Joined December 2008
108 Photos and videos
Sebastien Pahl retweeted
spent the evening building a cardputer client for codex can send tasks, watch edits come in, approve changes cardputer → cloudflare sandbox → codex kinda ridiculous, I know
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Sebastien Pahl retweeted
May 20
Today, we share a breakthrough on the planar unit distance problem, a famous open question first posed by Paul Erdős in 1946. For nearly 80 years, mathematicians believed the best possible solutions looked roughly like square grids. An OpenAI model has now disproved that belief, discovering an entirely new family of constructions that performs better. This marks the first time AI has autonomously solved a prominent open problem central to a field of mathematics.
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Sebastien Pahl retweeted
Excited to launch Claude Managed Agents on Cloudflare today! - Run sandboxes as microVMs or even lighter-weight isolates on CF - Zero-trust creds injection, custom egress proxies, better observability, private services via VPC - Agent Email Browser Run easy custom tool calls
May 19
Live from Code with Claude London: we're launching self-hosted sandboxes (public beta) and MCP tunnels (research preview) in Claude Managed Agents. Run agents inside your own perimeter, with your security controls applied by default.
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Sebastien Pahl retweeted
you can build a Python agent that accepts a coding task, executes it inside a Cloudflare Sandbox, and copies the output files to your local machine @OpenAIDevs x @CloudflareDev Check out our guide here: developers.cloudflare.com/sa…
Build long-running agents with more control over agent execution. New capabilities in the Agents SDK: • Run agents in controlled sandboxes • Inspect and customize the open-source harness • Control when memories are created and where they’re stored
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Sebastien Pahl retweeted
One point of confusion I'm seeing: Lots of people assume you're supposed to run the AI agent harness itself inside a sandbox, and wonder how to do that with Dynamic Workers. The harness does *not* need to be in the sandbox. It can be a regular old Worker (probably a Durable Object, probably using Cloudflare Agents SDK[0]). Remember that an LLM can't manipulate the world at all unless you give it tools. So if you are careful about what tools you give it, it is inherently sandboxed. What we are proposing here is that you basically give the agent two tools: One to explore the APIs it has available to it (returning TypeScript type definitions), and one to execute code against those APIs (input is JavaScript). The latter tool runs the code in a Dynamic Isolate. You can't quite just run Claude Code or Codex in there, since they aren't designed to run in Workers, at least today. But @southpolesteve managed to get OpenCode (a similar harness) running 100% in Workers[1]. It's also not as hard as you might think to write your own harness -- I've done it. That said, if your agent's task specifically involves using a bunch of Linux programs, it may still be best to use containers for that. For instance, if your agent is doing software engineering -- checking out a git repo, running a compiler, etc. -- it may be impractical to make that all work in Workers. Try our Sandbox SDK[2] for that. But if your agent is planning a family vacation, it probably doesn't need to run rustc. It probably just needs to interact with a bunch of APIs. And that's where Dynamic Workers shine. blog.cloudflare.com/dynamic-… [0] developers.cloudflare.com/ag… [1] x.com/southpolesteve/status/… [2] developers.cloudflare.com/sa…
To show this off I slopforked the @opencode server so it runs entirely inside a @CloudflareDev Durable Object. No servers. No containers. Hibernates when idle. Try it: opencode attach opencode-do.southpolesteve.w… Code: github.com/southpolesteve/op…
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Sebastien Pahl retweeted
We’re introducing Dynamic Workers, which allow you to execute AI-generated code in secure, lightweight isolates. This approach is 100 times faster than traditional containers. cfl.re/4c2NvPl
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Sebastien Pahl retweeted
To show this off I slopforked the @opencode server so it runs entirely inside a @CloudflareDev Durable Object. No servers. No containers. Hibernates when idle. Try it: opencode attach opencode-do.southpolesteve.w… Code: github.com/southpolesteve/op…

OpenCode hasn't hyped it up but remote server support is really good. You can see where this is going. Excited to see the end state of what they build.
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Sebastien Pahl retweeted
Mar 10

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Sebastien Pahl retweeted
People stop asking this question. The answer is yes, it will always be yes. C is absolutely essential to understanding computers.
Feb 15
Do you think learning C programming is worth it in the era of artificial intelligence?
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Soudain je me souviens du traitement en France de la #copyrightdirective en 2019. Idem : la presse était pour, par intérêt direct parce que les ayants-droit lui avaient donné un bout de lard. Résultat, 100 % de la couverture en faveur. 1/2
Résumé de 100 % de la couverture média généralistes de la loi sur l'interdiction des réseaux sociaux aux moins de 15 ans : "super". Unanimité totale, y compris dans les émissions de débats, 0 recul, 0 contradiction. Les seules critiques regrettent que ça n'aille pas assez loin.

