AADSTS Entra Errors — Community Error Code Reference

Free community AADSTS error code lookup for Microsoft Entra ID.
Search by code, scenario or plain English. Severity classification, Conditional Access trigger detection, fix hints — auto-updated from Microsoft Learn.

Author: Antonio Russo · aboutcloud.io

Live: entraerrors.aboutcloud.io
API: https://api.aboutcloud.io/entra-errors

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Architecture

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What It Does

A fully automated, €0/month reference tool that scrapes the Microsoft Entra ID authentication & authorization error codes page, classifies every error by severity and responsible party, adds plain-English descriptions and fix hints, and serves them through a searchable web UI.

349 error codes currently tracked, updated every 6 hours.

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Cloudflare Infrastructure

Worker

Property	Value
Handlers	fetch, scheduled
Compatibility date	2026-04-01
Usage model	Standard

Bindings:

Name	Type	Details
ENTRA_ERRORS	KV Namespace	Error codes, changelog, sync metadata
SEED_SECRET	Secret	Authentication for admin endpoints

Cron Trigger: Every 6 hours — scrapes Microsoft Learn and refreshes KV.

Pages

Property	Value
Deployment type	Direct upload — no Git integration; deploy with wrangler pages deploy web
Tech	Static HTML + Fuse.js 7.0 + custom CSS

KV Keys

Key	Content	Size
entra_errors_codes_v1	All 349 classified error codes (JSON)	~240 KB
entra_errors_changelog_v1	Change log	—
entra_errors_last_sync_v1	Last sync timestamp and stats	< 1 KB
entra_errors_parser_health_v1	Parser health check result	< 1 KB

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API

Base URL: https://api.aboutcloud.io/entra-errors

GET /

Returns full error code catalog.

{
  "meta": {
    "total": 349,
    "last_sync": { "timestamp": "...", "total_codes": 349 },
    "source": "https://learn.microsoft.com/en-us/entra/identity-platform/reference-error-codes"
  },
  "codes": {
    "AADSTS50076": { "...": "..." }
  }
}

GET /stats — Aggregate statistics

GET /changelog — Change log

GET /code/:code — Single error code lookup

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Data Model

{
  "AADSTS50126": {
    "short": "InvalidUserNameOrPassword - Error validating credentials...",
    "plain_english": "InvalidUserNameOrPassword - Error validating credentials due to invalid username or password.",
    "scenario": ["user-account"],
    "severity": "user-error",
    "who_fixes": "user",
    "ca_trigger": false,
    "fix_hint": "User must verify credentials. Admin can reset password in Microsoft Entra admin center.",
    "tags": ["user-error", "user-account"],
    "auto_classified": false,
    "needs_review": false,
    "source_description": "InvalidUserNameOrPassword - Error validating credentials...",
    "first_seen": "2026-04-01T22:47:39.272Z",
    "last_updated": "2026-04-01T22:47:39.272Z"
  }
}

Severity Levels

Severity	Badge	Meaning
user-error	🟢 User Action	User needs to act (wrong password, MFA required, etc.)
admin-config	🟠 Admin Config	Admin needs to fix configuration or policy
developer	🟣 App / Dev	Developer needs to fix code or app registration
microsoft-side	⚪ Microsoft Side	Transient Microsoft-side error — retry

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Frontend Features

• 🔍 Fuse.js full-text search — weighted across code, description, tags, scenarios
• 🏷️ Severity filters — user-error, admin-config, developer, microsoft-side
• 🔴 Conditional Access badge — highlights CA-triggered errors
• 📋 Click-to-copy error codes
• 🌙 Dark theme (Entra-inspired)
• 📊 Live stats bar — total codes, breakdown by severity, CA triggers
• 🔗 Structured data (JSON-LD) for SEO

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Repo Structure

├── api/                  # Worker script
│   ├── worker.js         # Full worker source
│   └── wrangler.toml     # Worker configuration
├── web/                  # Pages frontend
│   ├── index.html        # Full frontend
│   └── wrangler.toml     # Pages configuration
├── scripts/              # Utilities
│   └── scrape_errors.py  # Reference scraper
├── .github/workflows/    # CI/CD
│   └── trivy-scan.yml    # Automated security scanning
├── architecture.svg      # Architecture diagram
├── trivy-badge.svg       # Auto-updated security badge
├── LICENSE
└── README.md

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Quick Start

1. Clone: git clone https://github.com/arusso-aboutcloud/AADSTS-Entra-Errors.git
2. Install Wrangler: npm install -g wrangler
3. Create KV namespace: wrangler kv:namespace create ENTRA_ERRORS
4. Set secret: wrangler secret put SEED_SECRET --config api/wrangler.toml
5. Update api/wrangler.toml with your KV namespace ID, zone, and route
6. Deploy the Worker: wrangler deploy --config api/wrangler.toml
7. Deploy the frontend: wrangler pages deploy web (no Git integration — see Cloudflare Infrastructure above)

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Related aboutcloud.io tools

Other free, open-source Entra ID tools from the same team:

Tool	What it does
Entra RoleLens (source)	Least-privilege Entra ID role finder — task → minimum built-in role
Entra Tracker (source)	Live tracker for Entra ID retirements, breaking changes, and previews
EntraPass (source)	Passkey (FIDO2) readiness scanner for Entra ID tenants
CROSSEC (source)	Microsoft Cloud security crossword game

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License

MIT — see LICENSE for full text.

💼 Using this commercially? MIT licensed and free for personal, educational, and open-source projects.
Building something commercial (SaaS, managed services, reselling)? I'd love to chat —
contact me