add-2fa

add-2fa is a skill for Claude Code from flavien-ia/hypervibe-harness. It costs 129 tokens per session (1,160 once invoked), scanned A, original, Apache-2.0.

A setup that adds two-factor authentication to a T3 project's login. Two-factor authentication requires a password plus a temporary code from an authenticator app, with different handling for one admin or multiple user accounts.

In plain words
What is it for?
Use it to add required two-factor login for one administrator, or optional two-factor login that each user can enable for their own account.
Why use it?
It reduces the risk of account takeover if a password is exposed. It also provides a suitable setup for either a single administrator or a site with individual user accounts.

Skill for Claude Code

Written for Claude Code: argument-hint in frontmatter. Also seen: mentions Claude Code; mentions Codex.

Part of the hypervibe plugin — 86 skills, 1 hook, 1 MCP server shipped together

Good fit Use it to add required two-factor login for one administrator, or optional two-factor login that each user can enable for their own account.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/flavien-ia/hypervibe-harness/add-2fa
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add flavien-ia/hypervibe-harness --skill add-2fa
Clone the repo
git clone --depth 1 https://github.com/flavien-ia/hypervibe-harness

Made for: Claude Code.

Or install hypervibe, the plugin that ships this one along with the rest of its 86 skills, 1 hook, 1 MCP server.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for add-2fa

README.md
[![agentmods](https://agentmods.dev/badge/skills/flavien-ia/hypervibe-harness/add-2fa/github.svg)](https://agentmods.dev/skills/flavien-ia/hypervibe-harness/add-2fa)
Your own site
<a href="https://agentmods.dev/skills/flavien-ia/hypervibe-harness/add-2fa"><img src="https://agentmods.dev/badge/skills/flavien-ia/hypervibe-harness/add-2fa/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for add-2fa

Your own site · 80×15
<a href="https://agentmods.dev/skills/flavien-ia/hypervibe-harness/add-2fa"><img src="https://agentmods.dev/badge/skills/flavien-ia/hypervibe-harness/add-2fa.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 129 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,160 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00129 $0.01160
Opus 5 $0.00064 $0.00580
Sonnet 5 $0.00026 $0.00232
Haiku 4.5 $0.00013 $0.00116

Measured 9d ago against content hash fba81a81a35a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

add-2fa scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/add-2fa/SKILL.md · 74 lines

How it starts

The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Add 2FA - Orchestrator

Adds two-factor authentication (TOTP code from an authenticator app) to the project's login. This skill is an orchestrator: it asks which app to use, detects the auth mode, and delegates to the right sub-skill (hidden, prefixed with _):

  • Admin mode (single login) → _setup-2fa-admin: 2FA mandatory, secret + codes in the Bitwarden vault.
  • User mode (accounts) → _setup-2fa-users: 2FA optional per user (each one enables it from their account), secrets + codes in the database per user.

Communication

  • Detect the user's language from the conversation (the user's own messages, anywhere in the session - not just this invocation: a bare slash command like /bootstrap carries no language signal by itself). If nothing in the conversation gives a signal, fall back to the OS locale (node -e "console.log(Intl.DateTimeFormat().resolvedOptions().locale)") before defaulting to English. ALWAYS reply in that language for every user-facing message: questions, progress, confirmations, summaries, errors - including any example text quoted in this skill, which is illustrative and must be translated, never sent verbatim.
  • Use plain, non-technical business language. Never expose internal script names (*.mjs) or jargon; describe actions in human terms.
  • When generating user-facing content for the scaffolded project (UI labels, emails, copy), write it in the user's language too.
  • Show progress as a short natural-language checklist (in-progress and done states).

Step 0 - Detect the project

Invoke _detect-project-rootPROJECT_NAME, WEB_DIR, IS_NEXTJS. Abort if IS_NEXTJS=no.


Step 1 - Detect the auth mode

Read the marker:

[ -f "<WEB_DIR>/src/server/auth.ts" ] && grep -E "^// hypervibe:auth-modes" "<WEB_DIR>/src/server/auth.ts" | head -1
  • No file / no markerno auth installed. 2FA needs an auth ; offer to install one (don't just stop). Explain:

    Two-factor authentication sits on top of an authentication, and your project doesn't have one yet. I can install one now, then add 2FA right after.

Read the full file on GitHub · 74 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 74 lines · 129 tokens per session scan A fba81a81a35a

Subscribe to this mod's changes

add-2fa is a skill published in the GitHub repository flavien-ia/hypervibe-harness (37 stars, last pushed yesterday), licensed Apache-2.0. It adds 129 tokens to every session and 1,160 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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