Terraform MCP Server

The Terraform MCP Server is a Model Context Protocol (MCP) server that provides seamless integration with Terraform Registry APIs, enabling advanced automation and interaction capabilities for Infrastructure as Code (IaC) development.

Features

• Dual Transport Support: Both Stdio and StreamableHTTP transports with configurable endpoints
• Terraform Registry Integration: Direct integration with public Terraform Registry APIs for providers, modules, and policies
• HCP Terraform & Terraform Enterprise Support: Full workspace management, organization/project listing, and private registry access
• Workspace Operations: Create, update, delete workspaces with support for variables, tags, and run management
• OTel metrics for monitoring tool usage: Integration with open telemetry meters to track tool-call volume, latency and failures in Streamable HTTP mode. Also exposes default http server metrics when this feature is enabled

Security Note: At this stage, the MCP server is intended for local use only. If using the StreamableHTTP transport, always configure the MCP_ALLOWED_ORIGINS environment variable to restrict access to trusted origins only. This helps prevent DNS rebinding attacks and other cross-origin vulnerabilities.

Security Note: Depending on the query, the MCP server may expose certain Terraform data to the MCP client and LLM. Do not use the MCP server with untrusted MCP clients or LLMs.

Legal Note: Your use of a third party MCP Client/LLM is subject solely to the terms of use for such MCP/LLM, and IBM is not responsible for the performance of such third party tools. IBM expressly disclaims any and all warranties and liability for third party MCP Clients/LLMs, and may not be able to provide support to resolve issues which are caused by the third party tools.

Caution: The outputs and recommendations provided by the MCP server are generated dynamically and may vary based on the query, model, and the connected MCP client. Users should thoroughly review all outputs/recommendations to ensure they align with their organization’s security best practices, cost-efficiency goals, and compliance requirements before implementation.

Prerequisites

1. Ensure Docker is installed and running to use the server in a containerized environment.
2. Install an AI assistant that supports the Model Context Protocol (MCP).

Command Line Options

Environment Variables:

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# Stdio mode
terraform-mcp-server stdio [--log-file /path/to/log] [--log-level info] [--log-format text] [--toolsets <toolsets>] [--tools <tools>]

# StreamableHTTP mode
terraform-mcp-server streamable-http [--transport-port 8080] [--transport-host 127.0.0.1] [--mcp-endpoint /mcp] [--log-file /path/to/log] [--log-level info] [--log-format text] [--toolsets <toolsets>] [--tools <tools>]

Instructions

Default instructions for the MCP server is located in cmd/terraform-mcp-server/instructions.md, if those do not seem appropriate for your organization's Terraform practices or if the MCP server is producing inaccurate responses, please replace them with your own instructions and rebuild the container or binary. An example of such instruction is located in instructions/example-mcp-instructions.md

AGENTS.md essentially behaves as READMEs for coding agents: a dedicated, predictable place to provide the context and instructions to help AI coding agents work on your project. One AGENTS.md file works with different coding agents. An example of such instruction is located in instructions/example-AGENTS.md, in order to use it commit a file name AGENTS.md to the directory where your Terraform configurations reside.

Installation

Usage with Visual Studio Code

Add the following JSON block to your User Settings (JSON) file in VS Code. You can do this by pressing Ctrl + Shift + P and typing Preferences: Open User Settings (JSON).

More about using MCP server tools in VS Code's agent mode documentation.

jsonCopy code
{
  "mcp": {
    "servers": {
      "terraform": {
        "command": "docker",
        "args": [
          "run",
          "-i",
          "--rm",
          "-e", "TFE_TOKEN=${input:tfe_token}",
          "-e", "TFE_ADDRESS=${input:tfe_address}",
          "hashicorp/terraform-mcp-server:0.5.2"
        ]
      }
    },
    "inputs": [
      {
        "type": "promptString",
        "id": "tfe_token",
        "description": "Terraform API Token",
        "password": true
      },
      {
        "type": "promptString",
        "id": "tfe_address",
        "description": "Terraform Address",
        "password": false
      }
    ]
  }
}

jsonCopy code
{
  "mcp": {
    "servers": {
      "terraform": {
        "command": "docker",
        "args": [
          "run",
          "-i",
          "--rm",
          "hashicorp/terraform-mcp-server:0.2.3"
        ]
      }
    }
  }
}

Optionally, you can add a similar example (i.e. without the mcp key) to a file called .vscode/mcp.json in your workspace. This will allow you to share the configuration with others.