ALT Standing Applause GIF

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Résumé de 100 % de la couverture média généralistes de la loi sur l'interdiction des réseaux sociaux aux moins de 15 ans : "super". Unanimité totale, y compris dans les émissions de débats, 0 recul, 0 contradiction. Les seules critiques regrettent que ça n'aille pas assez loin.

ALT Standing Applause GIF

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18 Dec 2025
A good plan with phases allows one to limit the context to 40/50% per phase most of the time. That is where in my experience all models perform their best.
17 Dec 2025
Someone woke up yesterday, decided plan mode wasnt important, and then a bunch of people on the internet decided to broadcast it in the echo chamber. Stop trusting these people. They are not experts.
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Sebastien Pahl retweeted
Some early HC employees will probably remember me joking that it was my divine mission to eliminate YAML from the world. I joked I started HC only to kill YAML. Like, back in 2013. And we (as an industry) were so close! Then Kubernetes came out and fucked it all up.
--- - Kubernetes uses YAML - Helm uses YAML - ArgoCD uses YAML - Ansible uses YAML - GitHub Action uses YAML - Gitlab CI uses YAML - Azure DevOps uses YAML Terraform uses YAML - GCP cloud build uses YAML Get good at YAML
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3 Sep 2025
I'm back to coding full time for work! I have re-joined @Cloudflare after I left there 9 years ago. I'll be working on their container product. Couldn't be happier to be working on problems of that scale again.
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Sebastien Pahl retweeted
Dear EU officials I am co-founder of Klarna one of Europes largest fintech companies. @vonderleyen Please read this about open banking regulation how it needs to be reformed to bring value and innovation. Happy to speak whenever EU ent. help me spread this so she sees it!
NOTE: Using OpenAi Operator at your bank in EU is illegal by law! Web access for assistants was banned years ago as part of “Open banking” Here is the story of why: 15 years ago I stumbled into Sofort in Germany. A company with the idea to build a digital assistant that would interact with your banks poor UI, so you as a user could avoid it. Just like operator. Back then it was script based, not AI but it worked. I was so impressed Klarna bought the company. It has since then processed billions of dollars. But of course banks got scared! What happens if people use the digital assistant only, instead of their bank. And what if the assistant says, stop paying those fees to your bank and let me help you switch? So German banks sued. They claimed privacy concerns. It went to Brussels and a long lobbying and legal fight pursued. This was the beginning of what we today call open banking! I and others spent years fighting over consumers right to use digital assistants, when accessing their banks. We knew this was critical to create real competition, in an industry that has been plagued by excess profits for years. At first Jonathan Hill from UK was responsible and very supportive. But then he left and a German guy came onboard. He was 100% aligned with incumbent banks and we thought the case was lost. However he did a mistake and let some Russian oligarchs take him for a ride on their private jet. And so he was out. Finally @VDombrovskis stepped in. He was smart and supportive but pressure from banks was intense. There was rumors that they were funding privacy groups in Germany, to have them use privacy concerns to kill Open Banking. What if the digital assistant accessed some of your private data? We were about to loose the vote, when the competitive authorities of EU started getting interested. They suspected the banks were lobbying and pursuing this matter for profit reasons to reduce competition(really…). A few weeks before the vote in parliament they raided the offices of some Dutch and Polish banks. Everyone got super nervous and the Open Banking regulation was passed! Almost… A small technical detail was left to EBA (European banking authorities). Should your digital assistant use an API for access to your bank account or the standard web UI you use yourself for accessing your bank? We pushed as hard as we could. We highlighted and said, if your assistant is mandated to use the API that your bank supplies. What if the API don’t support all the same features. Or the API is broken? Don’t worry said regulators. You can complain with authorities 😂 We said at least let the digital assistant, as fall back, use the web UI. Then banks cant cheat, as they will know we can always use the same UI as their human customers. It’s called self regulation. But EBA ignored us. Today web UI access for digital assistants as ChatGPT Operator is illegal by law. And surprise, surprise the open banking API of European banks, continue to be broken, lack functionality and banks add as much friction as they can. We report and see thousands of issues with these APIs every year. And people ask me why open banking has not become a larger success… What do you say @donaldtusk time for a change? Jest potrzebne!
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Sebastien Pahl retweeted
22 Feb 2025
Humanoids, drones, quantum chips- the US is showing signs of renaissance, but who will work the factories of this New Industrial Age? Thanks to Arena Magazine I had an opportunity to explain how we're tackling this problem @Itemfarm in 3 states now, & soon the whole country. 1/
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Sebastien Pahl retweeted
New blog post about why Go is well-designed and the difference between bad design, disagreeing with the goals of a project and "I don't like this". #golang #languagedesign mattjhall.co.uk/posts/go-is-…
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1 Jan 2025
Should I stick with Go or try Rust for a new dev/infra tool I'm prototyping? It would involve cloud provider APIs, containers and co...
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1 Jan 2025
I started my experiments in Go but it's still so early I can change.
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