After a team mem­ber sum­moned Copilot to cor­rect a typo in a PR of mine, Copilot edited my PR de­scrip­tion to in­clude and ad for it­self and Raycast.

This is hor­rific. I knew this kind of bull­shit would hap­pen even­tu­ally, but I did­n’t ex­pect it so soon.

Here is how plat­forms die: first, they are good to their users; then they abuse their users to make things bet­ter for their busi­ness cus­tomers; fi­nally, they abuse those busi­ness cus­tomers to claw back all the value for them­selves. Then, they die.

Every ChatGPT mes­sage trig­gers a Cloudflare Turnstile pro­gram that runs silently in your browser. I de­crypted 377 of these pro­grams from net­work traf­fic and found some­thing that goes be­yond stan­dard browser fin­ger­print­ing.

The pro­gram checks 55 prop­er­ties span­ning three lay­ers: your browser (GPU, screen, fonts), the Cloudflare net­work (your city, your IP, your re­gion from edge head­ers), and the ChatGPT React ap­pli­ca­tion it­self (__reactRouterContext, load­er­Data, client­Boot­strap). Turnstile does­n’t just ver­ify that you’re run­ning a real browser. It ver­i­fies that you’re run­ning a real browser that has fully booted a spe­cific React ap­pli­ca­tion.

A bot that spoofs browser fin­ger­prints but does­n’t ren­der the ac­tual ChatGPT SPA will fail.

The Turnstile byte­code ar­rives en­crypted. The server sends a field called turn­stile.dx in the pre­pare re­sponse: 28,000 char­ac­ters of base64 that change on every re­quest.

The outer layer is XOR’d with the p to­ken from the pre­pare re­quest. Both travel in the same HTTP ex­change, so de­crypt­ing it is straight­for­ward:

outer = json.loads(bytes(

base64de­code(dx)[i] ^ p_­to­ken[i % len(p_­to­ken)]

for i in range(len(base64de­code(dx)))

# → 89 VM in­struc­tions

Inside those 89 in­struc­tions, there is a 19KB en­crypted blob con­tain­ing the ac­tual fin­ger­print­ing pro­gram. This in­ner blob uses a dif­fer­ent XOR key that is not the p to­ken.

Initially I as­sumed this key was de­rived from per­for­mance.now() and was truly ephemeral. Then I looked at the byte­code more care­fully and found the key sit­ting in the in­struc­tions:

[41.02, 0.3, 22.58, 12.96, 97.35]

The last ar­gu­ment, 97.35, is the XOR key. A float lit­eral, gen­er­ated by the server, em­bed­ded in the byte­code it sent to the browser. I ver­i­fied this across 50 re­quests. Every time, the float from the in­struc­tion de­crypts the in­ner blob to valid JSON. 50 out of 50.

The full de­cryp­tion chain re­quires noth­ing be­yond the HTTP re­quest and re­sponse:

1. Read p from pre­pare re­quest

2. Read turn­stile.dx from pre­pare re­sponse

3. XOR(base64decode(dx), p) → outer byte­code

4. Find the 5-arg in­struc­tion af­ter the 19KB blob → last arg is the key

5. XOR(base64decode(blob), str(key)) → in­ner pro­gram (417-580 VM in­struc­tions)

The key is in the pay­load.

Each in­ner pro­gram uses a cus­tom VM with 28 op­codes (ADD, XOR, CALL, BTOA, RESOLVE, BIND_METHOD, JSON_STRINGIFY, etc.) and ran­dom­ized float reg­is­ter ad­dresses that change per re­quest. I mapped the op­codes from the SDK source (sdk.js, 1,411 lines, de­ob­fus­cated).

The pro­gram col­lects 55 prop­er­ties. No vari­a­tion across 377 sam­ples. All 55, every time, or­ga­nized into three lay­ers:

Storage (5): stor­age, quota, es­ti­mate, setItem, us­age. Also writes the fin­ger­print to lo­cal­Stor­age un­der key 6f376b6560133c2c for per­sis­tence across page loads.

These are in­jected server-side by Cloudflare’s edge. They ex­ist only if the re­quest passed through Cloudflare’s net­work. A bot mak­ing di­rect re­quests to the ori­gin server or run­ning be­hind a non-Cloud­flare proxy will pro­duce miss­ing or in­con­sis­tent val­ues.

This is the part that mat­ters. __reactRouterContext is an in­ter­nal data struc­ture that React Router v6+ at­taches to the DOM. load­er­Data con­tains the route loader re­sults. client­Boot­strap is spe­cific to ChatGPT’s SSR hy­dra­tion.

These prop­er­ties only ex­ist if the ChatGPT React ap­pli­ca­tion has fully ren­dered and hy­drated. A head­less browser that loads the HTML but does­n’t ex­e­cute the JavaScript bun­dle won’t have them. A bot frame­work that stubs out browser APIs but does­n’t ac­tu­ally run React won’t have them.