jsonCopy code
{
  "servers": {
    "terraform": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e", "TFE_TOKEN=${input:tfe_token}",
        "-e", "TFE_ADDRESS=${input:tfe_address}",
        "hashicorp/terraform-mcp-server:0.5.2"
      ]
    }
  },
  "inputs": [
    {
      "type": "promptString",
      "id": "tfe_token",
      "description": "Terraform API Token",
      "password": true
    },
    {
      "type": "promptString",
      "id": "tfe_address",
      "description": "Terraform Address",
      "password": false
    }
  ]
}

jsonCopy code
{
  "servers": {
    "terraform": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "hashicorp/terraform-mcp-server:0.2.3"
      ]
    }
  }
}

Usage with Cursor

Add this to your Cursor config (~/.cursor/mcp.json) or via Settings → Cursor Settings → MCP:

jsonCopy code
{
  "mcpServers": {
    "terraform": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e", "TFE_ADDRESS=<<PASTE_TFE_ADDRESS_HERE>>",
        "-e", "TFE_TOKEN=<<PASTE_TFE_TOKEN_HERE>>",
        "hashicorp/terraform-mcp-server:0.5.2"
      ]
    }
  }
}

jsonCopy code
{
  "servers": {
    "terraform": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "hashicorp/terraform-mcp-server:0.2.3"
      ]
    }
  }
}

Usage with Claude Desktop / Amazon Q Developer / Kiro CLI

More about using MCP server tools in Claude Desktop user documentation. Read more about using MCP server in Amazon Q Developer and Kiro CLI.

jsonCopy code
{
  "mcpServers": {
    "terraform": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e", "TFE_ADDRESS=<<PASTE_TFE_ADDRESS_HERE>>",
        "-e", "TFE_TOKEN=<<PASTE_TFE_TOKEN_HERE>>",
        "hashicorp/terraform-mcp-server:0.5.2"
      ]
    }
  }
}

jsonCopy code
{
  "mcpServers": {
    "terraform": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "hashicorp/terraform-mcp-server:0.2.3"
      ]
    }
  }
}

Usage with Claude Code

More about using and adding MCP server tools in Claude Code user documentation

• Local (stdio) Transport

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claude mcp add terraform -s user -t stdio -- docker run -i --rm hashicorp/terraform-mcp-server

• Remote (streamable-http) Transport

shCopy code
# Run server (example)
docker run -p 8080:8080 --rm -e TRANSPORT_MODE=streamable-http -e TRANSPORT_HOST=0.0.0.0 hashicorp/terraform-mcp-server

# Add to Claude Code
claude mcp add --transport http terraform http://localhost:8080/mcp

Usage with Gemini extensions

For security, avoid hardcoding your credentials, create or update ~/.gemini/.env (where ~ is your home or project directory) for storing HCP Terraform or Terraform Enterprise credentials

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# ~/.gemini/.env
TFE_ADDRESS=your_tfe_address_here
TFE_TOKEN=your_tfe_token_here

Install the extension & run Gemini

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gemini extensions install https://github.com/hashicorp/terraform-mcp-server
gemini

Usage with Bob IDE / Shell

More about using and adding MCP servers tools in Bob IDE or Shell Using MCP in Bob.

jsonCopy code
{
  "mcpServers": {
    "terraform": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e", "TFE_ADDRESS=<<PASTE_TFE_ADDRESS_HERE>>",
        "-e", "TFE_TOKEN=<<PASTE_TFE_TOKEN_HERE>>",
        "hashicorp/terraform-mcp-server:0.5.2"
      ],
      "disabled": false
    }
  }
}

jsonCopy code
{
  "mcpServers": {
    "terraform": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "hashicorp/terraform-mcp-server:0.2.3"
      ],
      "disabled": false
    }
  }
}

Install from source

Use the latest release version:

consoleCopy code
go install github.com/hashicorp/terraform-mcp-server/cmd/terraform-mcp-server@latest

Use the main branch:

consoleCopy code
go install github.com/hashicorp/terraform-mcp-server/cmd/terraform-mcp-server@main

jsonCopy code
{
  "mcp": {
    "servers": {
      "terraform": {
        "type": "stdio",
        "command": "/path/to/terraform-mcp-server",
        "env": {
          "TFE_TOKEN": "<<TFE_TOKEN_HERE>>"
        },
      }
    }
  }
}

jsonCopy code
{
  "mcp": {
    "servers": {
      "terraform": {
        "type": "stdio",
        "command": "/path/to/terraform-mcp-server"
      }
    }
  }
}

Building the Docker Image locally

Before using the server, you need to build the Docker image locally:

1. Clone the repository:

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git clone https://github.com/hashicorp/terraform-mcp-server.git
cd terraform-mcp-server

2. Build the Docker image:

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make docker-build

3. This will create a local Docker image that you can use in the following configuration.

bashCopy code
# Run in stdio mode
docker run -i --rm terraform-mcp-server:dev

# Run in streamable-http mode
docker run -p 8080:8080 --rm -e TRANSPORT_MODE=streamable-http -e TRANSPORT_HOST=0.0.0.0 terraform-mcp-server:dev

# Filter tools (optional)
docker run -i --rm terraform-mcp-server:dev --toolsets=registry,terraform
docker run -i --rm terraform-mcp-server:dev --tools=search_providers,get_provider_details

Note: When running in Docker, you should set TRANSPORT_HOST=0.0.0.0 to allow connections from outside the container.

