Skip to main content

​
Overview

The get_missing_envs tool identifies every environment variable that is used in code but has no definition anywhere and no default value. These variables will cause runtime crashes when the application tries to access them.

​
Parameters

​
projectPath
string
Path to the project directory. Defaults to current working directory.

​
Response

​
missing
array
required
Array of missing environment variables
​
totalMissing
number
required
Total number of missing variables
​
willCauseRuntimeCrash
number
required
Number of variables that will definitely cause runtime crashes (critical danger level)
​
metadata
object
required
Scan metadata

​
Example Response

{
  "missing": [
    {
      "name": "API_KEY",
      "usages": [
        {
          "file": "src/api/client.ts",
          "line": 12,
          "context": "const apiKey = process.env.API_KEY;"
        },
        {
          "file": "src/services/external-api.ts",
          "line": 25,
          "context": "headers: { 'X-API-Key': process.env.API_KEY }"
        },
        {
          "file": "src/middleware/auth.ts",
          "line": 8,
          "context": "if (!process.env.API_KEY) throw new Error();"
        }
      ],
      "usageCount": 8,
      "languages": ["typescript"],
      "dangerLevel": "critical"
    },
    {
      "name": "WEBHOOK_SECRET",
      "usages": [
        {
          "file": "src/webhooks/handler.ts",
          "line": 45,
          "context": "const secret = process.env.WEBHOOK_SECRET;"
        }
      ],
      "usageCount": 2,
      "languages": ["typescript"],
      "dangerLevel": "high"
    }
  ],
  "totalMissing": 2,
  "willCauseRuntimeCrash": 1,
  "metadata": {
    "projectPath": "/Users/dev/my-project",
    "scannedFiles": 156,
    "cacheHit": false,
    "duration": 198
  }
}

​
Usage Example

AI assistants can call this tool to identify missing variables before deployment: 
{
  "name": "get_missing_envs",
  "arguments": {
    "projectPath": "/path/to/project"
  }
}
Minimal call (uses current directory): 
{
  "name": "get_missing_envs",
  "arguments": {}
}

​
Use Cases

  • Pre-Deployment Check: Ensure all required variables are defined before deploying
  • Onboarding: Help new developers set up their environment correctly
  • CI/CD: Validate environment configuration in continuous integration
  • Crash Prevention: Identify variables that will cause runtime failures
  • Environment Migration: Ensure all variables are migrated when moving between environments

​
Error Prevention

Variables reported by this tool will cause one of these errors at runtime:
  • TypeError: Cannot read property 'X' of undefined
  • ReferenceError: VARIABLE_NAME is not defined
  • Application crashes when accessing undefined environment variables
  • Silent failures if code doesn’t validate environment variables
The dangerLevel field indicates severity:
  • critical: Used in 3+ locations, will likely crash multiple parts of the application
  • high: Used in 1-2 locations, will crash specific functionality

Build docs developers (and LLMs) love

Get started for freeTalk to us