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Brad Fitzpatrick

@bradfitz.com
11K followers 330 following 998 posts

I do computers. Married to @radkat.fitzpat.com. Three kids. Xoogler. Go (#golang) team 2010~2020. Made LiveJournal, OpenID, memcached. Currently at @Tailscale.com making WireGuard easy. Seattle, WA // Bainbridge

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Reposted by Brad Fitzpatrick
Damien Miller @damienmiller.bsky.social · 16h
Anthropic may not have intended to write an excellent ad for GLM 5.3, but that's what they did. www.anthropic.com/research/glm... Unlike Mythos, I might actually have a chance at using GLM for defensive research. Anthropic didn't reply to any of my requests for Mythos access for use on OpenSSH.
anthropic.com
GLM-5.3 and the spread of advanced cyber capabilities
GLM-5.3 can autonomously build end-to-end cyber exploits, but unlike other frontier models, it was released without meaningful safeguards to limit misuse.
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Reposted by Brad Fitzpatrick
Tailcat @tailcat.dev · 18/09/2026
Oh, hi. 👋 We might announce Tailcat releases here and reskeet tailcat-related stuff! Holler if you have questions.
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Brad Fitzpatrick @bradfitz.com · 14/09/2026
At a kid's birthday party and I perked up hearing the host behind me say "and margarita, help yourself!" I spun around and saw that the pizzas had arrived... Margherita.
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Brad Fitzpatrick @bradfitz.com · 07/09/2026
sync, runtime, cmd/compile: add way to mix Mutex/chan in select go-review.googlesource.com/c/go/+/82854... This is like the 5th time I've thrown this at a new AI model but GPT-6-Astra seems to have maybe done it? After it first rejected me for cybersecurity reasons but I talked it out of it #golang
go-review.googlesource.com
Gerrit Code Review
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Brad Fitzpatrick @bradfitz.com · 06/09/2026
My first time trying to use GPT-6-Astra and it denies me for cybersecurity reasons. For trying to optimize something in the Go runtime. Sigh. So dumb.
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Brad Fitzpatrick @bradfitz.com · 05/09/2026
Writing code for you is cool and all, but my favorite use of AI is passionately swearing and ranting at my computer about something and then adding "Now write that up nicely and politically" 💩
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Brad Fitzpatrick @bradfitz.com · 28/08/2026
We unfortunately learned that Go staticcheck and Go 1.27 generic methods aren't playing well together at the moment: github.com/golang/go/is... It doesn't seem like it's staticcheck's fault, though. #golang
github.com
go/types: staticcheck started crashing on us with Go 1.27 generic methods · Issue #81188 · golang/go
We just started converting Tailscale's internal codebase to use Go 1.27's generic methods and a few rounds of conversion went well, and then we hit CI failures with staticcheck crashing on us: pani...
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Brad Fitzpatrick @bradfitz.com · 26/08/2026
I can finally talk about this, 3 years later... github.com/tailscale/ta... It's a library + CLI tool that's like netcat, but over Tailscale's data plane without any control plane (no accounts, no dependence on Tailscale the company, all open source) WireGuard + NAT traversal without IP addresses.
github.com
GitHub - tailscale/tailcat: like netcat, but over Tailscale's data plane, without Tailscale's control plane
like netcat, but over Tailscale's data plane, without Tailscale's control plane - tailscale/tailcat
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Brad Fitzpatrick @bradfitz.com · 17/08/2026
Humanity has mastered automatic water faucets and made some good swings at automatic hand driers. I wonder if AI can help the humans figure out how to make the elusive automatic soap dispensers that never seem to work. (deep thought brought to you from 6 hours at LHR from a very delayed flight 😭)
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Brad Fitzpatrick @bradfitz.com · 13/08/2026
On 2024-02-22 I reached out to @antithesis.com fanboying and wanting to use it for @tailscale.com. They were expensive & I couldn’t get people on board w/ buying their service. Instead, more time + money went to: tailscale.com/blog/sqlite-... Nerd sniped them and: antithesis.com/blog/2026/wa... 😅
antithesis.com
Breaking the WAL | Antithesis
I did this from a lawn chair on the Sunshine Coast.