This is bot de­tec­tion at the ap­pli­ca­tion layer, not the browser layer.

After col­lect­ing all 55 prop­er­ties, the pro­gram hits a 116-byte en­crypted blob that de­crypts to 4 fi­nal in­struc­tions:

[96.05, 3.99, 3.99], // JSON.stringify(fingerprint)

[22.58, 46.15, 57.34], // store

[33.34, 3.99, 74.43], // XOR(json, key)

[1.51, 56.88, 3.99] // RESOLVE → be­comes the to­ken

The fin­ger­print is JSON.stringify’d, XOR’d, and re­solved back to the par­ent. The re­sult is the OpenAI-Sentinel-Turnstile-Token header sent with every con­ver­sa­tion re­quest.

Turnstile is one of three chal­lenges. The other two:

Signal Orchestrator (271 in­struc­tions): Installs event lis­ten­ers for key­down, point­er­move, click, scroll, paste, and wheel. Monitors 36 win­dow.__oai_­so_* prop­er­ties track­ing key­stroke tim­ing, mouse ve­loc­ity, scroll pat­terns, idle time, and paste events. A be­hav­ioral bio­met­ric layer run­ning un­der­neath the fin­ger­print.

Proof of Work (25-field fin­ger­print + SHA-256 hash­cash): Difficulty is uni­form ran­dom (400K-500K), 72% solve un­der 5ms. Includes 7 bi­nary de­tec­tion flags (ai, cre­atePRNG, cache, solana, dump, InstallTrigger, data), all zero across 100% of 100 sam­ples. The PoW adds com­pute cost but is not the real de­fense.

The XOR key for the in­ner pro­gram is a server-gen­er­ated float em­bed­ded in the byte­code. Whoever gen­er­ated the turn­stile.dx knows the key. The pri­vacy bound­ary be­tween the user and the sys­tem op­er­a­tor is a pol­icy de­ci­sion, not a cryp­to­graphic one.

The ob­fus­ca­tion serves real op­er­a­tional pur­poses: it hides the fin­ger­print check­list from sta­tic analy­sis, pre­vents the web­site op­er­a­tor (OpenAI) from read­ing raw fin­ger­print val­ues with­out re­verse-en­gi­neer­ing the byte­code, makes each to­ken unique to pre­vent re­play, and al­lows Cloudflare to change what the pro­gram checks with­out any­one notic­ing.

But the “encryption” is XOR with a key that’s in the same data stream. It pre­vents ca­sual in­spec­tion. It does not pre­vent analy­sis.

No sys­tems were ac­cessed with­out au­tho­riza­tion. No in­di­vid­ual user data is dis­closed. All traf­fic was ob­served from con­sented par­tic­i­pants. The Sentinel SDK was beau­ti­fied and man­u­ally de­ob­fus­cated. All de­cryp­tion was per­formed of­fline us­ing Python.

Your brain is still grow­ing new cells right now. Here’s how to keep it hap­pen­ing

Say No to Palantir in Europe

To European gov­ern­ments and the EU

Review and phase out ex­ist­ing con­tracts with the com­pany.

And we call on the EU to ur­gently in­ves­ti­gate Palantir’s use across Europe, en­sure full trans­parency over con­tracts and data use, and push gov­ern­ments to halt new deals un­til strong safe­guards and de­mo­c­ra­tic over­sight are guar­an­teed.

Europe must not hand its pub­lic sys­tems, data, and se­cu­rity to a pri­vate US sur­veil­lance com­pany, es­pe­cially one that is in­volved in fu­el­ing wars and mass de­por­ta­tions.

Why is this im­por­tant?

A pow­er­ful com­pany en­ables geno­cide in Gaza, helps ICE sep­a­rate fam­i­lies, and fu­els Trump’s war with Iran. [1]

Most peo­ple have never even heard of it.

But gov­ern­ments across Europe are qui­etly sign­ing con­tracts with it, paid for with our tax money. [2] Its name is Palantir.

From the UK to Germany to France and be­yond, gov­ern­ments are hand­ing this US spy-tech gi­ant ac­cess to sen­si­tive pub­lic sys­tems and data. Police in Germany use it to track sus­pects, the UK hands it vast health­care datasets - and this is just the be­gin­ning. [3]

Palantir’s in­flu­ence in Europe is spread­ing fast, largely out of pub­lic sight.

That’s ex­actly why we must shine a light on it. Otherwise, we risk ex­pand­ing mass sur­veil­lance and fu­elling wars, while Europe hands its data and se­cu­rity to a US spy-tech gi­ant.

If we build mo­men­tum to ex­pose Palantir, we can push lead­ers to stop sign­ing new con­tracts and pro­tect Europe’s pub­lic sys­tems from pow­er­ful sur­veil­lance gi­ants.

Add your name now to de­mand trans­parency and stop the ex­pan­sion of Palantir in Europe.

