A field guide · 2026 edition

From prompt to agent,
a clear path.

Two years of notes on using AI, gathered for friends drowning in information who haven't found the door yet — one no-detour path, plus the tools, thoughts, and pitfalls along the way.

By Arthur 77 entries 10 sections Updated 2026.09.29

Start the trail
00

Field notes

Field notes · scroll sideways · share to X

09.24tool

Antigravity finally stopped being a chore. /teamwork-preview has a coordinator split the job across specialist agents, /boost checks everything before it acts, and Pro/Ultra quotas went up (check your own account for the numbers). It's crossed from toy to something that can carry light daily work.

09.23voice

Live voice can stay on while you work, but it's a separate model (GPT-Live-1), not the main one answering. I use it to hand out tasks and keep a running work log, not to finish hard jobs in one shot. And Desktop Work voice draws on its own quota — don't open it unless it's actually driving the computer.

09.12agent

Codex sessions can hand work to each other now: one passed its deploy plan to another, which picked it up and paused its own release to avoid a collision. Running several tasks at once, I'm hoping to stop being the one relaying messages between them.

09.11cost

First lesson from GPT-6: watch the tokens. Ultra and multi-agent runs aren't my default — a few agents going at once burns through budget fast. Start on a lower reasoning tier and step up only when the task earns it. Size the effort to the job.

05.20agent

Two weeks into Claude Code, the biggest realization: people who write tests instantly pulled ahead of people who don't. Once the agent finishes, you have exactly one job left — verify. Verification runs on tests.

05.18prompt

Prompt engineering isn't about magic words, it's about stating the task clearly. People who can write a good prompt for Claude get better at product specs, emails, and technical docs too.

05.15local

Local models aren't about saving money — they're about privacy and determinism. Ollama plus a 70B Q4 model handles 60% of daily questions; only the other 40% needs the cloud.

05.12mindset

The beginner's biggest mistake: treating AI as a search engine. It isn't. It's a biased, forgetful, but fluent colleague. Learning to work with a colleague like that is the core skill of this era.

05.10model

Gemini 2.5 Pro's 2M context — I dropped a whole 800-page contract in and asked, and it genuinely remembered a clause on page 30. Five years ago this was science fiction.

05.07agent

MCP is underrated as a protocol. Once agents can call any tool in a standardized way, the moat at the model layer gets hollowed out further — what's left is the moat of 'tools + data'.

01

A few words first

Plain-English basics · explained like you're five

Token

The smallest unit of text an AI reads and writes. Like snipping a sentence into little pieces (a word, half a word) — the AI "thinks" one piece at a time, and each piece is a token.

LLMLarge Language Model

A program that has read enormous amounts of text and learned to "guess the next word." You start it off, it keeps writing. GPT, Claude, and Gemini are all LLMs.

API

The "socket" that lets two pieces of software talk. Your program sends a request in an agreed format; the other side sends the result back in kind. Plugging into an AI means calling its API.

MCPModel Context Protocol

A "universal plug" standard for connecting AI to tools. With it, an AI can reach your calendar, files, and databases the same way — no separate connector built for each one.

Skills

A pre-written "how to do this one thing" manual + materials for the AI. When the task comes up it opens the matching skill and knows the steps and standards. (This page was built by an AI following a skill.)

Agent

An AI that breaks work into steps, calls tools, and carries a whole task through on its own — not just replying, but actually getting the job done.

loopagent loop

The rhythm of AI at work: think a step → reach for a tool → look at the result → think the next step, circling until the job's done. That loop is an agent's "heartbeat."

trace

The full running record of what an AI did step by step — what it thought, which tool it called, what it got back. When something breaks, you retrace it, like a dashcam.

embedding

Turns a piece of text into a string of number-coordinates; the closer in meaning, the closer the coordinates. AI uses it to judge how alike two passages are, and to pull the most relevant bits out of a big pile of material.

RAGRetrieval-Augmented Generation

Before answering, the AI pulls relevant passages from your own library and answers holding those — so it speaks from your material instead of making things up from memory (uses the embedding above to find them).

prompt engineering

Figuring out how to say things to an AI clearly, so it gives you what you want. Same task, different phrasing, wildly different results — that "how to ask" craft is this.

context engineering

One step past "how to ask": managing the whole packet of information you feed the AI each time — what to include, in what order, how much, what to cut. Most of whether it answers well comes down to this.

harness engineering

Building a whole "shell" around the model — tools, the loop above, permissions, how context is managed — turning a model that only chats into an agent that actually does the work. That shell is the harness.

TTSText-to-Speech

Reads written text out loud in a near-human voice. Audiobooks, turn-by-turn navigation, Siri speaking — that's it.

STTSpeech-to-Text

The reverse — turns what you say into text. Dictating to your phone, auto meeting transcripts, voice input — all of it.

GitHub

The site where programmers store code, edit together, and see every change's history. Like Google Docs + cloud storage + revision history, for code.

