GET /v1/langs — site languages

The smallest endpoint in the API and the one your language switcher has been waiting for. It answers a single question — “which languages does this site speak right now?” — and answers it in the exact order your editors arranged them in the CRM.

Reach for it when you need to:

• render a language switcher in the header without hard-coding en and de in five places;
• check that the language from the URL (/de/pricing) actually exists before you pass it to ?lang;
• generate localized routes, hreflang tags or a sitemap per language.

#List active languages

#Parameters

Nothing to tune here: no path parameters, no query parameters. Just the key.

#Example request

curl https://back.sitecog.com/content/v1/langs \
  -H "x-crm-key: pk_3f9c2a7e1b4d4c0e8a6f5b2d9c1e7a40"

const res = await fetch('https://back.sitecog.com/content/v1/langs', {
  headers: { 'x-crm-key': 'pk_3f9c2a7e1b4d4c0e8a6f5b2d9c1e7a40' },
});

if (!res.ok) throw new Error(`Content API: ${res.status}`);
const langs = await res.json();

console.log(langs.map((l) => l.key)); // ["en", "de"]

// lib/langs.ts — a server-side helper, cached for a minute
export type Lang = { key: string; title: string; index: number };

export async function getLangs(): Promise<Lang[]> {
  const res = await fetch('https://back.sitecog.com/content/v1/langs', {
    headers: { 'x-crm-key': process.env.CRM_KEY! },
    next: { revalidate: 60 },
  });
  if (!res.ok) throw new Error(`Content API: ${res.status}`);
  return res.json();
}

#Example response

[
  { "key": "en", "title": "English", "index": 0 },
  { "key": "de", "title": "German", "index": 1 }
]

#Response fields

An array of objects, one per active language. Three fields each — we did promise it was small.

#Build a language switcher in React

The usual setup: the language lives in the URL (/en/…, /de/…), the switcher is built from /v1/langs, and every content request carries the same code in ?lang. Here is a switcher that knows nothing about specific languages — add Italian in the CRM tomorrow and it simply shows up.

type Lang = { key: string; title: string; index: number };

export function LangSwitcher({ langs, current, path }: {
  langs: Lang[];      // straight from GET /v1/langs
  current: string;    // the language of the page being shown
  path: string;       // the rest of the URL, e.g. "/pricing"
}) {
  return (
    <nav aria-label="Language">
      {langs.map((lang) => (
        <a
          key={lang.key}
          href={`/${lang.key}${path}`}
          hrefLang={lang.key}
          aria-current={lang.key === current ? 'true' : undefined}
        >
          {lang.title}
        </a>
      ))}
    </nav>
  );
}

#Pairing it with ?lang

The key you get here is the key you send everywhere else. Check the code from the URL against the list first: an unknown code in ?lang is a 400 unknown_lang, and nobody wants an error page because someone typed /fr/ by hand.

import { notFound } from 'next/navigation';
import { getLangs } from '@/lib/langs';
import { LangSwitcher } from '@/components/LangSwitcher';

export default async function Home({ params }: { params: Promise<{ lang: string }> }) {
  const { lang } = await params;
  const langs = await getLangs();

  // Unknown language in the URL → a normal 404 instead of a 400 from the API
  if (!langs.some((l) => l.key === lang)) notFound();

  const res = await fetch(`https://back.sitecog.com/content/v1/pages/home?lang=${lang}`, {
    headers: { 'x-crm-key': process.env.CRM_KEY! },
    next: { revalidate: 60 },
  });
  const page = await res.json();

  return (
    <>
      <LangSwitcher langs={langs} current={lang} path="" />
      <h1>{page.content.hero.content.hero_title.content[lang]}</h1>
    </>
  );
}

Need a default for visitors who land on /? That is your call — many sites simply take the first language in the list. The API itself never picks a language for you and never substitutes a missing translation; how to handle gaps gracefully is covered in Languages & fallbacks.

#Errors

The full list with fixes lives on the Errors page.

#Tips from the trenches