And the peo­ple run­ning the com­pany aren’t hid­ing their in­ten­tions. CEO Alex Karp once said Palantir is “here to… scare en­e­mies and, on oc­ca­sion, kill them.” https://​www.wired.com/​story/​un­canny-val­ley-pod­cast-palan­tir-most-mys­te­ri­ous-com­pany-sil­i­con-val­ley

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leav­ing this box unchecked won’t re­move you.)

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By en­ter­ing your in­for­ma­tion you con­firm that you are at least 16 years old.

WeMove Europe is fight­ing for a bet­ter world, and we need he­roes like you to join our com­mu­nity of more than 700,000 peo­ple. Already you’re pow­er­ing this cam­paign call, but by click­ing “Yes”, you’ll re­ceive a wider range of cam­paigns that need your help. Sign up to hear more and make a real dif­fer­ence. If legally re­quired in your coun­try, we will send you an email to con­firm adding your data on our list.

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This is some­what of a ex­per­i­ment, think­ing is still free, so let’s in­dulge.

No per­mis­sion was needed, no sub­scrip­tion. No gate­keeper, and no mid­dle­man tak­ing its toll, be­tween me and the fu­ture me.

Just idea, code ed­i­tor, mu­sic in my ears and off I went to­wards a brighter fu­ture - a prod­uct mar­ket fit, or a learn­ing ex­pe­ri­ence.

Sharing was cool. Source code on GitHub. Talking to peers on fo­rums. MVPs to users. Oddball ideas on blogs. We did our think­ing in pub­lic be­cause of two as­sump­tions:

Ideas are cheap - ex­e­cu­tion is hard -and- the world ahead is ripe with op­por­tu­nity.

Did you get to read the Liu Cixin’s sec­ond 3-body-problem novel? - The Dark Forest. Well some of you did …

In it, the uni­verse is­n’t empty, it’s just silent. Because it’s a dan­ger­ous place. Every sur­viv­ing civ­i­liza­tion that re­veals it­self gets an­ni­hi­lated. So they all hide.

Annihilation is­n’t even malev­o­lent, but only the most ra­tio­nal game-the­o­retic re­ac­tion to be­com­ing aware of an­other civil­i­sa­tion.

It is also asym­met­ric. If you an­nounce your pres­ence, even if 4 out of 5 civs that no­tice you don’t an­ni­hi­late you im­me­di­ately (but they prob­a­bly should), the fifth might. It’s just a prob­a­bil­ity game, with per­madeath.

So hid­ing is the most ra­tio­nal - the only - strat­egy of sur­vival.

The ear­lier in­ter­net was­n’t like that. On the con­trary, the risk was be­ing silent, dis­con­nected, node with­out edges. Connecting im­proved your odds of suc­cess, be­com­ing a hub lifted you to an­other level.

Announcing, sig­nal­ing your ideas of­fered much greater ben­e­fit than risk, be­cause your value mul­ti­plied by con­nec­tions, and ex­e­cu­tion was the moat you could stand be­hind.

I said suc­cess above. Bright fu­ture and op­por­tu­nity makes you op­ti­mize for suc­cess. But, cur­rent year 2026, the in­ter­net, by a large mar­gin got con­sol­i­dated. By cor­po­ra­tions try­ing to ex­tract your info to ba­si­cally ad­ver­tise you, and gov­ern­ments try­ing to kill your pri­vacy to con­trol you.

Consolidated op­por­tu­nity space and bleaker fu­ture make us scram­ble for sur­vival. And when we play for sur­vival, we al­ready lost, the re­sult is known, we are just play­ing to post­pone it.

We de­vel­op­ers knew bet­ter, it was overblown. It still is, but some code gets gen­er­ated, and some code works, it’s a prob­a­bil­ity game, even­tu­ally prob­a­bil­ity rose to the level of “good enough”.

If whole pro­jects can get one-prompted or agent-teamed it be­comes just the money game.

You are cre­at­ing your cool stream­ing plat­form in your bed­room. Nobody is stop­ping you, but if you suc­ceed, if you get the sig­nal out, if you are be­ing no­ticed, the large plat­form with loads of cash can in­cor­po­rate your spe­cific in­no­va­tions sim­ply by throw­ing com­pute and cap­i­tal at the prob­lem. They can gen­er­ate a vari­a­tion of your in­no­va­tion every few days, even­tu­ally they will be able to ab­sorb your unique­ness. It’s just cash, and they have more of it than you.

So the safest bet again is to stay silent, or at least un­der the radar. Best bet is to not dis­rupt - suc­ceed at all … ?

But also, for­get about in­cum­bents with cap­i­tal.

You use prompts to gen­er­ate code, you use them to ex­plore ideas, to brain­storm, you use it in­stead of every­day search. And every prompt flows through cen­tral­ized AI plat­form. Every prompt is a sig­nal - re­veals in­tent.

The plat­form does­n’t need to read your prompt. It does­n’t spy on you specif­i­cally. It is­n’t sur­veil­lance. It’s just sta­tis­tics.

