msal-singleton-pattern SKILL.md skillA
msal-singleton-pattern from fabioc-aloha/alex_skill_mall is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add fabioc-aloha/alex_skill_mall/msal-singleton-pattern@git:20260728.80a7ab6Pins git:20260728.80a7ab6 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- fabioc-aloha/alex_skill_mall
- Path
plugins/cloud-infrastructure/msal-singleton-pattern/skills/msal-singleton-pattern/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260728.80a7ab6, committed Jul 28, 2026
- Size
- 3,586 bytes
- Repository stars
- 5
- License
- MIT
Time Saved: 1+ hour debugging silent auth failures.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# MSAL Singleton Pattern
**Category**: Azure
**Time Saved**: 1+ hour debugging silent auth failures
**Battle-tested**: Yes — HeadstartWebsite, Next.js + Azure projects
---
## The Problem
Your React/Next.js app uses MSAL.js for Azure AD authentication. Login works, but token refresh fails silently. Sometimes users get logged out randomly. The console shows cryptic "interaction_in_progress" errors.
## Why It Happens
MSAL.js `PublicClientApplication` maintains an internal token cache and tracks in-flight auth requests. Creating multiple instances causes:
- Token cache conflicts (different instances don't share tokens)
- Race conditions on `acquireTokenSilent`
- "interaction_in_progress" errors when two instances try to redirect
## The Rule
**Initialize MSAL once, share the singleton across your entire app**
```typescript
// ❌ BROKEN — new instance on every import/render
function getAuth() {
return new PublicClientApplication(msalConfig);
}
// ✅ CORRECT — module-level singleton with async init
let msalInstance: PublicClientApplication | null = null;
let initPromise: Promise<PublicClientApplication> | null = null;
…Read the whole file at its exact version.
How to install
mdr add fabioc-aloha/alex_skill_mall/msal-singleton-pattern@sha256:a4b2ab786562abd8The line at the top of this page pins the label git:20260728.80a7ab6, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_5l723g3gdob6a2wi)
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Versions
The registry has recorded 1 version of this file, committed on Jul 28, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (3586 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
fabioc-aloha/alex_skill_mall · 5 stars · license MIT · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_5l723g3gdob6a2wi GET https://markdownregistry.com/api/v1/resolve?ref=fabioc-aloha/alex_skill_mall/msal-singleton-pattern GET https://markdownregistry.com/api/v1/blob/a4b2ab786562abd8d71d24e8507598242327c296278c9c5d255c81325b005dfc
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.