4. (Optional) Test connection in http mode

bashCopy code
# Test the connection
curl http://localhost:8080/health

5. You can use it on your AI assistant as follow:

jsonCopy code
{
  "mcpServers": {
    "terraform": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "terraform-mcp-server:dev"
      ]
    }
  }
}

Available Tools

Check out available tools here :link:

Available Resources

Check out available resources here :link:

Available Metrics

Two kinds of metrics are collected. First, standard HTTP server metrics are added by wrapping the HTTP mux with otelhttp.NewHandler(...). This emits:

1. http.server.request.body.size
2. http.server.response.body.size
3. http.server.request.duration

Second, the MCP server records custom tool metrics around tool execution using MCP hooks (BeforeCallTool / AfterCallTool). These emit:

1. mcp_tool_calls_total
2. mcp_tool_errors_total
3. mcp_tool_duration_seconds

Tool Filtering

Control which tools are available using --toolsets (groups) or --tools (individual):

bashCopy code
# Enable tool groups (default: registry)
terraform-mcp-server --toolsets=registry,terraform

# Enable specific tools only
terraform-mcp-server --tools=search_providers,get_provider_details,list_workspaces

Available toolsets: registry, registry-private, terraform, all, default. See pkg/toolsets/mapping.go for individual tool names. Cannot use both flags together.

Transport Support

The Terraform MCP Server supports multiple transport protocols:

1. Stdio Transport (Default)

Standard input/output communication using JSON-RPC messages. Ideal for local development and direct integration with MCP clients.

2. StreamableHTTP Transport

Modern HTTP-based transport supporting both direct HTTP requests and Server-Sent Events (SSE) streams. This is the recommended transport for remote/distributed setups.

Features:

• Endpoint: http://{hostname}:8080/mcp
• Health Check: http://{hostname}:8080/health
• Environment Configuration: Set TRANSPORT_MODE=http or TRANSPORT_PORT=8080 to enable

Session Modes

The Terraform MCP Server supports two session modes when using the StreamableHTTP transport:

• Stateful Mode (Default): Maintains session state between requests, enabling context-aware operations.
• Stateless Mode: Each request is processed independently without maintaining session state, which can be useful for high-availability deployments or when using load balancers.

To enable stateless mode, set the environment variable:

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export MCP_SESSION_MODE=stateless

Troubleshooting

Corporate Proxy / TLS Inspection (Zscaler, etc.)

If you're behind a corporate proxy that performs TLS inspection (like Zscaler Internet Access), you may see certificate errors:

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tls: failed to verify certificate: x509: certificate signed by unknown authority

Solution: Mount your corporate CA certificate into the container:

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docker run -i --rm \
  -v /path/to/corporate-ca.pem:/etc/ssl/certs/corporate-ca.pem \
  -e SSL_CERT_FILE=/etc/ssl/certs/corporate-ca.pem \
  hashicorp/terraform-mcp-server:0.5.2

For MCP client configurations:

jsonCopy code
{
  "mcpServers": {
    "terraform": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-v", "/path/to/corporate-ca.pem:/etc/ssl/certs/corporate-ca.pem",
        "-e", "SSL_CERT_FILE=/etc/ssl/certs/corporate-ca.pem",
        "-e", "TFE_TOKEN=<>",
        "hashicorp/terraform-mcp-server:0.5.2"
      ]
    }
  }
}

Alternative: Run the binary directly

If Docker is not permitted in your environment, you can install and run the server binary directly, which will use your system's certificate store:

bashCopy code
go install github.com/hashicorp/terraform-mcp-server/cmd/terraform-mcp-server@latest
terraform-mcp-server stdio

Development

Prerequisites

• Go (check go.mod file for specific version)
• Docker (optional, for container builds)

Available Make Commands

Contributing

1. Fork the repository
2. Create your feature branch
3. Make your changes
4. Run tests
5. Submit a pull request

License

This project is licensed under the terms of the MPL-2.0 open source license. Please refer to LICENSE file for the full terms.

Security

For security issues, please contact security@hashicorp.com or follow our security policy.

Support

For bug reports and feature requests, please open an issue on GitHub.

For general questions and discussions, open a GitHub Discussion.