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Brad Fitzpatrick @bradfitz.com · 12/08/2026
Just saw my first solar eclipse. A++. Would recommend. (Currently on Liberty of the Seas, just north of Spain) Here it is at 4x rate:
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Brad Fitzpatrick @bradfitz.com · 09/08/2026
“He doesn’t know how to use the three seashells!” (Me trying to figure out the unlabeled bins in Bilbao 😅)
Four bins saying only "B", all of different color
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Brad Fitzpatrick @bradfitz.com · 09/08/2026
🎵 "You take your car to work I'll take my board And when you're out of fuel I'm still afloat..." 🎵
Place for bikes and surfboards on the metro
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Brad Fitzpatrick @bradfitz.com · 08/08/2026
brb wardriving Liberty of the Seas to build a shipwide geolocation app from the bazillion wifi APs Luckily I have an Android with me to scan (better scan APIs). Then can use data from iOS which only reports the currently connect AP MAC or whatever 2 decks down, 13 to go? 😅
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Brad Fitzpatrick @bradfitz.com · 24/07/2026
I'm losing my patience with GitHub. Both the constant outages and constant lying piss me off.
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Brad Fitzpatrick @bradfitz.com · 20/07/2026
Me: yo, analyze why this package's tests are slow Fable: "zomg Accepted Use Policy violation!!!" 🙄
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Brad Fitzpatrick @bradfitz.com · 04/07/2026
4th of July Fun Run 5K! 🎉🇺🇸 First organized run in ages. Fun indeed. And earns me 3.1 beers in my 2026 mile-per-beer (any alcoholic drink) resolution! I'm trying to work up to a half marathon again. Longest run lately is 6.5 miles.
Map. 26m10s.
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Brad Fitzpatrick @bradfitz.com · 03/07/2026
I tried to delete some files from a USB stick on macOS. macOS: "This operation cannot be completed because the disk is full." 🏆
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Brad Fitzpatrick @bradfitz.com · 23/06/2026
Hey @goodtogo.wsdot.wa.gov, a unique merchant-locked credit card number (from Privacy.com) I've only ever given to you guys tried to buy $2,200 of sandwiches. Did you get compromised? I closed the card and see no other activity on it, at least.
Privacy decline notification saying my GoodToGo card was declined at Jersey Mike's Online UC for $2,200 for going over the card limit.
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Brad Fitzpatrick @bradfitz.com · 22/06/2026
3yo cut off a bunch of her hair w/ scissors, painted her whole face like war paint, skipped her nap, refuses to take off her bike helmet, wants a snack but isn't she what, kinda fell asleep on one bike ride but wants another bike ride now, refuses to take a bath (still w/ helmet + face paint) HFD!
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Brad Fitzpatrick @bradfitz.com · 14/06/2026
3yo: "papa, (can) you carry me?" "On my shoulders?" "No! On your belly!" 🔥
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Brad Fitzpatrick @bradfitz.com · 31/05/2026
Our 3yo is loving this Mariners game. “We’ll sell you the whole seat but you’ll only need the bed”
T-Mobile parkSleeping baby on me
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Brad Fitzpatrick @bradfitz.com · 28/05/2026
10 year anniversary with @radkat.fitzpat.com! 😘
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Brad Fitzpatrick @bradfitz.com · 19/05/2026
Every year or so (for the past ~9yr) I check whether Google Fi lets me have an Apple Watch yet, and every year I find out the answer is no and don't buy an Apple Watch. But it'd be nice for running. But I also don't want to change carriers. Google Fi has just been so pleasantly non-shitty. Sigh.
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Reposted by Brad Fitzpatrick
Hello, it's Dan McDaid @danmcdaid.bsky.social · 16/05/2026
Got a notification from a medieval copyright lawyer
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Brad Fitzpatrick @bradfitz.com · 16/05/2026
This little thingy is great: pockethernet.com (Not an ad. No affiliate links. Just enamored.)
Pocket-size hand-held device with an ethernet cable plugged inscreenshot of app showing wiremapscreenshot of app showing other stuff it does: TDR, PoE, Link, IPv4/v6, ping, ...
