs Main Schema Files

Main Entry File (mci.json)

Toolset File (./mci/weather.mci.json)

Creating Toolsets

Basic Toolset

Domain-Organized Toolsets

Loading Toolsets

Basic Loading

With Custom Library Directory

Toolset Resolving

Resolution Order

File-Based Toolset

Directory-Based Toolset

Nested Directories

Multiple Files in Directory

Schema-Level Filtering

Filter Types

Examples

Combining Multiple Toolsets with Different Filters

Sharing Toolsets

Sharing Within Organization

Sharing via Git Submodules

Sharing via Package Manager

Best Practices

1. Organize by Domain

2. Use Tags for Categorization

3. Document Toolsets

4. Version Toolsets

5. Keep Toolsets Focused

Summary