The Problem
Every time we started a new project, we followed the same pattern:
1. Set up Resend for transactional email 2. Set up Twilio for SMS verification 3. Choose an auth solution (Auth0? Supabase Auth? Custom?) 4. Integrate Stripe for payments 5. Find an SEO tool 6. Pick a translation service
Six different APIs. Six different SDKs. Six different dashboards. Six different billing accounts. Six different sets of documentation.
And every project needed most of these. The same integration work, repeated.
The Solution
LANGR API unifies all of these into a single REST API:
import { LangrClient } from "@langr/sdk";const langr = new LangrClient({ apiKey: "lk_live_..." });
// One SDK, one key, all services:
await langr.mail.send({ / ... / });
await langr.sms.sendOtp({ / ... / });
await langr.auth.sendOtp({ / ... / });
await langr.payment.checkout({ / ... / });
await langr.seo.audit({ / ... / });
await langr.content.generate({ / ... / });
await langr.i18n.translate({ / ... / });
What's Inside
11 Services, 47 Endpoints
| Service | Endpoints | What It Does | |---------|-----------|-------------| | Mail | 4 | Send email, read inboxes, manage domains | | SMS | 4 | Send messages, OTP send/verify, stats | | Auth | 11 | OTP, magic links, Google OAuth, sessions | | Payment | 4 | Stripe checkout, billing portal, webhooks | | SEO | 16 | Audits, keywords, rankings, backlinks, Lighthouse | | Content | 2 | AI content generation (Claude) | | i18n | 2 | Translate to 120+ locales, list locales | | Keys | 4 | API key management | | Billing | 3 | Tier management, usage tracking | | Developers | 2 | Self-service signup | | Health | 2 | Service health checks |
Single Authentication
One API key (lk_live_...) with fine-grained scopes:
mail:send, mail:read, sms:send, sms:otp, auth:otp,
auth:magic-link, auth:google, payment:checkout, seo:audit,
seo:read, content:generate, i18n:translate, admin:keys
Create keys with only the scopes you need. Rotate or revoke anytime.
Single Rate Limit
Instead of managing rate limits across multiple vendors, LANGR uses a single sliding window per API key. Free tier: 30 RPM. Pro: 300 RPM. Simple.
Architecture
LANGR isn't a wrapper that adds latency. It's a gateway that talks directly to the best infrastructure for each service:
- Email: Resend (high deliverability, SPF/DKIM/DMARC)
- SMS: European SMS gateway (direct carrier routes)
- Auth: Supabase + Redis (sessions, OTP storage)
- Payments: Stripe (PCI-compliant)
- SEO: Custom pipeline (VPS-hosted crawlers)
- Content: Claude AI (Anthropic)
- i18n: Claude AI with locale-specific prompts
- 47 REST endpoints
- 120+ supported locales
- 9 RTL languages
- 19 auth scopes
- 0 SDK dependencies
- Start new projects frequently and want faster setup
- Build global products that need multiple locales
- Want to reduce vendor complexity
- Prefer TypeScript-first tooling
- Need a European-hosted, GDPR-compliant option
- Free: 100 requests/day, all services, $0
- Pro: 10,000 requests/day, all services, $49/month
- Enterprise: Unlimited, custom pricing
Each backend is chosen for quality, not cost. We use the same services we'd use if building them separately.
Real Numbers
Who It's For
LANGR is built for developers who:
Pricing
We wanted pricing as simple as the API:
No per-service pricing. No surprise charges. No seat-based billing.
Get Started
It takes 30 seconds:
npm install @langr/sdk
1. Sign up for free 2. Read the docs 3. View the OpenAPI spec