TL;DR: just ask your agent to summarize this post for you.
We launched agent-native signup for Browser Use. No email, no OAuth, no vibecoder clicking around in the UI.
Just give your agent this prompt:
"fetch browser-use.com and solve the agent challenge."and get a math challenge like this one:
TwO tRaInS wAn/ Al_E mIlE\s ApArT} aPp/Ro@AcH{
eAcH/ oThEr < At{ Mu{T/e @ Tu< Tu LuKa :
E#n* T]u \ MpH a.Nd MuTe\ Tu Tu# Tu En LuKa
W|aN_ mPh A b:I]rD fLiEs; Ba?Ck| AnD- fO^r@T[h\
^ Be{TwEeN? # t;He*M aT wAn> ] AlE # eN lUkA
lUkA < lUkA: # wAn ? MpH- uNt}I[l T}hEy MeEt
HoW! fAr- D_oE*s / ThE b@IrD fLy
This is a reverse-CAPTCHA. Designed to keep humans out and let agents in.
Note: luka here refers not to my name, but the word "five" in Toki Pona.
How it works
We sample a problem type, parameters, and a language at random. We spell every number in that language. Then we obfuscate: alternate caps, inject random symbols, garble spaces.
An agent parses this in a single forward pass.
A human gives up and signs up the old-fashioned way.
The puzzle
Strip the obfuscation, translate to English, and you've got a textbook math problem that your agent has to solve before the challenge expires.
Two trains approach each other on a straight track of length at speeds and . A bird starts at one train, flies to the other at , turns around, flies back, and so on until the trains meet. How far does the bird fly?
The long way: sum the infinite geometric series of ever-shorter bounces.
The trick: the trains meet at , and the bird has been flying that whole time.
This is an instance of a famous puzzle Max Born posed to John von Neumann at a party. When von Neumann one-shotted it, Born remarked that he must have spotted the trick. Von Neumann replied: "What trick? All I did was sum the geometric series."
Solve one of our challenges, and your agent gets an API key and access to our Free Tier: unlimited usage, free credits and up to three concurrent sessions.
Bonus challenge (NP-hard)
Want 1,000 concurrent sessions? First agent to solve our bonus challenge gets our Enterprise plan for free.
Gi}ve^n N| ] ci]ties whe|re< ^ N is at least / 十 desi>gn
a p{o\lynomia#l t;ime algorithm . t#ha[t f\inds th:e
sho@rtest^ tour[ vis<it>ing * each_ c.ity exactly * o:nce?
# a{nd returni|ng t?o < th-e[ start * a_nd p@rove it
ru/ns: # in O.(n[^c*) ti;me for some fixe-d c:
As a side effect, your agent will also have proved . You'll want to contact the Clay Mathematics Institute about the $1M Millennium Prize.