fot-libraries

name	fot-libraries
description	Use when you need a utility library, are about to install an external npm package, or when an @f-o-t library is missing a feature or has a bug. Triggers on any "bun add", "npm install", or reaching for third-party packages for functionality that could live in @f-o-t/libraries.

@f-o-t/libraries

Overview

The F-O-T/libraries monorepo is the first place to check before installing any external dependency. When a needed feature is missing, request it — don't import from npm.

Core principle: Enrich @f-o-t libraries instead of adding external dependencies. Even when you must use a workaround today, open an issue for discussion so the library grows.

When to Use

Always use this skill before:

• Running bun add <some-external-package>
• Importing from a library not already in the project
• Needing utility functionality (QR codes, crypto, money, content, markdown, etc.)

Also use when:

• An @f-o-t library covers the domain but is missing a method → request the feature + open discussion issue
• An @f-o-t library has a bug → report it
• You find yourself writing a helper that logically belongs in @f-o-t → propose it

Available Libraries

Check the root package.json catalog under "fot" for currently installed versions.

Package	Domain
@f-o-t/qrcode	QR code generation as PNG Uint8Array
@f-o-t/money	BRL currency with scale 6 (micro-precision)
@f-o-t/condition-evaluator	Condition evaluation engine
@f-o-t/content-analysis	Content analysis utilities
@f-o-t/markdown	Markdown processing
@f-o-t/spelling	Spelling utilities
@f-o-t/crypto	PKCS#12, CMS/PKCS#7, hashing, PEM
@f-o-t/asn1	ASN.1 DER encoding/decoding
@f-o-t/digital-certificate	Brazilian A1 certificate handling
@f-o-t/e-signature	PAdES PDF signing (ICP-Brasil)

Discover all published packages:

npm search @f-o-t
gh repo view F-O-T/libraries

Decision Flow

digraph fot_flow {
    "Need a utility?" [shape=diamond];
    "Check @f-o-t catalog" [shape=box];
    "@f-o-t covers it fully?" [shape=diamond];
    "Use @f-o-t package" [shape=box];
    "@f-o-t covers domain but missing feature?" [shape=diamond];
    "Use workaround + open discussion issue on F-O-T/libraries" [shape=box];
    "Fits @f-o-t domain but no lib yet?" [shape=diamond];
    "Request new library on F-O-T/libraries" [shape=box];
    "Use external package + open discussion issue" [shape=box];

    "Need a utility?" -> "Check @f-o-t catalog";
    "Check @f-o-t catalog" -> "@f-o-t covers it fully?";
    "@f-o-t covers it fully?" -> "Use @f-o-t package" [label="yes"];
    "@f-o-t covers it fully?" -> "@f-o-t covers domain but missing feature?" [label="no"];
    "@f-o-t covers domain but missing feature?" -> "Use workaround + open discussion issue on F-O-T/libraries" [label="yes"];
    "@f-o-t covers domain but missing feature?" -> "Fits @f-o-t domain but no lib yet?" [label="no"];
    "Fits @f-o-t domain but no lib yet?" -> "Request new library on F-O-T/libraries" [label="yes"];
    "Fits @f-o-t domain but no lib yet?" -> "Use external package + open discussion issue" [label="no"];
}

Requesting a Feature (Missing Method/API)

REQUIRED SUB-SKILL: Use feature-request on repo F-O-T/libraries

gh issue create --repo F-O-T/libraries \
  --title "[package-name] Add <method/feature>" \
  --label "enhancement" \
  --body "..."

What to include:

• The exact API you need (method signature, input/output types)
• Your use case — why it belongs in @f-o-t
• Example usage showing what you want to call
• The workaround you're using in the meantime (if any)

Example:

Title: [@f-o-t/qrcode] Add browser-compatible dataURL helper

Use case: Profile 2FA TOTP setup needs to display QR in a React app.
generateQrCode() returns Uint8Array (Bun/server). Browser needs a data URL.

Desired API:
  import { qrCodeToDataUrl } from "@f-o-t/qrcode";
  const src = qrCodeToDataUrl(totpUri, { size: 180 });
  // returns "data:image/png;base64,..."

Workaround (current): btoa(String.fromCharCode(...generateQrCode(uri)))

Opening a Discussion Issue (Enrichment Idea)

Even when you're using a workaround or an external package temporarily, always open a discussion issue if there's a clear enrichment opportunity for @f-o-t:

gh issue create --repo F-O-T/libraries \
  --title "[discussion] <domain> - <what could be added>" \
  --label "discussion" \
  --body "..."

Use this for:

• Workarounds you wrote inline that should be a proper API
• External packages you installed that could be replaced
• Patterns repeated across projects that belong in a shared lib

Reporting a Bug

REQUIRED SUB-SKILL: Use debug-and-report on repo F-O-T/libraries

gh issue create --repo F-O-T/libraries \
  --title "[package-name] Bug: <what's broken>" \
  --label "bug"

Red Flags — STOP Before Installing

Thought	Action
"I need a QR code library"	Check @f-o-t/qrcode
"I need a currency formatter"	Check @f-o-t/money
"I'll just bun add this package"	Stop — check @f-o-t catalog first
"This library is missing X method"	Request it + open discussion issue
"I wrote a helper for this inline"	Open discussion issue to move it to @f-o-t

Installing an @f-o-t Package

1. Add to root package.json catalog under "fot":

   "@f-o-t/qrcode": "1.0.1"
   

2. Add to the app's package.json dependencies:

   "@f-o-t/qrcode": "catalog:fot"
   

3. Run bun install