The Google Autocomplete API for developers

curl -G "https://api.searlo.tech/api/v1/search/suggestions" \
  -H "x-api-key: YOUR_API_KEY" \
  --data-urlencode "q=best running shoes for" \
  --data-urlencode "limit=10" \
  --data-urlencode "hl=en"

import string
import requests

API_KEY = "YOUR_API_KEY"
BASE = "https://api.searlo.tech/api/v1/search/suggestions"

def suggestions(q, limit=10, hl="en"):
    resp = requests.get(
        BASE,
        headers={"x-api-key": API_KEY},
        params={"q": q, "limit": limit, "hl": hl},
    )
    return resp.json()["data"]["suggestions"]

# One call.
print(suggestions("best running shoes for"))

# "Alphabet soup" expansion: one seed term becomes up to 260 long-tail
# phrases (26 letters x up to 10 suggestions each), deduplicated.
seed = "best running shoes for"
expanded = set()
for letter in string.ascii_lowercase:
    for s in suggestions(f"{seed} {letter}"):
        expanded.add(s)

print(f"{len(expanded)} unique long-tail phrases from one seed term")

const API_KEY = "YOUR_API_KEY";
const BASE = "https://api.searlo.tech/api/v1/search/suggestions";

async function suggestions(q, limit = 10, hl = "en") {
  const params = new URLSearchParams({ q, limit: String(limit), hl });
  const resp = await fetch(`${BASE}?${params}`, {
    headers: { "x-api-key": API_KEY },
  });
  const data = await resp.json();
  return data.data.suggestions;
}

// "Alphabet soup" expansion: one seed term becomes many long-tail phrases.
const seed = "best running shoes for";
const expanded = new Set();
for (const letter of "abcdefghijklmnopqrstuvwxyz") {
  const results = await suggestions(`${seed} ${letter}`);
  results.forEach((s) => expanded.add(s));
}

console.log(`${expanded.size} unique long-tail phrases from one seed term`);