macOS
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brew install rsc_2falocal Homebrew formula metadata
brew / rank 9355
Install rsc_2fa with Homebrew
Two-factor authentication on the command-line. Version 1.2.0 via Homebrew; verified 2026-09-12.
install
Additional install commands
overview
Package summary
Two-factor authentication on the command-line
Project links
Commands and aliases
- 2fa
history
Project history and usage
2fa is a command-line authentication-code generator for named TOTP and HOTP secrets.
Project history
Russ Cox created 2fa as a compact command-line two-factor authentication agent written in Go. The project supports both time-based and counter-based one-time passwords and keeps its interface centered on adding, listing, and querying named keys.
Adoption history
The repository's focused scope and small codebase made 2fa a recognizable Unix-style authenticator among command-line users. Its official GitHub repository has accumulated substantial community interest, while the input records Homebrew distribution.
How it is used
Use `2fa -add name` to enroll a secret, `2fa -list` to list stored names, and `2fa name` to print a current code. With no arguments it prints codes for all time-based keys; `-clip` also copies a code to the clipboard.
Why package nerds care
2fa exemplifies the small, composable command-line security tool: enrollment and code generation fit into scripts and terminal workflows. Package users should note its deliberate simplicity also means secrets are stored unencrypted in a plain text file.
Timeline
- 2014: The earliest public repository history dates to the project's initial Go implementation.
- 2018: The repository's compact modern form added module metadata and vendored clipboard support.
Related projects
- The utility implements the TOTP and HOTP styles of one-time passwords and can optionally integrate with the system clipboard.
Sources
- https://github.com/rsc/2fa#readme
- https://pkg.go.dev/rsc.io/2fa
- source_facts.package-manager
security posture
Risk level: green
narrow executable package without higher-risk signals.
Risk classifier
green risk · low confidence · appliance
Why
- narrow executable package without higher-risk signals
Signals
- metadata:no-higher-risk-signals
Install behavior
- No Homebrew post-install hook is recorded in formula metadata.
- Homebrew bottle metadata is available for 12 platform targets.
- Build metadata lists 1 build dependencies.
Recommended review
Before unattended agent use, check whether the tool reads plaintext credentials, writes remote state, publishes artifacts, or shells out to plugins.
local files
Configuration and credential file locations
These source-backed paths show where this package keeps local settings or durable credentials. Automic Vault can use them as review targets for secret scanning, migration, and command approval.
Credential files
Credential-bearing paths to review before unattended agent runs.
- Unix
~/.2fa
executables
Installed executables
| Command | Kind | Exposure | Note |
|---|---|---|---|
2fa | cli | global executable |
freshness
Version and freshness
These signals separate page generation age, package-manager activity, and upstream release comparison. Version lag is warned only when an evidence URL and comparable versions are present.
page generated2026-09-19
manager version1.2.0
manager updated2026-09-12
local dataok
upstreamcurrent
latest detectedv1.2.0
- okNo freshness warnings were generated.
install metadata
Package metadata
| Package key | brew:rsc_2fa |
|---|---|
| Version | 1.2.0 |
| Package manager | Homebrew |
| Package manager page | https://formulae.brew.sh/formula/rsc_2fa |
| Homepage | https://pkg.go.dev/rsc.io/2fa |
| Repository | https://github.com/rsc/2fa |
| Upstream docs | https://pkg.go.dev/rsc.io/2fa |
| License | BSD-3-Clause |
| Source archive | https://github.com/rsc/2fa/archive/refs/tags/v1.2.0.tar.gz |
| Last updated | 2026-09-12T11:12:59Z |
| Pulse | updated |
| Build dependencies | go |
| Bottle | available (on arm64_big_sur, arm64_linux, arm64_monterey, arm64_sequoia, arm64_sonoma, arm64_tahoe, arm64_ventura, big_sur, monterey, sonoma, ventura, x86_64_linux) |
| Homebrew post-install | not defined |
| Service | none declared |
registry facts
Source database details
| Source Database | Homebrew formula API |
|---|---|
| Tap | homebrew/core |
| Full Name | rsc_2fa |
| Version Scheme | 0 |
| Revision | 0 |
| Bottle Stable Root URL | https://ghcr.io/v2/homebrew/core |
| Deprecated | no |
| Disabled | no |
| Keg Only | no |
| URL Keys |
|
source trail
Generated from repository data
This page is generated by av-web from the private package SQLite artifact built by scripts/generate-pkg-sqlite.py.
Combined YAML source
View the package source record on GitHub.
Used sources
- Geiger risk classifier
- cross-ecosystem install command graph
- curated configuration and credential file locations
- curated package history
- package relationship graph
- package version freshness
- package-page enrichment
- pkg.so package database
- pkgdb category and tag curation