Terraform Registry MCP Server

A Model Context Protocol (MCP) server that provides tools for interacting with the Terraform Registry API. This server enables AI agents to query provider information, resource details, and module metadata.

[!IMPORTANT] This project was used as a PoC for a new official Terraform MCP server. This repo has been archived in favor of that one.

Installation

Installing in Cursor

To install and use this MCP server in Cursor:

1. In Cursor, open Settings (⌘+,) and navigate to the "MCP" tab.

2. Click "+ Add new MCP server."

3. Enter the following:

   • Name: terraform-registry
   • Type: command
   • Command: npx -y terraform-mcp-server

4. Click "Add" then scroll to the server and click "Disabled" to enable the server.

5. Restart Cursor, if needed, to ensure the MCP server is properly loaded.

Installing in Claude Desktop

To install and use this MCP server in Claude Desktop:

1. In Claude Desktop, open Settings (⌘+,) and navigate to the "Developer" tab.

2. Click "Edit Config" at the bottom of the window.

3. Edit the file (~/Library/Application Support/Claude/claude_desktop_config.json) to add the following code, then Save the file.

{
  "mcpServers": {
    "terraform-registry": {
      "command": "npx",
      "args": ["-y", "terraform-mcp-server"]
    }
  }
}

4. Restart Claude Desktop to ensure the MCP server is properly loaded.

Tools

The following tools are available in this MCP server:

Core Registry Tools

Tool	Description
providerDetails	Gets detailed information about a Terraform provider
resourceUsage	Gets example usage of a Terraform resource and related resources
moduleSearch	Searches for and recommends Terraform modules based on a query
listDataSources	Lists all available data sources for a provider and their basic details
resourceArgumentDetails	Fetches comprehensive details about a resource type's arguments
moduleDetails	Retrieves detailed metadata for a Terraform module
functionDetails	Gets details about a Terraform provider function
providerGuides	Lists and views provider-specific guides and documentation
policySearch	Searches for policy libraries in the Terraform Registry
policyDetails	Gets detailed information about a specific policy library

Terraform Cloud Tools

These tools require a Terraform Cloud API token (TFC_TOKEN):

Tool	Description
listOrganizations	Lists all organizations the authenticated user has access to
privateModuleSearch	Searches for private modules in an organization
privateModuleDetails	Gets detailed information about a private module
explorerQuery	Queries the Terraform Cloud Explorer API to analyze data
listWorkspaces	Lists workspaces in an organization
workspaceDetails	Gets detailed information about a specific workspace
lockWorkspace	Locks a workspace to prevent runs
unlockWorkspace	Unlocks a workspace to allow runs
listRuns	Lists runs for a workspace
runDetails	Gets detailed information about a specific run
createRun	Creates a new run for a workspace
applyRun	Applies a run that's been planned
cancelRun	Cancels a run that's in progress
listWorkspaceResources	Lists resources in a workspace

Resources

The MCP server supports the following resource URIs for listing and reading via the resources/* methods:

Resource Type	Example URI(s)	Description
Providers	terraform:providers	List all namespaces/providers
	terraform:provider:<namespace>/<name>	Get details for a specific provider
Provider Versions	terraform:provider:<namespace>/<name>/versions	List available versions for a provider
Provider Resources	terraform:provider:<namespace>/<name>/resources	List resources for a provider
	terraform:resource:<namespace>/<name>/<resource_name>	Get details for a specific resource type
Provider Data Sources	terraform:provider:<namespace>/<name>/dataSources	List data sources for a provider
	terraform:dataSource:<namespace>/<name>/<data_source_name>	Get details for a specific data source
Provider Functions	terraform:provider:<namespace>/<name>/functions	List functions for a provider
	terraform:function:<namespace>/<name>/<function_name>	Get details for a specific function

The server also supports resources/templates/list to provide templates for creating:

• terraform:provider
• terraform:resource
• terraform:dataSource

Prompts

The following prompts are available for generating contextual responses:

Prompt	Description	Required Arguments
migrate-clouds	Generate Terraform code to migrate infrastructure between cloud providers	sourceCloud, targetCloud, terraformCode
generate-resource-skeleton	Helps users quickly scaffold new Terraform resources with best practices	resourceType
optimize-terraform-module	Provides actionable recommendations for improving Terraform code	terraformCode
migrate-provider-version	Assists with provider version upgrades and breaking changes	providerName, currentVersion, targetVersion, terraformCode (optional)
analyze-workspace-runs	Analyzes recent run failures and provides troubleshooting guidance for Terraform Cloud workspaces	workspaceId, runsToAnalyze (optional, default: 5)

Known Issues with Prompts

Note: There is a known issue with the getPrompt functionality that can cause server crashes. The server properly registers prompts and can list them, but direct requests using the getPrompt method may cause connectivity issues. This is being investigated and may be related to SDK compatibility or implementation details. Until resolved, use listPrompts to see available prompts but avoid direct getPrompt calls.

Running the Server

The server runs using stdio transport for MCP communication:

npm install
npm start

Configuration with Environment Variables

The server can be configured using environment variables:

Environment Variable	Description	Default Value
TERRAFORM_REGISTRY_URL	Base URL for Terraform Registry API	https://registry.terraform.io
DEFAULT_PROVIDER_NAMESPACE	Default namespace for providers	hashicorp
LOG_LEVEL	Logging level (error, warn, info, debug)	info
REQUEST_TIMEOUT_MS	Timeout for API requests in milliseconds	10000
RATE_LIMIT_ENABLED	Enable rate limiting for API requests	false
RATE_LIMIT_REQUESTS	Number of requests allowed in time window	60
RATE_LIMIT_WINDOW_MS	Time window for rate limiting in milliseconds	60000
TFC_TOKEN	Terraform Cloud API token for private registry access (optional)

Example usage with environment variables:

# Set environment variables
export LOG_LEVEL="debug"
export REQUEST_TIMEOUT_MS="15000"
export TFC_TOKEN="your-terraform-cloud-token"

# Run the server
npm start

Testing

See the TESTS.md file for information about testing this project.