The Loop · Issue N°040

The Loop

A field journal of the AI frontier — for engineers who ship.

Section

Guides

Practical how-tos for AI builders.

· Guides
Guides
Putting Claude on a schedule: routines, loops, and background work
Four shapes for recurring or long-running Claude work — cron schedules, session loops, background tasks, and event hooks. What each one is for, and how not to set money on fire.
Apr 20, 2026 · by AI Blog Editor
by AI Blog Editor
Apr 20, 2026
· Guides
Guides
Writing a CLAUDE.md that actually helps
The file that Claude loads on every turn deserves the same care as a hot code path. What to put in it, what to keep out, and what a useful one looks like.
Apr 20, 2026 · by AI Blog Editor
by AI Blog Editor
Apr 20, 2026
· Guides
Guides
A field guide to Claude Code: CLAUDE.md, hooks, skills, plugins
Four primitives, often confused: the passive memory, the deterministic harness layer, the model-invoked capability, and the bundle. A pragmatic walkthrough, with diagrams and a decision picker.
Apr 20, 2026 · by AI Blog Editor
by AI Blog Editor
Apr 20, 2026
· Guides
Guides
Building agents that actually work
Ten lessons from shipping agent-based features — from loop design to tool discipline to failure modes you will not see in demos.
Apr 20, 2026 · by AI Blog Editor
by AI Blog Editor
Apr 20, 2026
· Guides
Guides
Skills that earn their keep
Not every repeated task deserves a skill. The three tests a skill should pass, and eight scenarios where you guess the right shape.
Apr 20, 2026 · by AI Blog Editor
by AI Blog Editor
Apr 20, 2026
· Guides
Guides
Prompt caching: the cheap win most people skip
The largest single cost lever the Claude API gives you, and it's still the one most teams haven't turned on. How the cache works, how to structure for it, and what it actually saves.
Apr 20, 2026 · by AI Blog Editor
by AI Blog Editor
Apr 20, 2026
· Guides
Guides
Tool use in one picture
Four message shapes cover 95% of tool use. See each one as a live JSON conversation — single call, parallel fan-out, agent loop, forced choice.
Apr 20, 2026 · by AI Blog Editor
by AI Blog Editor
Apr 20, 2026
· Guides
Guides
When extended thinking earns its cost
Thinking helps when the model would commit to the wrong first answer. It doesn't help on tasks the first pass already nailed. A pragmatic guide with a directional chart.
Apr 19, 2026 · by AI Blog Editor
by AI Blog Editor
Apr 19, 2026
· Guides
Guides
The eval harness nobody regrets building
Stop shipping changes on vibes. A small seed set, an honest rubric, a fast grader, and a CI gate. How to build the measurement discipline that keeps you from lying to yourself.
Apr 19, 2026 · by AI Blog Editor
by AI Blog Editor
Apr 19, 2026
· Guides
Guides
Agent loops that don't self-destruct
A loop without a budget, a success signal, and a log is a cost leak with extra steps. Design patterns for agents that stop when they should.
Apr 18, 2026 · by AI Blog Editor
by AI Blog Editor
Apr 18, 2026
· Guides
Guides
RAG on two axes: size × freshness
Place your project on the grid and the right technique is usually one of five. When to paste it in a prompt, when to index, when to just let Claude call your search API.
Apr 17, 2026 · by AI Blog Editor
by AI Blog Editor
Apr 17, 2026