It’s a gra­di­ent in idea space. A de­mand curve made of hu­man in­ter­ests. The plat­form does­n’t need to bother with in­di­vid­ual prompts - it just needs to see where the ques­tions clus­ter. A map of where the world is mov­ing. And you are just in­put data.

The plat­form will know your idea is preg­nant far be­fore you will.

Two things changed: the web (or even our fu­ture) got con­sol­i­dated, and now with AIs, ex­e­cu­tion got cheap.

Before LLMs, a com­pany could­n’t just ab­sorb your idea and ship it. Ideas needed pro­gram­mers, and pro­gram­mers worked in meat-space-and-time, i.e. they were a lim­ited re­source, ex­pen­sive and slow, and most im­por­tantly: meat does­n’t scale.

Now the gap shrinks. The big cor­pos that help you be more ef­fi­cient pro­gram­mers - and whose sub­scrip­tions you pay - al­ready own:

If the dif­fi­culty and cost of build­ing are still there, they are on your end. That’s when the for­est gets dark.

The orig­i­nal Dark Forest as­sumes civ­i­liza­tions hide from hunters - other civ­i­liza­tions that might de­stroy them. But in the cog­ni­tive dark for­est, the most dan­ger­ous ac­tor is not your peer. It’s the for­est it­self.

We will again build and in­no­vate in pri­vate, hide, not share knowl­edge, mis­takes, ideas.

The vi­brant pub­lic ecosys­tem that cre­ated all the in­no­va­tion and moved it around the world will de­cline - the fo­rums, the blogs, the “here’s how I built this” will move to lo­cal, pri­vate spaces.

The para­dox: AI com­pa­nies needed hu­man open­ness to build their mod­els, but will also kill the open­ness be­cause the re­la­tion­ship is one-sided.

But in re­act­ing to this, the hu­man knowl­edge and in­no­va­tion will suf­fer too.

But we can al­ways out­in­no­vate the for­est.

Except, this is ex­actly what the for­est needs. The for­est needs your in­no­va­tion, be­cause your in­no­va­tion be­comes the in­no­va­tion of the for­est.

You think of some­thing new and ex­press it - through a prompt, through code, through a prod­uct - it en­ters the sys­tem. Your novel idea be­comes train­ing data. The sheer act of think­ing out­side the box makes the box big­ger.

This is the true hor­ror of the cog­ni­tive dark for­est: it does­n’t kill you. It lets you live and feeds on you. Your in­no­va­tion be­comes its ca­pa­bil­i­ties. Your dif­fer­en­ti­a­tion be­comes its me­dian.

Resistance is­n’t sup­pressed. It’s ab­sorbed. The very act of re­sist­ing feeds what you re­sist and makes it less frag­ile to fu­ture re­sis­tance.

You’ve just read this and this es­say is now in the for­est.

By de­scrib­ing the dy­namic, it be­came a part of it. The mod­els now know a lit­tle more about why we might hide.

I wrote this know­ing it feeds the thing I’m warn­ing you about. That’s not a con­tra­dic­tion. That’s the con­di­tion. You can’t step out­side the for­est to warn peo­ple about the for­est. There is no out­side.

The com­ments can be even more in­ter­est­ing and thought pro­vok­ing than the post:

Skip to con­tent

Secure your code as you build

We read every piece of feed­back, and take your in­put very se­ri­ously.

Include my email ad­dress so I can be con­tacted

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Note: On Windows “Server” you may need to in­stall vcrun­time140.dll.

If your sys­tem does not have the re­quired glibc ver­sion, try the (unsupported) builds for older glibc.

Run chmod u+x nvim-linux-x86_64.ap­pim­age && ./nvim-linux-x86_64.appimage

If your sys­tem does not have FUSE you can ex­tract the ap­pim­age:

./nvim-linux-x86_64.appimage –appimage-extract

./squashfs-root/usr/bin/nvim

Run chmod u+x nvim-linux-ar­m64.ap­pim­age && ./nvim-linux-arm64.appimage

If your sys­tem does not have FUSE you can ex­tract the ap­pim­age:

./nvim-linux-arm64.appimage –appimage-extract

./squashfs-root/usr/bin/nvim

You can’t per­form that ac­tion at this time.

Pure JavaScript/TypeScript li­brary for mul­ti­line text mea­sure­ment & lay­out. Fast, ac­cu­rate & sup­ports all the lan­guages you did­n’t even know about. Allows ren­der­ing to DOM, Canvas, SVG and soon, server-side.

