gitwtfhub

wtf is captcha?

moul/captcha — explained in plain English

Analysis updated 2026-07-17 · repo last pushed 2026-06-18

★ 13GoAudience · developerComplexity · 2/5ActiveSetup · easy

TL;DR

A command-line tool that generates text-based CAPTCHA puzzles, like math problems or ASCII art, to verify you're a real person right in your terminal.

Mindmap

mindmap
  root((repo))
    What it does
      Terminal CAPTCHAs
      Human verification
      No web images
    Tech stack
      Go
      CLI tool
    Use cases
      CLI auth checks
      Prevent bot abuse
      Experiment with CAPTCHAs
    Audience
      CLI developers
      Security tinkerers
    Engines
      Math puzzles
      ASCII banner text

Code map

Detail Auto

An interactive map of this repo's files and how they connect — its source is parsed live in your browser. Click Visualize to build it.

filefunction / class

Why would anyone build with this?

REASON 1

Add a human-verification check to a CLI tool without third-party services.

REASON 2

Challenge suspicious requests in a terminal application to prevent automated abuse.

REASON 3

Experiment with CAPTCHA mechanics for learning or fun.

REASON 4

Embed a lightweight text puzzle in any script you already run from the command line.

What's in the stack?

Go

How it stacks up

moul/captchakleimer/vpn_over_sshroyp888/sola-bot
Stars131313
LanguageGoGoGo
Last pushed2026-06-18——
MaintenanceActive——
Setup difficultyeasyhardhard
Complexity2/54/54/5
Audiencedeveloperops devopsdeveloper

Figures from each repo's GitHub metadata at analysis time.

How do you spin it up?

Difficulty · easy Time to first run · 5min

Yoink these prompts

Prompt 1
Show me how to install and run moul/captcha to generate a math-based CAPTCHA.
Prompt 2
Help me integrate moul/captcha into my own CLI tool for human verification.
Prompt 3
Explain the difference between the math engine and banner engine in moul/captcha.
Prompt 4
Write a script that uses moul/captcha to block automated requests to my terminal app.

Frequently asked questions

wtf is captcha?

A command-line tool that generates text-based CAPTCHA puzzles, like math problems or ASCII art, to verify you're a real person right in your terminal.

What language is captcha written in?

Mainly Go. The stack also includes Go.

Is captcha actively maintained?

Active — commit in last 30 days (last push 2026-06-18).

How hard is captcha to set up?

Setup difficulty is rated easy, with roughly 5min to a first successful run.

Who is captcha for?

Mainly developer.

View the repo → Decode another repo

This repo across BitVibe Labs

Don't trust strangers blindly. Verify against the repo.

Other repos in this lane