Blog | Sentient Arc

Field Notes

Practical explainers on agents, RAG, and automation, written for the people who have to ship and operate these systems.

2026-09-2211 min read

Claude Opus 5.5 Released: Benchmarks, Pricing, Migration

Claude Opus 5.5 is Anthropic's new Opus model, released September 22, 2026. Anthropic says it matches Claude Fable 5.1 on most work for about 40% less than Opus 5, at $4 and $20 per million tokens. Here is what changed and what breaks when you migrate.

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2026-09-228 min read

Grok 4.7 Released: Benchmarks, Pricing, and the API

Grok 4.7 is SpaceXAI's new flagship model for coding and knowledge work, released September 21, 2026 at Grok 4.6's price of $2 and $6 per million tokens. Here is where it leads, where it trails, and what changes in the API.

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2026-09-1410 min read

What Is Grok Bot? SpaceXAI's Always-On AI Teammates, Explained

Grok Bot is SpaceXAI's app for persistent AI teammates that share one cloud computer, sign in to your tools, and act as you. Here is how it works, what it costs, and what to lock down before you hand it your logins.

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2026-08-159 min read

AI Agents vs. Automation vs. an AI Operating System: Which Do You Need?

AI automation runs a fixed path, an agent decides one, and an AI operating system composes many. Here is what each layer does and which one you need first.

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2026-07-178 min read

What Is Vercel eve? The Filesystem-First Agent Framework, Explained

Vercel eve is an open-source, filesystem-first framework for durable AI agents: you define an agent as files in a directory and eve compiles it into a deployable app. Here is how it works, what it costs, and what to harden before you ship it.

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2026-07-107 min read

How to Turn Obsidian Into an AI Second Brain With a Claude Code Skill

An Obsidian vault is just a folder of markdown files, so a Claude Code skill can capture, file, link, and distill your notes for you. Here is how to turn Obsidian into an AI second brain, and where to keep a human in the loop.

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