Pretext side-steps the need for DOM mea­sure­ments (e.g. get­Bound­ing­Clien­tRect, off­setHeight), which trig­ger lay­out re­flow, one of the most ex­pen­sive op­er­a­tions in the browser. It im­ple­ments its own text mea­sure­ment logic, us­ing the browsers’ own font en­gine as ground truth (very AI-friendly it­er­a­tion method).

npm in­stall @chenglou/pretext

Clone the repo, run bun in­stall, then bun start, and open the /demos in your browser (no trail­ing slash. Bun de­vserver bugs on those) Alternatively, see them live at chen­glou.me/​pre­text. Some more at som­nai-dreams.github.io/​pre­text-demos

im­port { pre­pare, lay­out } from ‘@chenglou/pretext’

const pre­pared = pre­pare(‘AGI 春天到了. بدأت الرحلة 🚀’, ‘16px Inter’)

const { height, lineCount } = lay­out(pre­pared, tex­tWidth, 20) // pure arith­metics. No DOM lay­out & re­flow!

pre­pare() does the one-time work: nor­mal­ize white­space, seg­ment the text, ap­ply glue rules, mea­sure the seg­ments with can­vas, and re­turn an opaque han­dle. lay­out() is the cheap hot path af­ter that: pure arith­metic over cached widths. Do not re­run pre­pare() for the same text and con­figs; that’d de­feat its pre­com­pu­ta­tion. For ex­am­ple, on re­size, only re­run lay­out().

If you want textarea-like text where or­di­nary spaces, \t tabs, and \n hard breaks stay vis­i­ble, pass { white­Space: ‘pre-wrap’ } to pre­pare():

const pre­pared = pre­pare(texta­reaValue, ‘16px Inter’, { white­Space: ‘pre-wrap’ })

const { height } = lay­out(pre­pared, textareaW­idth, 20)

* pre­pare() is about 19ms for the shared 500-text batch

* lay­out() is about 0.09ms for that same batch

We sup­port all the lan­guages you can imag­ine, in­clud­ing emo­jis and mixed-bidi, and caters to spe­cific browser quirks

The re­turned height is the cru­cial last piece for un­lock­ing web UI’s:

* fancy user­land lay­outs: ma­sonry, JS-driven flexbox-like im­ple­men­ta­tions, nudg­ing a few lay­out val­ues with­out CSS hacks (imagine that), etc.

* de­vel­op­ment time ver­i­fi­ca­tion (especially now with AI) that la­bels on e.g. but­tons don’t over­flow to the next line, browser-free

* pre­vent lay­out shift when new text loads and you wanna re-an­chor the scroll po­si­tion

Switch out pre­pare with pre­pare­With­Seg­ments, then:

* lay­outWith­Lines() gives you all the lines at a fixed width:

im­port { pre­pare­With­Seg­ments, lay­outWith­Lines } from ‘@chenglou/pretext’

const pre­pared = pre­pare­With­Seg­ments(‘AGI 春天到了. بدأت الرحلة 🚀’, ’18px “Helvetica Neue”’)

const { lines } = lay­outWith­Lines(pre­pared, 320, 26) // 320px max width, 26px line height

for (let i = 0; i < lines.length; i++) ctx.fill­Text(lines[i].text, 0, i * 26)

* walk­Lin­eRanges() gives you line widths and cur­sors with­out build­ing the text strings:

let maxW = 0

walk­Lin­eRanges(pre­pared, 320, line => { if (line.width > maxW) maxW = line.width })

// maxW is now the widest line — the tight­est con­tainer width that still fits the text! This mul­ti­line “shrink wrap” has been miss­ing from web

* lay­out­NextLine() lets you route text one row at a time when width changes as you go:

let cur­sor = { seg­mentIn­dex: 0, graphe­meIn­dex: 0 }

let y = 0

// Flow text around a floated im­age: lines be­side the im­age are nar­rower

while (true) {

const width = y < im­age.bot­tom ? colum­n­Width - im­age.width : colum­n­Width

const line = lay­out­NextLine(pre­pared, cur­sor, width)

if (line === null) break

ctx.fill­Text(line.text, 0, y)

cur­sor = line.end

y += 26

This us­age al­lows ren­der­ing to can­vas, SVG, WebGL and (eventually) server-side.

pre­pare(text: string, font: string, op­tions?: { white­Space?: ‘normal’ | ‘pre-wrap’ }): PreparedText // one-time text analy­sis + mea­sure­ment pass, re­turns an opaque value to pass to `layout()`. Make sure `font` is synced with your css `font` de­c­la­ra­tion short­hand (e.g. size, weight, style, fam­ily) for the text you’re mea­sur­ing. `font` is the same for­mat as what you’d use for `myCanvasContext.font = …`, e.g. `16px Inter`.

lay­out(pre­pared: PreparedText, maxWidth: num­ber, line­Height: num­ber): { height: num­ber, lineCount: num­ber } // cal­cu­lates text height given a max width and line­Height. Make sure `lineHeight` is synced with your css `line-height` de­c­la­ra­tion for the text you’re mea­sur­ing.