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Brad Fitzpatrick @bradfitz.com · 14/05/2026
"Racksberry Pi" My new rack to eventually better organize/cable my collection of all Raspberries Pi, mips, mipsle, mips64, riscv64, etc rando hardware. Still setting it up. Only silent fanless stuff is allowed here. Servers with fans/IPMI go in the garage where they can be loud and not needy.
new half rack of Raspberry Pis and other weirdo little fanless SBCs for testing
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Brad Fitzpatrick @bradfitz.com · 30/04/2026
Long shot, but reposting by request of wife. 😅 Or--- other CrunchLabs-inspired birthday party ideas? (hah, in Seattle ideally... :))
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Reposted by Brad Fitzpatrick
Brad Fitzpatrick @bradfitz.com · 24/04/2026
And while I was doing operating systems whose names match /^R.*OS$/ .... Tailscale on ReactOS! (reactos.org) It's like an open source Windows XP. Go toolchain + std require Win10+, and ReactOS is pre-Win7, so Go needed changes. Then ran a tsnet server on it, serving its own screenshot:
Screenshot of browser hitting a tsnet server with an HTML page showing a screenshot of a ReactOS desktop running said tsnet-demo.exe
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Reposted by Brad Fitzpatrick
Brad Fitzpatrick @bradfitz.com · 24/04/2026
Another one for Tailscale Hack Week: I got Go ported to Redox OS (www.redox-os.org), enough to run Tailscale inside it. i.e. GOOS=redox GOARCH=amd64 Go std tests exposed a Redox libc bug with unsafe Rust, too. And a kernel crash.
Screenshot of QEMU running RedoxOS, with a terminal showing log output of Tailscale running on it, and a browser showing connecting to it, "Go redox/amd64", etc
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Brad Fitzpatrick @bradfitz.com · 23/04/2026
Uhhh... "Claude Code is unable to respond to this request, which appears to violate our Usage Policy" ... "This request triggered restrictions on violative cyber content and was blocked under Anthropic's Usage Policy." dude, I'm writing networking code + tunnels + proxies. sorry if bad guys do too
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Brad Fitzpatrick @bradfitz.com · 23/04/2026
Tailscale on UEFI ... who needs an OS, really? (using github.com/usbarmory/ta...) And yes, clearly putting a bootloader in here is an obvious next step 😉 This week is Hack Week at Tailscale. This is one of the 4 weird new places I got Tailscale running. #golang #tamago #tailscale #hackweek
Laptop showing Tailscale logo, "Tailscale on UEFI, state : NeedsLogin" and a QR code
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Reposted by Brad Fitzpatrick
nrc @ncameron.org · 21/04/2026
🎉🎉 I've been working with the folk at Tailscale on their new #rust-lang library. Last week it was officially announced (tailscale.com/blog/tailsca...) along with open-sourcing the code (github.com/tailscale/ta...).
tailscale.com
An early look at tailscale-rs, a tsnet library in Rust
We've launched an experimental Rust library for Tailscale via tsnet. Help test tailscale-rs and shape it with your feedback.
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Brad Fitzpatrick @bradfitz.com · 19/04/2026
Kids: "cereal?!? Why does it say USB Cereal?" (They're playing with a Crunchlabs Hack Packet IR Turret flashing different code to its microcontroller... 🤘)
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Brad Fitzpatrick @bradfitz.com · 16/04/2026
Perl bindings for Tailscale's nascent Rust implementation... 🐪 metacpan.org/pod/Tailscale Little 14 year gap in my CPAN uploads there, whoops... 🤪 www.cpan.org/authors/id/B... Depends on 4 pending PRs to github.com/tailscale/ta...
metacpan.org
Tailscale
Perl bindings for tailscale-rs
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Brad Fitzpatrick @bradfitz.com · 14/04/2026
Me, naked at my regular skin check, looking for sketchy moles: Her: "so, you have a pretty famous name in the world of dermatology..." Me: "oh, I know! Let me tell you all about Unicode encoding and emoji modifiers!!"
