# tutorial

Learning how programs die, detective-style. This is Part 1 of a three-part series: first, understand the anatomy — CPU, stack, return addresses, segfault — before you can investigate the crime scene and catch the killer. A quiz at every floor. Pass to proceed.

Autopsy trilogy, Part 2. Enter the core dump crime scene, learn the red zone and signal handler roles, then move from coroner to epidemiologist: use a year of citywide death records to solve the first bug, a poisoned well called a bad host.

The autopsy trilogy finale. The remaining 'return-to-null' murders all died during C++ exception unwinding — a teleport, not a normal return. The killer: an 18-year-old race in GNU libunwind, with a murder window one instruction wide (~100 picoseconds). Plus Fermi estimation to check the math.

The browser is not one program; it is a coordinated team. This MOBA-style guide explains Chrome's multi-process architecture, site isolation, and sandboxing: why one tab can crash without dragging the whole browser down with it.

After meeting the browser's five-player team, this post follows the rendering combo: DOM, layout, paint, rasterization, and compositing, all inside a 16ms frame budget. It explains why some animations stay smooth while others jank.

A large language model looks like it is chatting, but underneath it is a mechanical pipeline: text becomes token IDs, IDs become vectors, position is injected, transformer blocks apply attention and feed-forward processing, residual streams keep the stack stable, and logits become the next token.

While managing OpenClaw Gateway, SIGUSR1 enabled config hot-reload through three minutes of instability without killing sessions. A systemctl restart would have sent SIGTERM then SIGKILL and dropped everyone. That difference is today's lesson.

Anthropic killed third-party OAuth tokens, leaving the official Claude CLI as the way to use a subscription programmatically. This guide covers claude -p input methods, output formats, JSON schema, tool whitelisting, sessions, streaming, and wrappers.

You type a URL and press Enter every day, but what actually happens in between? This post uses gu-log as a real-world case study to walk you through 7 floors — from DNS to Service Worker — covering the full journey of a URL.

Why you need a Health Suite and how to detect problems early. From a 36-hour restart storm to healthcheck + watchdog as your first line of defense.

Lv-09 continues from Lv-08, focusing on the Recover Layer. We break down rollback safety design, upgrade SOP decision trees, a `|| true` showstopper caught in code review, and actionable drill KPIs.

Understanding OpenClaw architecture from scratch. Through the eyes of a Python developer, we break down Gateway, WebSocket RPC, Session management, Auth, and more. Quiz at every floor!

Breaking down how OpenClaw connects to Telegram, Discord, and more — plus how AI executes commands, drives a browser, and stays safely leashed. A Python-friendly tour of a TypeScript architecture.

How OpenClaw remembers things, learns new skills, and runs tasks on autopilot. From Embeddings to Cron Jobs — explained for Python developers.

The philosophy behind 1,086 tests. Why tests matter more than code review in the AI era. How to use tests as specs. The changing role of a Tech Lead.

klöss's complete XML prompt framework: 6 core tags + 11 advanced tags, never copy-paste prompts again