HTMLHyperText Markup Language

The "skeleton" language for building web pages — it says what headings, paragraphs, images, and buttons a page has. This very page is HTML.

02

Start here · the beginner's path

The six steps · click a node to expand

01 Understand what an LLM actually does 30 min 02 Learn to write a prompt 1 h 03 Pick one main model — 04 Wire it into your workflow 1 week 05 Ship a tiny project 1 weekend 06 Move up to agents / tooling ongoing

Step 01 · 30 min

01

Mental model

Understand what an LLM actually does

Mental model

It isn't looking up answers on Google for you. It's more like someone who's very good at continuing a sentence — you start it off, it guesses "what word most likely comes next," and keeps going. Get this, and the rest stops being confusing.

01 / 06
03

Claude · GPT · Gemini · Grok · DeepSeek

Pick one. Use it for three months. Then reassess.

Claude Opus 5.5My pick

Out Sept 22 · my main pick · Fable 5.1-level work at 40% less than Opus 5 to run

Strengths

  • Anthropic's own numbers: Fable 5.1-level results on most work, for 40% less compute than Opus 5
  • Built up for coding, agents, computer use and knowledge work — and it writes output 30% faster than Opus 5
  • Plainer answers: they reworked how it communicates, so the point comes first and the jargon comes out
  • Writing feel and code reasoning are still the signature — Claude Code is the killer app, and it's the setup I run every day

Weakness

  • Sensitive cybersecurity and biology requests get routed to Opus 4.8 by the safeguards
  • Native image generation still trails GPT; Sonnet 5.5 and Haiku 5.5 haven't shipped yet

Best for · Writing, code, long documents, agents — make it the daily driver, and save Fable for the problem that's genuinely hard

API $4 / $20 per million tokens (in/out), 20% below Opus 5 · on Pro, Max, Team and Enterprise plans
04

AI coding tools

Codex · Claude Code · Antigravity · Grok Build

01

Codex (OpenAI)

agentic Cloud / CLI

OpenAI's official coding agent. Runs in the cloud — give it a repo and a task, it opens a PR itself.

Verdict · Good for: batched, well-defined changes, writing tests. Not for: exploratory work where you think as you go.

02

Claude Code

agentic Terminal

Anthropic's terminal coding agent. Runs in your local shell — reads files, runs commands, runs tests.

Verdict · The strongest local coding agent right now — if you're willing to work in the terminal.

03

Antigravity

ide IDE

Google's agent-native IDE — multiple agents work tasks in parallel, with a built-in verification flow.

Verdict · New, worth watching. The idea is "IDE for agents," not "IDE with AI."

04

Grok Build

agentic Terminal

xAI's coding agent. Runs in the terminal, up to 8 parallel agents, working a plan → search → build loop.

Verdict · Local-first — your code never touches xAI's servers. Arena Mode auto-scores and ranks candidate solutions before you even look.

Other agent frameworks

Hermes Agent — An open-source autonomous agent from Nous Research — self-hosted, runs on your own server 24/7 against whatever model you point it at. Finishes a hard task, writes itself a reusable skill, and gets sharper the more you use it.

DeepSeek Harness — DeepSeek's open-source agent runtime, built "everything is a plugin" — model, tools, and interface are all swappable. Its own definition of an agent is Model + Harness — the exact split behind the "harness engineering" entry above.

Grok Bot — xAI's always-on AI teammates — each bot gets its own cloud computer, signs into your existing tools, and keeps grinding through multi-step work even after you've stepped away.

Gemini Spark — Google's 24/7 personal agent. Runs on Gemini 3.5 and is built on the same Antigravity harness listed under Coding tools above, wired straight into Gmail / Docs / Slides.

Git / collaboration terms

Git — A tool that snapshots your code and records every change, so you can jump back to any old version anytime.

repo — Repository: a folder holding all of a project's code + its history.

commit — Saving a checkpoint: recording what you changed this time with a one-line note. Like a save point in a game.

branch — A side road off the main line to change things, merged back once it works.

fork — Copy someone's whole project under your own name — change it freely without touching the original.

PR — Pull Request: the "I've made changes, please look and decide whether to merge into the main line" request.

05

Prompt library

Copy, fork, replace placeholders

You're my writing partner. I have a rough idea: "{IDEA}".
Please:
1. Distill its core thesis (one sentence)
2. Give three possible angles, each argued in a paragraph
3. Once I pick an angle, give a 5-part outline
Below is code I just wrote. Play a senior engineer:
1. Point out the 3 most worthwhile issues (no more than 3)
2. Give fixes, noting the trade-offs
3. Don't chase "perfect" — chase "maintainable"

```
{CODE}
```
Explain "{TOPIC}" to me Feynman-style:
1. First in a way my 12-year-old could follow
2. Then deepen it with an everyday analogy
3. Finally, point out one common misconception
I'm stuck on a decision: "{DECISION}".
Analyze it with the 10/10/10 framework:
1. Will I regret it 10 minutes from now
2. 10 months from now
3. 10 years from now
Two sentences max each. No pep talk.
06

Projects

Small things, shipped — not planned

01

Choose-an-Agent Skill

A vendor-neutral Claude skill: teaches Ontario buyers/sellers how to judge, interview, and background-check a real-estate agent — and never recommends a specific one (me included). Open source, cloneable.

