标签：#c

On today’s Uncanny Valley, we unpack OpenAI’s ongoing drama, both legal and reputational, and whether these developments could further hurt the company—particularly in its fight against Anthropic.

Resellers threatened to ditch HP printing supplies for counterfeits.

Today I'm excited to launch RegionCheck , a tool for testing, monitoring, and debugging endpoints from cloud regions around the world. The idea is simple - test an endpoint's DNS and HTTP connectivity and response from a defined set of cloud regions. Whether you're troubleshooting an API, validating a deployment, checking DNS propagation, or investigating latency, seeing the results from multiple cloud regions can quickly reveal issues that aren't obvious from your own machine. What is RegionCheck? RegionCheck lets you run endpoint checks from AWS, Azure, and Google Cloud regions without provisioning infrastructure or maintaining test instances. Current capabilities include: HTTP endpoint testing DNS lookups TLS certificate validation Continuous monitoring with alerts Side-by-side comparison across cloud providers and regions Shareable result pages for collaboration API/MCP access for automation and agents Why I built it When debugging production issues, I often wanted to answer questions like: Is DNS returning the same result everywhere? Or is geo-DNS returning the results intended? Is TLS certificate propagation for my CDN working as intended? Is one region significantly slower than another? Is my CDN caching working as expected? Are my geo-HTTP redirects working as intended? (For some interesting examples try www.yahoo.com and www.cnn.com in non-US regions) There are many tools that exist that provide these answers, but nothing that answers all of these questions in one place. That's what RegionCheck aims to provide. Who it's for RegionCheck is designed for engineers who work with cloud infrastructure, including: DevOps engineers Site Reliability Engineers (SREs) Platform engineers Backend developers Anyone who likes to take a peek at backend infrastructure Try it out RegionCheck is available at https://regioncheck.io You can run free checks directly from the website; or create an account to access monitoring, alerting, the API, and additional features. I'd love

Most people open /etc/hosts , change one line, refresh the browser, and hope. That works until it does not. Then you spend twenty minutes on Permission denied , a forgotten DNS flush, or a commented line from last week that is still active. This is a simple workflow that keeps hosts edits boring. What the hosts file does When your machine resolves a name like myapp.test , it can use a local override before public DNS. Common cases: Point myapp.test to 127.0.0.1 for local work Point a real domain at a staging IP before DNS cutover Temporarily block a host with 0.0.0.0 Give services readable names instead of raw IPs The idea is simple. The mess comes from how people edit and apply it. A workflow that holds up 1. Do not treat /etc/hosts as your only copy Keep a file you own: ~/dev/hosts/personal.hosts Or one file per project / client. Edit that. Apply it on purpose. 2. Edit the copy, then copy it into place macOS / Linux: code ~/dev/hosts/personal.hosts sudo cp /etc/hosts "/etc/hosts.bak. $( date +%Y%m%d-%H%M%S ) " sudo cp ~/dev/hosts/personal.hosts /etc/hosts Windows: edit your copy, back up the live file, then replace: C :\ Windows \ System32 \ drivers \ etc \ hosts You need admin rights for the live file. That is normal. 3. Flush DNS every time you apply Make this part of the apply step, not a later panic search. macOS sudo dscacheutil -flushcache ; sudo killall -HUP mDNSResponder Windows (Admin) ipconfig /flushdns Linux (systemd-resolved) sudo resolvectl flush-caches 4. Verify in the terminal before the browser ping -c 1 myapp.test # Linux: getent hosts myapp.test Right IP in the terminal, wrong page in the browser? Stop rewriting hosts. Look at browser DNS, HTTPS, redirects, or HSTS. 5. Avoid two active lines for the same hostname This breaks people constantly: 10.0.0.5 www.client.com 127.0.0.1 www.client.com Pick one. Comment the other, or better, keep separate profile files and swap the whole file. Example: local frontend + API 127.0.0.1 shop.test 127.0.0.1 api.

E.g. what if someone prompts an LLM to solve the Riemann hypothesis using this or that approach; and the model actually solves it. Who gets the prize?

