32 tools,
explained like
you're five.

const greet = name => `Hi ${name} 👋`;

async function price(t) {
  const r = await fetch(`/api/quote/${t}`);
  return r.json();   // waits without freezing the page
}

type Trade = { ticker: string; qty: number };

function buy(t: Trade) { /* … */ }

buy({ ticker: "NVDA", qty: "ten" });
// ✗ Type 'string' is not assignable to type 'number'
// caught in your editor — before anything runs

type Props = { ticker: string; price: number };

export function PriceTag({ ticker, price }: Props) {
  return <span>{ticker}: ${price.toFixed(2)} 📈</span>;
}

export const usd = (n: number) =>
  new Intl.NumberFormat("en-US",
    { style: "currency", currency: "USD" }).format(n);

import http from "node:http";

http.createServer((req, res) => {
  res.end("hello from Node 🟢");
}).listen(3000);

// $ node server.mjs   → http://localhost:3000

$ bun install          # like npm install, faster
$ bun run dev          # run a package.json script
$ bun test             # built-in test runner
$ bun agent.ts         # run TypeScript directly
$ bunx cowsay hi       # Bun's npx

{
  "name": "agent-desk",
  "scripts": {
    "dev": "next dev",
    "test": "vitest run"
  },
  "dependencies":    { "next": "^16.0.0" },
  "devDependencies": { "typescript": "^5.6.0" }
}

$ npx create-next-app@latest my-app
$ npx tsc --noEmit         # type-check only
$ npx -y @modelcontextprotocol/server-filesystem ~/Notes
$ npx prettier --write .

import { useState } from "react";

export function Counter() {
  const [n, setN] = useState(0);
  return (
    <button onClick={() => setN(n + 1)}>
      Clicked {n} times 🎉
    </button>
  );
}

// a Server Component: runs on the server
export default async function Page(
  { params }: { params: Promise<{ ticker: string }> }
) {
  const { ticker } = await params;
  const q = await fetch(`http://api:8000/quote/${ticker}`)
              .then(r => r.json());
  return <h1>{ticker} · {q.price} 📈</h1>;
}

$ npm create vite@latest dash -- --template react-ts
$ cd dash && npm install
$ npm run dev     # → http://localhost:5173, instant HMR
$ npm run build   # → optimized files in dist/

from statistics import mean

def summary(prices: list[float]) -> str:
    change = (prices[-1] / prices[0] - 1) * 100
    return f"avg {mean(prices):.2f}, {change:+.1f}%"

print(summary([101.2, 99.8, 104.5]))
# avg 101.83, +3.3%

# the built-in way
python3 -m venv .venv
source .venv/bin/activate      # Windows: .venv\Scripts\activate
pip install fastapi uvicorn

# the modern way (creates .venv automatically)
uv init desk && cd desk
uv add fastapi uvicorn
# write main.py (see the FastAPI card), then:
uv run uvicorn main:app --reload

from fastapi import FastAPI

app = FastAPI()

@app.get("/quote/{ticker}")
async def quote(ticker: str, days: int = 30):
    return {"ticker": ticker.upper(), "days": days}

# $ uvicorn main:app --reload
# open http://localhost:8000/docs  ✨

curl -si https://api.example.com/v1/quotes/NVDA \
  -H "Authorization: Bearer $API_KEY"

# HTTP/1.1 200 OK
# content-type: application/json
{ "ticker": "NVDA", "price": 181.4, "currency": "USD" }

import hmac, hashlib, os
from fastapi import FastAPI, Request, HTTPException

app = FastAPI()
SECRET = os.environ["WEBHOOK_SECRET"].encode()

@app.post("/hooks/github")
async def github(req: Request):
    body = await req.body()      # raw bytes!
    mac = hmac.new(SECRET, body, hashlib.sha256)
    sig = "sha256=" + mac.hexdigest()
    got = req.headers.get("x-hub-signature-256", "")
    if not hmac.compare_digest(sig, got):
        raise HTTPException(401)
    # queue the work, reply right away
    return {"ok": True}

const { data, error } = await supabase
  .from("trades")
  .select("ticker, qty, price")
  .eq("ticker", "NVDA")
  .order("created_at", { ascending: false });

create extension vector;

create table notes (
  id bigserial primary key,
  body text,
  embedding vector(768)
);

