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.

$Infracost Server MCP server$

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
Access predefined usage YAML files for cost estimation

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

MCP Resources

The server provides predefined Infracost usage YAML files as MCP resources:

infracost://usage/small - Small usage defaults ($5/month) for development environments
infracost://usage/medium - Medium usage defaults ($10/month) for staging environments
infracost://usage/large - Large usage defaults ($20/month) for production environments
infracost://usage/example - Example template showing how to customize usage values

These resources can be used to understand Infracost usage files or as templates for creating custom usage configurations. Claude can access these resources directly to help you set up cost estimation with realistic usage patterns.

Project Structure

src/ - TypeScript source code
dist/ - Compiled JavaScript output (created by npm run build)
resources/ - Predefined Infracost usage YAML files
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

License

MIT

infracost_mcp