A competitor intelligence agent enables real-time pricing visibility, automated positioning tracking, and structured competitor briefs for brands without manual research. At the center of these workflows are a researcher agent responsible for gathering data and an analysis agent responsible for generating a summary and a downstream report. However, one of the things that makes the researcher agent's output trustworthy is its retrieval layer, since a poor retrieval-layer output can make the analysis agent's recommendation questionable. If the researcher agent searches the webpage and retrieves a challenge page, an empty response, or blocked content, every downstream conclusion becomes less trustworthy. With a 99.93% success rate on protected websites, ZenRows provides the reliable retrieval layer that makes these workflows practical in production. This tutorial shows why a CrewAI researcher agent can fail on protected competitor pages. It starts with a custom ZenRows-based tool setup, then later shows the MCP server as an alternative approach. Prerequisites This tutorial works best with Python 3.10 or newer. If you are on an older Python version, create a dedicated virtual environment with a current Python installation to avoid dependency conflicts. Python 3.10 to 3.13. CrewAI requires this range. ZenRows API key. Create an account at zenrows.com and copy your key from the dashboard. This key authenticates every scrape the researcher agent runs for data extraction. Anthropic API key. The crew uses Claude to drive both agents. Generate a key in the Anthropic Console. Install dependencies and the required packages using pip install "crewai[anthropic]" crewai-tools zenrows python-dotenv . Create a .env file and save your API keys there. Why the built-in ScrapeWebsiteTool fails on competitor pages The problem, as established earlier, starts before the analysis. A CrewAI workflow depends primarily on the information collected, because a competitor intelligence agent relie

Your customers would rather message you on WhatsApp than fill in a contact form. That's fine at ten conversations a day. At a hundred, messages get missed, nobody knows which rep is on which deal, and at month-end somebody rebuilds the commission sheet by hand and gets it wrong. The usual answer is a $49–$499/month WhatsApp SaaS platform, priced per seat, with your customer data living in someone else's database. This post is the other answer: the same workflow on Google Sheets + Apps Script — and the one piece I see teams get wrong every single time, with the code to fix it. Where DIY WhatsApp automation actually breaks It isn't the messaging. Wiring a WhatsApp webhook into a sheet is a couple of hours of work, and I've written that build up separately — the webhook, the AI reply, and the lock that stops two reps chasing the same lead are all in Build a WhatsApp Sales Inbox in Google Sheets . I won't repeat it here. The part that breaks is the commission math . Someone writes =IF(revenue>10000, revenue*0.08, revenue*0.05) into a column, and three things kill it: A single sale spans two tiers — the formula charges the whole amount at one rate. The tiers change in July , and now every historical row recalculates at the new rate. A customer refunds in August on a sale from June, and nobody can unwind it without breaking the audit trail. So that's what this post builds: a tiered commission engine that survives rule changes and refunds. 1. Put the tiers in a table, never in a formula This is the whole trick. Make a Commission Rules tab, one row per rule: rule_id | rep_id | effective_from | effective_to | tier_1_cap | tier_1_pct | | | | | tier_2_cap | tier_2_pct | tier_3_pct --------+----------+----------------+--------------+------------+------------+----------- R1 | ALL | 2026-01-01 | | 10000 | 0.05 | | | | | 50000 | 0.08 | 0.10 R2 | rep_ayse | 2026-06-01 | | 10000 | 0.06 | | | | | 50000 | 0.09 | 0.12 rep_id is either a specific rep or ALL (the house default). Percenta

