The CLSkills blog

159 posts on Claude Code, agents, and prompt engineering. Every claim tested.

FeaturedSep 10, 2026 · 6 min read

AI Predictions 2026, Fact-Checked: 50 Leaders' Claims Scored

Altman, Amodei, Musk, Huang, and 46 others made bold AI claims in 2026. I scored about 150 confirmed, refuted, pending, or unfalsifiable. Free book.

GPT-6 Astra: 12 Things Buried in the System Card and Pricing Page (2026)

GPT-6 Astra launched September 3, 2026. Past the AGI headlines: hidden reasoning, a 272K billing cliff, plan caps, cyber refusals, and where it loses to Claude.

Sep 9, 2026 · 11 min read · gpt-6 astra

Grok Bot: What xAI's Own Docs Admit That the Launch Posts Skip (2026)

Grok Bot runs always-on agents on a cloud computer. xAI's docs say all your bots share one machine and one set of logins. Pricing, limits, what to run first.

Sep 9, 2026 · 11 min read · grok bot

15 Claude Prompts for Small Business Owners That Save Hours (2026)

Fifteen copy-paste Claude prompts for small business owners, grouped by job: bad reviews, refunds, quotes, SOPs, job posts, P&L, social posts, planning.

Sep 8, 2026 · 11 min read · small business

Claude Extended Thinking: When It Helps, When It Wastes Tokens (2026)

What Claude extended thinking is, how to turn it on in the apps and API in 2026, which tasks it helps, which ones waste tokens, and four prompts built for it.

Sep 8, 2026 · 11 min read · extended thinking

Claude Projects Custom Instructions: 6 Templates That Work (2026)

What Claude project instructions are, how they differ from account settings, the six-block structure that holds up, and six copy-paste templates.

Sep 8, 2026 · 11 min read · claude projects

Claude Prompt to Summarize Long Documents Without Missing Anything

Why "summarize this" drops details, plus the two-step Claude prompt that extracts facts, dates and obligations first. Prompts for PDFs, contracts, transcripts.

Sep 8, 2026 · 11 min read · claude summarize

How to Make Claude Write in Your Voice: The Voice Brief Method (2026)

Stop typing "write in my style." Build a one-page voice brief from 3 to 5 samples, store it in a Claude Project, and draft without invented facts.

Sep 8, 2026 · 11 min read · claude writing

How to Stop Claude Using Em Dashes (and Other AI Writing Tells)

Why Claude keeps using em dashes, the instruction wording that actually stops it, where to set it once so it sticks, and a full de-AI edit pass prompt.

Sep 8, 2026 · 11 min read · claude writing

AI Has Now Gotten Lawyers Sanctioned in 1,600+ Cases

A public tracker has logged over 1,600 court cases involving AI-hallucinated citations, hundreds by practicing lawyers, with fines up to $15,000 and real suspensions. Here is what the data shows.

Aug 27, 2026 · 5 min read · ai hallucinations

Claude Skills vs Custom GPTs vs Gemini Gems: Which to Use

The real difference between Claude Skills, ChatGPT Custom GPTs, and Gemini Gems in 2026, and why portability decides which one is worth your time.

Aug 26, 2026 · 4 min read · claude skills

How to Use Claude for Excel and Spreadsheets (2026 Guide)

Build formulas, clean messy data, and automate spreadsheets with Claude. Real prompts, real examples, no jargon. A practical 2026 walkthrough.

Aug 25, 2026 · 6 min read · claude for excel

Verify Claude

Learn how to fact check Claude responses with stacked prompts

Aug 14, 2026 · 3 min read · claude

Self-Host Production AI Agents: 20 You Can Buy and Run

Not prompt files. 20 production AI agents built on LangGraph with security gates and human approval. Self-host, bring your own key, nothing phones home.

Aug 1, 2026 · 9 min read · self-host production AI agents

How AI Can Prevent Exam Paper Leaks in India After NEET 2026

After the NEET 2026 paper leak, here is a real AI exam security architecture: dynamic question paper generation, AI proctoring India, and secure exam software.

Jul 28, 2026 · 8 min read · NEET 2026 paper leak

Claude Usage Credits: How to Enable Them and Set a Cap

Enable Claude usage credits in Settings, then Usage. Set a monthly cap first, then add funds. Fable 5 bills $10/$50 per million tokens, worked examples inside.

Jul 20, 2026 · 7 min read · claude usage credits

Claude Fable 5 Free Access Ends July 19: What to Do

Fable 5 leaves paid Claude plans July 19 at 11:59pm PT. The do-nothing default, usage credits at $10/$50 per million tokens, and whether Sonnet 5 is enough.

Jul 17, 2026 · 7 min read · fable 5 july 19

Block AI Crawlers or Allow Them: 2026 Site Owner Guide

Block AI crawlers or let them in: a copy-paste robots.txt with every verified bot, Cloudflare AI crawlers permission rules, and what I run on my own site.

Jul 15, 2026 · 8 min read · block ai crawlers

Reduce AI Token Costs Without Cutting Output: 2026 Guide

Reduce AI token costs without cutting output: trim context, cache prompts, and stop retries. Real 2026 pricing for ChatGPT, Claude, Gemini, and API users.

Jul 15, 2026 · 7 min read · reduce ai token costs

Claude vs ChatGPT

Discover if Claude outperforms ChatGPT for writing tasks and learn how to improve your AI-generated content

Jul 13, 2026 · 3 min read · claude

Claude Fast Mode Removed July 24: What Breaks and Fix

Claude Opus 4.7 fast mode is deleted July 24, 2026. Requests error, no fallback. Here is the exact migration path to Opus 4.8 and the 3x price cut you get.

Jul 12, 2026 · 8 min read · claude fast mode

Want the tested prompts, not the blog posts?

The Cheat Sheet has 120 tested Claude prompt codes with before-and-after data. The Skills Library has 2,390+ skills. Both lifetime updates.

Get the cheat sheet, $19 Or the Skills Library, $25