⚡ error-to-fix

Paste any error. Get the fix. Instantly.

3,000+ error patterns · 50+ languages · Zero AI latency · Works offline

Why?

You Google an error → scroll through 5 StackOverflow answers → find the fix buried in comment #3.

error-to-fix gives you the fix in < 1 second. Offline. No AI hallucinations. Just a curated, regex-matched database of real fixes.

Install

# Use instantly
npx error-to-fix "your error message"

# Watch mode
your-command 2>&1 | npx error-to-fix --watch

# With explanation
npx error-to-fix "TypeError: x is not a function" --explain

Usage

CLI

# Basic search
error-to-fix "Module not found: Can't resolve './App'"

# Filter by language
error-to-fix "NullReferenceException" --lang csharp

# JSON output (for scripts/editors)
error-to-fix "ENOENT: no such file" --json

Example Output

  ✗ Cannot read properties of undefined (reading 'map') [javascript]

  Fixes:
  1. Add optional chaining: data?.map() or check if array exists before mapping
  2. Initialize state as empty array: useState([]) instead of useState()
  3. Check API response shape — the data might be nested: response.data.items

  Source: MDN / StackOverflow

Features

Watch Mode — Real-time Error Detection

# Pipe any command's output
npm run dev 2>&1 | error-to-fix --watch

# Or pipe build output  
cargo build 2>&1 | error-to-fix --watch

Automatically detects errors in terminal output and shows fixes inline.

Auto Language Detection

# No --lang needed — detected automatically
error-to-fix "Traceback (most recent call last): KeyError: 'name'"
# → Detected: python

error-to-fix "NullReferenceException: Object reference not set"
# → Detected: csharp

Explain Mode

error-to-fix "Cannot read properties of undefined" --explain

  ✗ Cannot read properties of undefined [javascript]

  Why: You're accessing a property on a variable that is undefined.
  This usually happens when data hasn't loaded yet or a key is misspelled.

  Fixes:
  1. Add optional chaining: obj?.property
  2. Check if variable exists before accessing
  3. Initialize with default value

Platforms

| Platform | Status | How to Use | |----------|--------|------------| | 💻 CLI | ✅ Published | npx error-to-fix "your error" | | 🌐 Website | Ready | errortofix.dev | | 📝 VS Code | Ready | Search "error-to-fix" in extensions | | 🌎 Chrome Extension | Ready | Highlights errors on any page | | 🔧 NuGet Analyzer | Ready | Real-time fixes in C#/Rider |

Languages & Tools Covered

Languages: JavaScript, TypeScript, Python, C#, Java, Go, Rust, Swift, Kotlin, Ruby, PHP, Dart, Elixir, Scala

Frameworks: React, Angular, Vue, Svelte, Next.js, Express, Django, Flask, Spring Boot, ASP.NET, Rails

DevOps: Docker, Kubernetes, Terraform, AWS CLI, Azure, GCP, Nginx, Git, GitHub Actions, CI/CD

Databases: PostgreSQL, MySQL, MongoDB, Redis, SQLite, DynamoDB, Elasticsearch

Package Managers: npm, pip, cargo, dotnet, composer, gem, go mod

How It Works

User input: "TypeError: Cannot read properties of undefined (reading 'length')"
     ↓
Regex matching against 3,010 curated patterns
     ↓
Ranked by match score (pattern coverage / query length)
     ↓
Top 3 results with fixes returned in <1ms

No AI. No API calls. No internet required. The entire database ships with the package (~1MB).

Database Format

Each error entry:

{
  "pattern": "Cannot read properties of (undefined|null)",
  "title": "Cannot read properties of undefined/null",
  "lang": "javascript",
  "fixes": [
    "Use optional chaining: obj?.property",
    "Add null check before accessing the property",
    "Ensure the variable is initialized before use"
  ],
  "source": "MDN / StackOverflow"
}

Contributing

We need your help to grow the database!

Add an error in 2 minutes:

1. Fork this repo
2. Edit packages/shared/errors-{language}.json
3. Add your pattern + fixes
4. Submit a PR

See CONTRIBUTING.md for the full guide.

Programmatic Use

import { search } from 'error-to-fix';

const results = search("ECONNREFUSED 127.0.0.1:5432");
// [{ title: "PostgreSQL connection refused", fixes: [...], lang: "postgresql" }]

Tech Stack

| Component | Tech | |-----------|------| | CLI | Node.js, TypeScript, Commander, Chalk | | Website | Next.js 15, Tailwind CSS 4 | | VS Code Extension | VS Code Extension API | | Chrome Extension | Manifest V3, Service Worker | | NuGet Analyzer | .NET 9, Roslyn | | Database | 3,010 curated JSON patterns |

Roadmap

• [x] Auto-detect language from error format
• [x] --watch mode: monitor terminal output and suggest fixes in real-time
• [ ] Fuzzy search for partial/typo matches
• [ ] Community voting on fix quality
• [ ] VS Code: inline fix suggestions on error squiggles
• [ ] 10,000+ patterns by end of 2026

License

MIT © Satyam Thakur