I have been working on building a private, secure network accessible from anywhere. The goal was to connect my mobile phone and my local development laptop using a WireGuard VPN , hosting the central gateway on a free-tier Google Cloud Platform (GCP) e2-micro instance. I wanted to access my self-hosted services, specifically my Docker-hosted Open WebUI , running on my local home Wi-Fi connected laptop, directly from my phone using mobile data. It sounded straightforward. But if you read my other from scratch journeys, you might have already guessed, it was not. The Setup My architectural plan was a simple hub-and-spoke topology: The Hub: GCP VM ( 10.66.66.1 ) with IPv4 forwarding enabled. Spoke 1 (My Phone): 10.66.66.2 Spoke 2 (My Laptop): 10.66.66.3 I wrote my server configurations, enabled IP forwarding ( net.ipv4.ip_forward=1 ), wrote the iptables rules to allow forwarding between peers, and started the interfaces. Then came the moment of truth. I tried to bring up the tunnel. Absolute silence. No packet moving from anywhere. Hurdle 1: The Classic Cloud NAT Trap (Internal vs. Public IP) Before I could even worry about routing packets between my phone and laptop, I couldn't even get them to handshake with the GCP server. Like many of us do when working inside a VM, I had run ip addr on the GCP instance to grab its IP address for my client configurations. I set up the WireGuard peers to point to this IP. Nothing connected. The Culprit: GCP (and AWS) operates on a 1:1 NAT mapping. The virtual network interface inside your VM only sees and binds to a private, internal cloud IP (e.g., 10.128.0.x ). The public IP assigned to your instance lives outside the VM at the VPC gateway level. By putting the internal IP into my client configs, my phone and laptop were trying to connect to a private address that didn't exist on their local networks. The Fix: I had to swap the internal IP in the client configurations with the GCP Ephemeral/Static External IP . Once the handshake

From data preparation and tokenizer selection to pretraining, LoRA, RLHF, evaluation, and production monitoring, this guide covers the major stages involved in training an AI model. Training an artificial intelligence model is not simply a matter of loading a dataset onto a GPU and running a few commands. A successful model requires a measurable objective, legally usable and carefully cleaned data, an architecture suited to the problem, controlled optimization, independent evaluation, and continuous monitoring after deployment. In large language model development, a mistake in any one of these stages can waste millions of training examples and a significant amount of compute. This guide explains the model development process primarily through the training of large language models. However, fundamental concepts such as dataset splitting, loss functions, overfitting, and evaluation also apply to computer vision, speech, and predictive models. The goal is not to provide a single fixed recipe. Instead, it is to explain which training approach is appropriate for which problem and to clarify the cost difference between training a model from scratch and adapting an existing model. In Brief: How Is an AI Model Trained? First, the target task and success criteria are defined. Data is collected, reviewed for licensing and privacy, cleaned, and divided into training, validation, and test sets. The model generates predictions from the input data. The difference between the prediction and the correct target is measured using a loss function. Backpropagation calculates how each parameter contributed to the error, and an optimization algorithm updates the parameters. This process is repeated under controlled conditions until the model achieves acceptable results in independent tests and safety evaluations. What Does Training a Model Actually Mean? A neural network initially contains a large number of numerical parameters. During training, the model generates a prediction for a giv

They just annoy me and provide very little value. The non-AI gems in between however are very much still worth reading. Has anybody built that already?

Originally published at daniel-yang.com . I've been using passkeys for a while now, and at some point I noticed an extension in the WebAuthn spec that almost nobody talks about: PRF. It lets a website ask your authenticator to evaluate a pseudo-random function during login. Deterministic output, 32 bytes, keyed to that specific credential, never leaves your browser. That's an encryption key. Sitting inside the same ceremony everyone already uses for login. So I built pknotes to see how far the idea goes: an end-to-end encrypted notes app with no master password anywhere. Your passkey unlocks your notes in the literal, cryptographic sense. This post is the architecture writeup. There's a live demo if you'd rather poke it first (notes wiped daily). One ceremony, two jobs A normal passkey login proves who you are and nothing else. With the PRF extension, the same ceremony does double duty: The server verifies the WebAuthn assertion. That's login. The client reads the PRF output from the same response and derives a key from it. That's decryption. The server never sees the PRF bytes. They're returned to client-side JavaScript only, after user verification (Face ID, Touch ID, PIN), and only for the requesting origin. Requesting it looks like this: const credential = await navigator . credentials . get ({ publicKey : { challenge , userVerification : ' required ' , extensions : { prf : { eval : { first : new TextEncoder (). encode ( ' pknotes/prf-eval/v1 ' ) } }, }, }, }); const prfOutput = credential . getClientExtensionResults (). prf . results . first ; // 32 bytes, deterministic for this credential + this input, never sent anywhere The key hierarchy Raw PRF output shouldn't encrypt data directly, and you also want to be able to add and remove devices without re-encrypting everything. So there's a small hierarchy: Passkey PRF output │ HKDF-SHA256 ▼ KEK (key-encryption key, exists only in browser memory) │ unwraps ▼ Master key (random AES-256, generated once at signup) │