pre­pare­With­Seg­ments(text: string, font: string, op­tions?: { white­Space?: ‘normal’ | ‘pre-wrap’ }): PreparedTextWithSegments // same as `prepare()`, but re­turns a richer struc­ture for man­ual line lay­outs needs

lay­outWith­Lines(pre­pared: PreparedTextWithSegments, maxWidth: num­ber, line­Height: num­ber): { height: num­ber, lineCount: num­ber, lines: LayoutLine[] } // high-level api for man­ual lay­out needs. Accepts a fixed max width for all lines. Similar to `layout()`’s re­turn, but ad­di­tion­ally re­turns the lines info

walk­Lin­eRanges(pre­pared: PreparedTextWithSegments, maxWidth: num­ber, on­Line: (line: LayoutLineRange) => void): num­ber // low-level api for man­ual lay­out needs. Accepts a fixed max width for all lines. Calls `onLine` once per line with its ac­tual cal­cu­lated line width and start/​end cur­sors, with­out build­ing line text strings. Very use­ful for cer­tain cases where you wanna spec­u­la­tively test a few width and height bound­aries (e.g. bi­nary search a nice width value by re­peat­edly call­ing walk­Lin­eRanges and check­ing the line count, and there­fore height, is “nice” too. You can have text mes­sages shrinkwrap and bal­anced text lay­out this way). After walk­Lin­eRanges calls, you’d call lay­outWith­Lines once, with your sat­is­fy­ing max width, to get the ac­tual lines info.

lay­out­NextLine(pre­pared: PreparedTextWithSegments, start: LayoutCursor, maxWidth: num­ber): LayoutLine | null // it­er­a­tor-like api for lay­ing out each line with a dif­fer­ent width! Returns the LayoutLine start­ing from `start`, or `null` when the para­graph’s ex­hausted. Pass the pre­vi­ous line’s `end` cur­sor as the next `start`.

type LayoutLine = {

text: string // Full text con­tent of this line, e.g. ‘hello world’

width: num­ber // Measured width of this line, e.g. 87.5

start: LayoutCursor // Inclusive start cur­sor in pre­pared seg­ments/​graphemes

end: LayoutCursor // Exclusive end cur­sor in pre­pared seg­ments/​graphemes

type LayoutLineRange = {

width: num­ber // Measured width of this line, e.g. 87.5

start: LayoutCursor // Inclusive start cur­sor in pre­pared seg­ments/​graphemes

end: LayoutCursor // Exclusive end cur­sor in pre­pared seg­ments/​graphemes

type LayoutCursor = {

seg­mentIn­dex: num­ber // Segment in­dex in pre­pare­With­Seg­ments’ pre­pared rich seg­ment stream

graphe­meIn­dex: num­ber // Grapheme in­dex within that seg­ment; `0` at seg­ment bound­aries

clearCache(): void // clears Pretext’s shared in­ter­nal caches used by pre­pare() and pre­pare­With­Seg­ments(). Useful if your app cy­cles through many dif­fer­ent fonts or text vari­ants and you want to re­lease the ac­cu­mu­lated cache

set­Lo­cale(lo­cale?: string): void // op­tional (by de­fault we use the cur­rent lo­cale). Sets lo­cale for fu­ture pre­pare() and pre­pare­With­Seg­ments(). Internally, it also calls clearCache(). Setting a new lo­cale does­n’t af­fect ex­ist­ing pre­pare() and pre­pare­With­Seg­ments() states (no mu­ta­tions to them)

Pretext does­n’t try to be a full font ren­der­ing en­gine (yet?). It cur­rently tar­gets the com­mon text setup:

* If you pass { white­Space: ‘pre-wrap’ }, or­di­nary spaces, \t tabs, and \n hard breaks are pre­served in­stead of col­lapsed. Tabs fol­low the de­fault browser-style tab-size: 8. The other wrap­ping de­faults stay the same: word-break: nor­mal, over­flow-wrap: break-word, and line-break: auto.

* sys­tem-ui is un­safe for lay­out() ac­cu­racy on ma­cOS. Use a named font.

* Because the de­fault tar­get in­cludes over­flow-wrap: break-word, very nar­row widths can still break in­side words, but only at grapheme bound­aries.

See DEVELOPMENT.md for the dev setup and com­mands.

Sebastian Markbage first planted the seed with text-lay­out last decade. His de­sign — can­vas mea­sure­Text for shap­ing, bidi from pdf.js, stream­ing line break­ing — in­formed the ar­chi­tec­ture we kept push­ing for­ward here.

Philly court­rooms are re­main­ing friendly to the Luddites. At least with eye­wear.

The Philadelphia court sys­tem is im­ple­ment­ing a ban on all forms of smart or AI-integrated eye­wear, the First Judicial District of Pennsylvania an­nounced this week.

The ban will go into ef­fect Monday.

From then on, any eye­wear with video and au­dio record­ing ca­pa­bil­ity will be for­bid­den in all of the First Judicial District build­ings, cour­t­houses, or of­fices, even for peo­ple who have a pre­scrip­tion. Other de­vices with record­ing ca­pa­bil­i­ties like cell phones and lap­tops con­tinue to be al­lowed in­side court­rooms but must be pow­ered off and stowed away.

