Infracost MCP Server

MCP server that lets Claude interact with Infracost for Terraform cost estimation and cloud governance. Works with Claude Desktop and Claude Code.

What it does

• Generate cost breakdowns for Terraform configurations
• Compare costs between different configs or branches
• Create and manage tagging policies in Infracost Cloud
• Set up cost guardrails that block expensive PRs
• Post cost comments to GitHub/GitLab/Azure/Bitbucket PRs
• Upload custom properties for resource classification

Prerequisites

• Node.js >= 18
• Infracost CLI (for cost estimation tools)
• Infracost service token from Infracost Cloud > Org Settings > API tokens

Installation

git clone <repo-url> infracost_mcp
cd infracost_mcp
npm install
npm run build

Configuration

Create a .env file in the project root:

INFRACOST_SERVICE_TOKEN=ics_v1_your_token_here
INFRACOST_ORG=your_org_slug

Get your service token from the Infracost Cloud dashboard under Org Settings > API tokens.

Usage

With Claude Code

The repo includes .mcp.json and .claude/agents/ so it works out of the box - just open the project in Claude Code and the Infracost tools will be available.

With Claude Desktop

Add to your Claude Desktop config file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json
• Windows: %APPDATA%/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "infracost": {
      "command": "node",
      "args": ["/absolute/path/to/infracost_mcp/dist/index.js"],
      "env": {
        "INFRACOST_SERVICE_TOKEN": "ics_v1_your_token"
      }
    }
  }
}

Restart Claude Desktop after updating the config.

Examples

Natural Language Queries

Ask Claude things like:

Cost Estimation:

• "What's the monthly cost of my Terraform in ./infrastructure?"
• "Show me a cost breakdown for ./terraform/prod in table format"
• "Generate an HTML cost report and save it to report.html"
• "Upload the cost estimate from infracost.json to Infracost Cloud"

Cost Comparison:

• "Compare costs between ./staging and ./prod configs"
• "What's the cost difference if I switch from t3.medium to t3.large?"
• "Show me cost changes between the current branch and main"

Tagging Policies:

• "Create a tagging policy that requires Environment and Owner tags"
• "List all tagging policies for my organization"
• "Add a tagging policy that allows only 'dev', 'staging', 'prod' for Environment tags"
• "Update the tagging policy to also require a CostCenter tag"

Cost Guardrails:

• "Set up a guardrail that blocks PRs adding more than $200/month"
• "Create a guardrail that warns when total infrastructure cost exceeds $10k/month"
• "Block PRs with cost increases over 25% for my production repo"
• "List all active guardrails"

Pull Request Integration:

• "Post the cost estimate from infracost.json to GitHub PR #123 in owner/repo"
• "Add a cost comment to the current GitLab merge request"

JSON Examples

Generate cost breakdown:

{
  "path": "./terraform/prod",
  "format": "json",
  "outFile": "cost-estimate.json"
}

Compare configurations:

{
  "path": "./terraform/current",
  "compareTo": "./terraform/baseline",
  "format": "diff"
}

Create tagging policy:

{
  "name": "Required tags policy",
  "prComment": true,
  "blockPr": true,
  "tags": [
    {
      "key": "Environment",
      "mandatory": true,
      "valueType": "LIST",
      "allowedValues": ["dev", "staging", "prod"]
    },
    {
      "key": "Owner",
      "mandatory": true,
      "valueType": "REGEX",
      "allowedRegex": "^[a-z]+\\.[a-z]+@company\\.com$"
    }
  ]
}

Create cost guardrail:

{
  "name": "Production cost limit",
  "scope": {
    "type": "REPO",
    "repositories": ["myorg/prod-infrastructure"]
  },
  "increasePercentThreshold": 10,
  "totalThreshold": 50000,
  "blockPullRequest": true,
  "commentOnPullRequest": true
}

See docs/EXAMPLES.md for more detailed examples.

Available Tools

CLI Tools (require Infracost CLI)

• infracost_breakdown - Generate cost breakdown for Terraform infrastructure
• infracost_diff - Show cost differences between two configurations
• infracost_output - Combine and format Infracost JSON files
• infracost_upload - Upload cost estimates to Infracost Cloud
• infracost_comment - Post cost comments to pull requests

Cloud API Tools (require service token)

Tagging Policies:

• infracost_cloud_list_tagging_policies - List all tagging policies
• infracost_cloud_get_tagging_policy - Get a specific tagging policy
• infracost_cloud_create_tagging_policy - Create a new tagging policy
• infracost_cloud_update_tagging_policy - Update an existing tagging policy
• infracost_cloud_delete_tagging_policy - Delete a tagging policy

Guardrails:

• infracost_cloud_list_guardrails - List all guardrails
• infracost_cloud_get_guardrail - Get a specific guardrail
• infracost_cloud_create_guardrail - Create a cost guardrail
• infracost_cloud_update_guardrail - Update an existing guardrail
• infracost_cloud_delete_guardrail - Delete a guardrail

Custom Properties:

• infracost_cloud_upload_custom_properties - Upload custom property values via CSV

Project Structure

• src/ - TypeScript source code
• dist/ - Compiled JavaScript output (created by npm run build)
• docs/ - Additional documentation and examples
• .claude/ - Claude Code agent configuration

Development

npm run build   # Compile TypeScript
npm run watch   # Watch mode for development
npm start       # Run the MCP server

Troubleshooting

CLI tools not working:

• Verify Infracost CLI is installed: infracost --version
• Ensure INFRACOST_SERVICE_TOKEN is set correctly

Cloud API errors:

• Check that your service token has the necessary permissions
• Verify the organization slug is correct

Server not connecting:

• Ensure the path to dist/index.js is absolute in your MCP config
• Restart Claude Desktop after making config changes
• Check that npm run build completed successfully

No resources found:

• Run terraform init in your Terraform directory first
• Verify the path to your Terraform files is correct

Resources

• Infracost Documentation
• Infracost Cloud API
• Model Context Protocol

License

MIT