Claude Skill · TRESA/RECO · MIT

02

Email auto-sorter Agent

A small local agent that scans my inbox daily, sorts mail into 5 buckets, and labels it. Saved me about 4 hours in two weeks.

Claude API · Python · Gmail API

03

Local PDF Q&A tool

Feeds all my contract PDFs into a local vector store for offline Q&A. No internet — a lawyer friend gave it 5/5.

Ollama · Llama 3.1 70B · LangChain

04

Weekly-report generator

Reads git commits and Slack channels, auto-drafts a report every Friday. I only edit 20%.

Claude Code · GitHub API · Slack

05

Home-built MCP server

Exposes my home Synology NAS to Claude so it can read my family-photo metadata and organize albums.

TypeScript · MCP SDK

07

Going deeper with agents

Cloud · Local LLM · Frameworks · Evals

Cloud services

  • Vercel AI SDK — the fastest way to plug into OpenAI / Anthropic / Gemini
  • Replicate / Fal — pay-per-call backends for open-source models
  • Modal / Beam — give your agent an execution environment in the cloud

Local LLMs

  • Ollama — run a local model in one command, best for beginners
  • LM Studio — a GUI, for people who dislike the terminal
  • vLLM — self-hosted inference server, highest throughput
  • Hardware bar: M-series Mac 32GB+, or a 24GB GPU

Agent frameworks

  • MCP (Model Context Protocol) — Anthropic's tool-calling standard
  • LangGraph — state-machine agents, high controllability
  • Mastra — TypeScript-first, great DX

Evals / monitoring

  • Langfuse — open-source LLM observability
  • Braintrust — eval sets + experiment tracking
  • Write the tests first, then the agent. Not the other way around.
08

Resources

No affiliates · no fluff

Free apps worth knowing

09

Real-estate tasks you can hand to an agent

What a realtor can hand to an AI agent

Full auto = the agent runs it, you look at the result; AI drafts · you review = the agent writes, you go line by line — it goes out under your name; Prep automated · you execute = the agent assembles everything, but the signature, the price and the send button stay with you. Not because the machine can't reach them — because that step shouldn't be handed over.

Full auto

Listing copy

房源文案

Give it the specs and selling points, get listing descriptions, social captions, and email blasts (EN + ZH).

How · Claude / GPT on your copy template, run in batches.

Full auto

Marketing design

营销设计

Listing posters, social graphics, just-sold cards and video covers, rendered in bulk from your brand template — several versions to pick from.

How · An image model plus a locked brand template (colours, fonts, credentials line), run in batches.

Full auto

Bilingual comms

双语沟通

Translate and polish client messages, emails, and documents between English and Chinese, keeping tone and professionalism.

How · Any large model; use Gemini / Claude long-context for big files.

Full auto

Neighbourhood briefs

社区资料

Compile schools, amenities, commute, and sale history into a one-page client brief.

How · A web-search agent on a uniform template.

Full auto

Data entry

CRM 录入

Structure contact info from business cards, forms, and emails into your CRM, and tag it.

How · Agent + CRM API / Zapier, on a schedule.

AI drafts

Lead nurture

Lead 跟进

Draft first replies and nurture sequences, personalized by client stage.

How · CRM trigger + LLM draft, you glance before sending.

AI drafts

Multi-platform promotion

多平台宣传

One piece of content reworked for each platform — Xiaohongshu, WeChat, Instagram, YouTube — with the posting schedule laid out.

How · The agent drafts and schedules; you give it a look and confirm the send.

AI drafts

Pricing / CMA draft

定价草稿

Pull comparables into a first-pass CMA draft. You must check the numbers and the comp choices.

How · Data feed + LLM summary, human sets the price.

AI drafts

Scheduling

预约协调

Read intent from email, propose slots, write to the calendar; conflicts go to you.

How · Calendar MCP + agent.

You execute

Contract review

合同条款初审

Key clauses pulled out, watch-points listed, every clause lined up against the template — all assembled by the agent. Whether to change or sign is your call and your lawyer's.

How · Long-context model plus a clause library builds the comparison; a human decides clause by clause.

You execute

Compliance checklist

合规核对

The checklist and supporting documents for the RECO / OREA / FINTRAC process, assembled with gaps flagged up front. The final tick is yours.

How · The agent prepares the list and the paperwork; you tick and you sign.

Want to build your own AI real-estate agent? I wrote a complete hands-on tutorial from scratch — honest about where it stops, and why you still need a real person. Read the tutorial →
AI is a biased, forgetful, but fluent colleague — learning to work with a colleague like that is the core skill of this era.

— Arthur · 2026.09.29

12 years full-time in real estate · Broker · FRI · SRS · ABR · MCNE · CLHMS & GUILD Elite · REAIS