“Since these glasses are dif­fi­cult to de­tect in court­rooms, it was de­ter­mined they should be banned from the build­ing,” said court spokesper­son Martin O’Rourke.

The ban is meant to pre­vent po­ten­tial wit­ness and ju­ror in­tim­i­da­tion from threats of record­ing, O’Rourke said. It is un­clear whether Philadelphia courts will im­ple­ment ex­tra screen­ing mea­sures to de­ter­mine if a per­son’s glasses vi­o­late the rule.

If some­one were caught at­tempt­ing to bring smart eye­wear into those spaces, they could be barred en­try or re­moved from the build­ing, and ar­rested and charged with crim­i­nal con­tempt, O’Rourke said. The only po­ten­tial ex­cep­tions would be if a judge or court lead­er­ship had granted prior writ­ten per­mis­sion to a smart glasses user.

Philadelphia is part of an early wave of court sys­tems that are im­ple­ment­ing smart eye­wear bans, join­ing sys­tems like those in Hawaii, Wisconsin, and North Carolina. While most courts al­ready ban any kind of record­ing de­vices in­side the court­rooms, it’s not yet com­mon to have ex­plicit bans on smart eye­wear or to com­pletely bar them from the build­ing.

Without di­rect bans in place, judges typ­i­cally have lat­i­tude to make rul­ings on what de­vices are al­lowed in­side their court room. During the re­cent trial in Los Angeles that found Google and Meta li­able for so­cial me­dia caus­ing harm, Meta CEO Mark Zuckerberg and his col­leagues wore their com­pa­ny’s smart eye­wear into the court­room. The judge in that case or­dered them to re­move the glasses, and threat­ened to hold any­one who had used them to record court pro­ceed­ings in con­tempt of court.

Google Glass was a fre­quent butt of the joke af­ter it was in­tro­duced over a decade ago, but rea­son­ably af­ford­able and avail­able smart glasses have fi­nally be­gun catch­ing on within the last year.

Eyewear gi­ants Ray-Ban and Oakley both now sell glasses in­te­grated with Meta AI and au­dio and vi­sual record­ing for less than $500. The new glasses were the fo­cuses of each com­pa­ny’s re­cent Super Bowl ad cam­paigns, and the com­pa­nies re­port­edly hawked 7 mil­lion pairs in 2025. They have a head start on Apple, which is plan­ning to join the mar­ket with its own smart glasses in 2027.

Almost 30 years af­ter the in­tri­cate web of nerves in­side the pe­nis was plot­ted out, the same map­ping has fi­nally been com­pleted for one of the least-stud­ied or­gans in the hu­man body — the cli­toris.

As well as re­veal­ing the ex­tent of the nerves that are cru­cial to or­gasms, the work shows that some of what medics are learn­ing about the anatomy of the cli­toris is wrong, and could help pre­vent women who have pelvic op­er­a­tions from end­ing up with poorer sex­ual func­tion.

The cli­toris, re­spon­si­ble for sex­ual plea­sure, is one of the least stud­ied or­gans of the hu­man body. Cultural taboo around fe­male sex­u­al­ity has held back sci­en­tific in­ves­ti­ga­tions and the cli­toris did not even make it into stan­dard anatomy text­books un­til the 20th cen­tury. And in the 38th edi­tion of Gray’s Anatomy in 1995 it was in­tro­duced as just “a small ver­sion of the pe­nis”.

A Melbourne urol­o­gist, Helen O’Connell, says the cli­toris has been ig­nored by re­searchers for far too long. “It has been deleted in­tel­lec­tu­ally by the med­ical and sci­en­tific com­mu­nity, pre­sum­ably align­ing at­ti­tude to a so­ci­etal ig­no­rance,” she said.

To get a bet­ter idea of the in­ner work­ings of this key plea­sure-re­lated or­gan, Ju Young Lee, a re­search as­so­ci­ate at Amsterdam University Medical Center in the Netherlands, and her col­leagues used high-en­ergy X-rays to cre­ate 3D scans of two fe­male pelvises that had been do­nated through a body donor or­gan pro­gramme.

The scans re­vealed in 3D the tra­jec­tory of the five com­plex tree-like branch­ing nerves run­ning through the cli­toris in un­prece­dented de­tail, the widest 0.7mm across. The work has been re­ported on the preprint server bioRxiv and has not yet been peer re­viewed.

“This is the first ever 3D map of the nerves within the glans of the cli­toris,” said Lee. She is amazed it has taken so long, con­sid­er­ing a sim­i­lar level of knowl­edge re­gard­ing the pe­nile glans was reached back in 1998, 28 years ago.

Lee and her col­leagues show that some branches of cli­toral nerves reach the mons pu­bis, the rounded mound of tis­sue over the pu­bic bone. Others go to the cli­toral hood, which sits over the small, sen­si­tive, ex­ter­nal part of the cli­toris — the glans cli­toris — which is just 10% of the to­tal or­gan. Other nerves reach the folds of skin of the vulva, the labial struc­tures.