-- 5 notes closest in meaning to the query
select body from notes
order by embedding <=> $1   -- cosine distance
limit 5;

messages = [{"role": "user", "content": question}]

for step in range(10):                  # hard cap!
    reply = llm.invoke(messages, tools=TOOLS)
    messages.append(reply)
    if not reply.tool_calls:              # model is done
        break
    for call in reply.tool_calls:          # act
        result = TOOLS[call.name](**call.args)
        messages.append(tool_result(call, result))  # observe

print(messages[-1].content)

// store facts
MERGE (n:Company {name:"Nvidia"})
MERGE (t:Company {name:"TSMC"})
MERGE (t)-[:SUPPLIES]->(n);

// ask a connected question
MATCH (s)-[:SUPPLIES]->(:Company {name:"Nvidia"})
RETURN s.name    // → "TSMC"

from langchain_ollama import ChatOllama
from langchain_core.prompts import ChatPromptTemplate

prompt = ChatPromptTemplate.from_template(
    "Summarise this filing in 3 bullets:\n{doc}")
llm = ChatOllama(model="qwen3")

chain = prompt | llm          # pipe = connect parts
chain.invoke({"doc": filing_text})

from langgraph.graph import StateGraph, START, END

g = StateGraph(DeskState)
g.add_node("research", research)   # pulls OpenBB data
g.add_node("decide", decide)       # LLM reasons
g.add_edge(START, "research")
g.add_edge("research", "decide")
g.add_conditional_edges("decide", route,
    {"need_more": "research", "done": END})  # 🔁 loop

app = g.compile(checkpointer=memory)

prompts: [file://prompts/summarise.txt]
providers:
  - ollama:chat:qwen3
  - ollama:chat:gemma3
defaultTest:          # keep the judge local too
  options: { provider: ollama:chat:qwen3 }
tests:
  - vars: { doc: file://filings/aapl.txt }
    assert:
      - type: contains
        value: "revenue"
      - type: llm-rubric
        value: "Exactly 3 bullets, no invented numbers"

from openbb import obb

df = obb.equity.price.historical(
    "NVDA", start_date="2026-01-01",
    provider="yfinance"
).to_df()

macro = obb.economy.fred_series("DGS10")  # 10Y yield · free FRED key

# $ pip install openbb-platform-api
# $ openbb-api   → REST at http://127.0.0.1:6900

FROM python:3.13-slim
COPY --from=ghcr.io/astral-sh/uv:latest /uv /bin/uv
WORKDIR /app
COPY pyproject.toml uv.lock ./
RUN uv sync --locked --no-install-project --no-dev  # cached layer
# .dockerignore must list .venv
COPY . .
ENV PATH="/app/.venv/bin:$PATH"
CMD ["uvicorn", "main:app", "--host", "0.0.0.0"]

# $ docker build -t desk .
# $ docker run -p 8000:8000 desk

ssh root@203.0.113.10
adduser deploy && usermod -aG sudo deploy
apt update && apt upgrade -y
apt install -y ufw
ufw allow OpenSSH && ufw allow 80,443/tcp && ufw enable
# copy your SSH key, then disable password login
curl -fsSL https://get.docker.com | sh

apiVersion: apps/v1
kind: Deployment
metadata: { name: desk-api }
spec:
  replicas: 3                     # keep 3 running
  selector: { matchLabels: { app: desk-api } }
  template:
    metadata: { labels: { app: desk-api } }
    spec:
      containers:
        - name: api
          image: ghcr.io/you/desk:1.4.0
          ports: [{ containerPort: 8000 }]

# first visitor in Dubai — fetched from origin
HTTP/2 200
cache-control: public, max-age=31536000, immutable
cf-cache-status: MISS

# everyone after — served from the Dubai edge
HTTP/2 200
cf-cache-status: HIT
age: 3600