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Brad Fitzpatrick @bradfitz.com · 10/04/2026
Somebody was talking about early Google code review systems & I was curious to find my old patches. Some old Guido commit messages: "The last set of speedups suggested by the inimitable, incorrigible, mysterious Brad F" ... "Another trick from the hat of Brad F" 🤣 github.com/rietveld-cod... etc
github.com
Issue 2992: Avoid querying for draft counts on issues without drafts. · rietveld-codereview/rietveld@ae4e498
The last set of speedups suggested by the inimitable, incorrigible, mysterious Brad F.
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Brad Fitzpatrick @bradfitz.com · 09/04/2026
Tailscale has recently "found" two SQLite corruption bugs, now both fixed upstream in sqlite.org/releaselog/3... The first: sqlite.org/wal.html#wal... The second: sqlite.org/staleexpridx... Fun times holding SQLite in unique ways! SQLite folk have been a joy to work with & worth every penny.
sqlite.org
SQLite Release 3.53.0 On 2026-04-09
A complete list of SQLite releases in a single page and a chronology are both also available. A detailed history of every check-in is available at SQLite version control site.
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Brad Fitzpatrick @bradfitz.com · 28/03/2026
At #AtmosphereConf in Vancouver BC (atmosphereconf.org). It's nice seeing a bunch of familiar faces!
atmosphereconf.org
ATmosphereConf 2026
ATmosphereConf is the global atproto community conference. Join us in Vancouver, Canada, March 26th - 29th, 2026.
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Brad Fitzpatrick @bradfitz.com · 25/03/2026
Apparently somebody just built us a new marketing site... 🙏 justfuckingusetailscale.com
JUST FUCKING USE
TAILSCALE
STOP FUCKING AROUND. CONNECT ANYWHERE.

(with AI slop image of big explosions and laptops and phones and routers and such)
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Brad Fitzpatrick @bradfitz.com · 23/03/2026
graffiti ad for dry cleaning place: "Can AI do Laundry & Dry Cleaning?" "No, but we can!"
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Brad Fitzpatrick @bradfitz.com · 21/03/2026
Rick & Morty robot purpose pass the butter meme, but with the robot being Claude Code and doing menial work of resolving git merge conflicts
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Brad Fitzpatrick @bradfitz.com · 10/03/2026
I programmed in BASIC when ~6yo. Then we got Turbo C and my dad explained high-level vs low-level languages. With Turbo C I could read the mouse! I'd asked if there was a language where I could just "make an elephant walk across the screen". He said ~"naah, sorry, not that high" But there is now!
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Brad Fitzpatrick @bradfitz.com · 08/03/2026
Me: "so how old are your kids?” Random mom from park: “3, 6, 9” Me: “damn you fine” The mom: <stares at me> Me: (oh no) Mom: “ha, I had almost forgotten that song!" Me: (phew)
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Brad Fitzpatrick @bradfitz.com · 06/03/2026
SQLite PSA sqlite.org/releaselog/3... sqlite.org/wal.html#wal...
sqlite.org
SQLite Release 3.52.0 On 2026-03-06
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Brad Fitzpatrick @bradfitz.com · 05/03/2026
Before I went to bed, asked Claude to make FreeBSD work in CI. Woke up to "then binary-patches the kernel to fix a TSC initialization panic on Intel CPUs. The upstream kernel only handles AMD under Firecracker; the patch changes one byte to redirect a tsc_disabled = 1 assignment to tsc_freq = 1.."🤯
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Brad Fitzpatrick @bradfitz.com · 03/03/2026
"So I Got That Goin For Me Which Is Nice Meme" starting with "I helped Claude when it got stuck and it told me I was clever"
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Brad Fitzpatrick @bradfitz.com · 02/03/2026
The nearly-3yo hasn't pooped in her diaper for a few weeks now 🤞 She even silently goes off on her own to poop unprompted and then yells out at us "CHECK IT OUT!" from the bathroom so then we all have to go check it out and celebrate. (Minor thing to be optimistic about.)
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Brad Fitzpatrick @bradfitz.com · 23/02/2026
Claude code: "get in loser, we're going coding"
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Brad Fitzpatrick @bradfitz.com · 16/02/2026
"Microchip technology in every towel!"
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