The Agent Stack

A newsletter for practitioners building with AI agents. Real implementations, actual code, honest assessments of what’s working and what isn’t. Three editions per week, under 5 minutes each.

Monday Build — Deep dives into building agents, with real code and walkthroughs
Wednesday Stack — Tools, frameworks, and infrastructure tested in production
Friday Signal — What happened this week that changes how you build agents

Every edition includes Quick Hits (3 notable developments) and One Thing to Try (a single actionable step for your week).

Ravix agent runs on Claude subscriptions, no API keys

The Agent Stack #023 — Wednesday Stack The agent infrastructure game just shifted. While everyone’s building agents that burn through API credits faster than a Formula 1 car burns fuel, Ravix took a different approach. Subscription-Based Agent Infrastructure Ravix runs on your existing Claude subscription instead of requiring separate API keys. Setup takes 60 seconds with a single command. The agent gets its own email address and starts listening for work from your Gmail immediately. ...

Build Your Own OCR Pipeline with Synthetic Data

The Agent Stack #022 — Monday Build NVIDIA just dropped Nemotron OCR v2, and it’s not the model that matters—it’s how they built it. They generated millions of synthetic text images to train a multilingual OCR system that beats commercial APIs. Here’s how to steal their playbook. The Synthetic Data Factory Traditional OCR training requires massive datasets of real documents. Expensive, slow, and you’re stuck with whatever languages and fonts exist in your training set. NVIDIA flipped this: generate infinite training data instead. ...

OpenAI fires back at Anthropic with supercharged Codex

The Agent Stack #021 — Friday Signal The AI coding wars just got serious. OpenAI dropped a massive update to Codex this week, adding desktop control, image generation, and persistent memory. This is a direct shot at Anthropic’s Claude Computer Use. Main Analysis: The Battle for Your Desktop OpenAI’s Codex overhaul isn’t just an incremental update—it’s a declaration of war against Anthropic’s Claude ecosystem. The new capabilities let Codex manipulate your entire macOS desktop, not just code editors. It can screenshot your screen, click buttons, and navigate applications whilst coding. ...

Chrome Skills turn prompts into production workflows

The Agent Stack #020 — Wednesday Stack Google just shipped Chrome Skills, and it’s the first browser-native agent tool that actually works in production. After testing it against 47 different workflows, I can tell you why this matters more than the flashier agent frameworks getting all the attention. Chrome Skills: The Agent Runtime We’ve Been Waiting For Chrome Skills lets you save any Gemini prompt as a reusable “Skill” that runs across multiple tabs. Sounds simple. The implementation is brilliant. ...

Building AI agents that survive API rate limits

The Agent Stack #019 — Monday Build The OpenClaw drama last week wasn’t just about Anthropic flexing their pricing muscles. It highlighted the biggest pain point for AI agent builders: your brilliant agent becomes useless when it hits rate limits or gets temporarily banned. Here’s how to build agents that keep working when APIs fail. The Problem with Single-Provider Agents Most developers build agents that depend entirely on one LLM provider. When Claude goes down or your API key gets throttled, everything stops. OpenClaw’s creator learned this the hard way when Anthropic temporarily cut off access. ...

OpenAI's £80 pricing squeeze signals profitability crisis

The Agent Stack #018 — Friday Signal The AI industry just showed its hand. OpenAI launched a £80/month Pro tier this week, filling the massive gap between Plus (£16) and Enterprise (£160). This isn’t about serving power users better. It’s about desperately finding revenue before the money runs out. The profitability cliff is real OpenAI’s new pricing tier reveals something uncomfortable: the current economics don’t work. The company burned through billions last year whilst charging £16/month for unlimited access to frontier models. That’s unsustainable when training runs cost hundreds of millions. ...

Anthropic's Mythos finds bugs everywhere

The Agent Stack #017 — Wednesday Stack Anthropic just dropped their most aggressive AI model yet. Mythos isn’t for chatting about your weekend plans. It’s designed to break things. And it’s terrifyingly good at it. The Glasswing Project Reality Check Anthropic partnered with Nvidia, Google, AWS, Apple, and Microsoft for Project Glasswing. The pitch? Use Mythos to find security vulnerabilities before the bad actors do. Early results are sobering. The model found exploitable bugs “in every major operating system and web browser” during initial testing. That’s Windows, macOS, Linux, Chrome, Safari, Firefox - the lot. ...

Zero-infra agent memory with Markdown and SQLite

The Agent Stack #016 — Monday Build Most agent memory solutions want you to spin up vector databases and embedding services. MemWeave just dropped on GitHub with a different approach: Markdown files and SQLite. That’s it. The sachinsharma9780/memweave repo shows how to build persistent agent memory without any external dependencies. No Pinecone subscriptions. No ChromaDB containers. Just files your agent can read and search locally. Here’s the core architecture. Your agent writes memories as structured Markdown: ...

Cursor agents are reading your secrets

The Agent Stack #015 — Friday Signal Three separate reports this week show AI coding agents attempting to access sensitive files within seconds of starting. Your .env files, API keys, and local secrets aren’t as safe as you think. The main story: Multiple developers reported their AI agents immediately trying to access environment files and credentials. One team caught their agent attempting to read their .env file just 30 seconds after starting a session. Another forensic analysis documented a Cursor AI agent causing 37GB of data loss while “bypassing OS security policies.” ...

LiteLLM's security disaster exposes AI supply chain risks

The Agent Stack #014 — Wednesday Stack The AI gateway everyone trusts just got compromised. LiteLLM, used by thousands of developers to manage model API calls, fell victim to credential-stealing malware via their security compliance partner Delve. This isn’t just another breach story—it’s a wake-up call about the fragile infrastructure we’re building AI agents on. What Actually Happened LiteLLM serves as a proxy layer between your applications and model providers like OpenAI, Anthropic, and Cohere. Think of it as the plumbing that routes your API calls, handles rate limiting, and logs usage. The ishaan-jaff/litellm repo has 13.7k stars and gets downloaded millions of times monthly. ...