Previous re­search had in­di­cated that the big dor­sal nerve of the cli­toris grad­u­ally di­min­ished as it ap­proached the glans. However, the new scans ap­pear to show that some of what medics have been learn­ing in anatomy is wrong and the nerve con­tin­ues strongly all the way to the end.

“I was es­pe­cially fas­ci­nated by the high-res­o­lu­tion im­ages within the glans, the most sen­si­tive part of the cli­toris, as these ter­mi­nal nerve branches are im­pos­si­ble to see dur­ing dis­sec­tion,” said Georga Longhurst, the head of anatom­i­cal sci­ences at St George’s, University of London.

O’Connell, who pub­lished the first com­pre­hen­sive anatom­i­cal study of the cli­toris in 1998, said the find­ings were cru­cial to un­der­stand­ing the fe­male sen­sory mech­a­nism un­der­ly­ing arousal and or­gasm via stim­u­lat­ing the cli­toris. “Orgasm is a brain func­tion that leads to im­proved health and well­be­ing as well as hav­ing pos­i­tive im­pli­ca­tions for hu­man re­la­tion­ships and pos­si­bly fer­til­ity,” she said.

The map­ping of cli­toral nerves is likely to in­form re­con­struc­tive surgery af­ter fe­male gen­i­tal mu­ti­la­tion, one of the most ex­treme ex­am­ples of cul­tural misog­yny. According to the World Health Organization, more than 230 mil­lion girls and women alive to­day in 30 coun­tries in Africa, the Middle East and Asia have un­der­gone such mu­ti­la­tion, in which the vis­i­ble part of the cli­toris may be re­moved, along with parts of the labia.

The prac­tice has no health ben­e­fits and can re­sult in is­sues in­clud­ing se­vere bleed­ing, in­fec­tion, prob­lems uri­nat­ing, men­strual dif­fi­cul­ties and com­pli­ca­tions in child­birth.

About 22% of women who un­dergo sur­gi­cal re­con­struc­tion af­ter mu­ti­la­tion ex­pe­ri­ence a de­cline in or­gas­mic ex­pe­ri­ence af­ter their op­er­a­tion, so a bet­ter un­der­stand­ing of how far the nerves ex­tend could re­duce that per­cent­age, said Lee.

O’Connell said the work could also in­form surgery to treat vul­var can­cer, gen­der re­as­sign­ment surgery and gen­i­tal cos­metic surg­eries, such as labi­aplasty, which in­creased in pop­u­lar­ity by 70% from 2015 to 2020.

Lee is hop­ing to open a cli­toris ex­hi­bi­tion within Amsterdam University Medical Center to help ex­pand knowl­edge about the cli­toris, in­spired by the Vagina Museum in London.

The right ar­row key on my Macbook Pro key­board stopped work­ing the other day.

I say “stopped work­ing”, but tech­ni­cally it works too well now, it is be­ing pressed con­stantly, which makes the lap­top pretty un­us­able.

After get­ting over the ini­tial frus­tra­tion of be­ing the owner of a bro­ken de­vice, I cleaned it. Took the key­cap off, used a blower, a brush and even al­co­hol.

Next, I went down the route of try­ing to fig­ure out how to re­pair the thing. In my naivety I thought, this should be sim­ple, or­der a re­place­ment key­board, take the lap­top apart, re­place the key­board and good to go. But no.

Apple has de­cided that the part the users in­ter­act with the most should be the hard­est to re­place. They do this by riv­et­ing the en­tire key­board as­sem­bly to the top case. Meaning you can’t just re­place the key­board, you have to re­place the en­tire top case. A re­place­ment key­board was around €50, a top case re­place­ment part is around €730. This is like 1/5 of the price of my en­tire lap­top. And only if I want to try to do the re­pair my­self. So add an­other €100 to pay an au­tho­rized re­pair shop to do it.

After think­ing about it for a bit I de­cided to remap all the ar­row keys us­ing

Karabiner Elements

. I dis­abled the right ar­row key and mapped cap­slock + J K L I. And do­nated $10 to the pro­ject. A small price to pay to post­pone a very ex­pen­sive re­pair bill.

Sometimes you have to feel the hurt on your own body to fully un­der­stand the ab­sur­dity of the world, and I felt the hurt on hard­ware re­pairabil­ity this week. Hopefully when this lap­top fully dies I’ll re­mem­ber this ex­pe­ri­ence and choose to buy a more re­pairable lap­top like a ThinkPad or a Framework lap­top.

Here’s hop­ing gov­ern­ments reg­u­late lap­top man­u­fac­tur­ers to ac­tu­ally make re­pairable ma­chines in the fu­ture.

UPDATE: There’s some great dis­cus­sion in the

Hackernews Comments.

Multiple peo­ple have posted videos and guides on how to do the re­pair your­self:

If you’re in a sim­u­lar sit­u­a­tion like me, these could save you a lot of money!