Frequently asked questions about Cascade
Plain-language answers for businesses, developers and teams new to OTP.
What is Cascade?
Cascade is an API and dashboard for outbound OTP delivery to your user’s phone via WhatsApp and Telegram. It is not virtual-number rental.
What is cascade delivery?
The message goes to WhatsApp or Telegram first. If the messenger is unavailable, Cascade can send SMS. You are charged only for successful delivery.
Does Cascade provide virtual numbers?
No. Cascade sends the code to your user’s number and does not rent disposable phones.
How much does OTP delivery cost?
WhatsApp and Telegram cost 3 ₸ per successful delivery. SMS costs 8 ₸. Packs lower the average unit price.
Is there a subscription fee?
No. You only pay for purchased balance and successful deliveries at the channel rate.
Which channels are available now?
WhatsApp, Telegram, and SMS are available. SMS costs 8 ₸ and unlocks after the first top-up. Bonus balance cannot be spent on SMS.
How do I connect the API?
Create a company account, generate a Bearer key in the cabinet, and call https://cascade.kz/api from your backend only. Setup usually takes about 3 minutes.
How do send and verify work?
Send delivers a one-time code to the user’s phone. Verify checks the code entered by the user and returns the result to your system.
When is balance charged?
Balance is charged under the successful-delivery rules of the selected channel, not merely for an attempt to send.
Where should I store the API key?
Only on the server: in a secret store or environment variables. Never put the key in a browser or mobile app.
How long is an OTP valid?
The default TTL for a six-digit code is 5 minutes. Resend rules and rate limits are covered in the docs.
What if the code does not arrive?
Check delivery status in the cabinet or via API, confirm the number is in international format and the channel is available, then resend within cooldown rules.
How do I top up balance?
Buy a pack or top up from 100 units in the cabinet. Sign-up adds 50 ₸, and a first top-up of 1000 ₸ or more adds a 1000 ₸ bonus.
How is Cascade different from a plain SMS gateway?
It is OTP-first: messengers are cheaper than SMS, with channel cascade, verify API, webhooks and pay-per-successful-delivery.
Where are the docs and OpenAPI?
Docs live at /docs, the endpoint reference at /api, and the schema at /openapi.yaml.
Detailed articles
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What is authentication? — FAQ Cascade
Authentication is verifying a user’s identity. OTP as a factor: phone confirmation via WhatsApp, Telegram or SMS in Cascade. -
What is One Time Password? — FAQ Cascade
One-Time Password is the full name of OTP: a one-time code with a short TTL. Synonym of OTP in Cascade FAQ. -
What is OTP? — FAQ Cascade
OTP (One-Time Password) is a one-time code to the user’s phone. How send/verify works, how it differs from number rental, and how Cascade de... -
What is SMS activation? — FAQ Cascade
SMS activation is often confused with OTP: virtual number rental vs outbound code delivery to your user. A Cascade breakdown. -
What is a verification code? — FAQ Cascade
A verification code is the confirmation code in the product UI. Usually it is the OTP the user enters after delivery to the phone. -
How not to confuse Cascade with SMS-Activate? — FAQ Cascade
SMS-Activate = number rental. Cascade = outbound OTP to your user. How to tell them apart in 10 seconds. -
Can I buy a virtual number in Cascade? — FAQ
No. Cascade does not sell or rent virtual numbers. Only outbound OTP to your user’s number. -
How does Cascade differ from virtual numbers? — FAQ
Virtual/disposable numbers are rental. Cascade is outbound OTP delivery to the user’s real phone. -
How to store the API key safely? — FAQ Cascade
Server-side secrets/env only. Do not put it in the frontend, a mobile build, or a public git repo. -
What if the SMS did not arrive? — FAQ Cascade
Check the channel, balance, phone format, and history status; wait and retry; consider WhatsApp/Telegram. -
What if the user entered the wrong code? — FAQ Cascade
Verify returns an error. Allow a limited number of attempts and offer a resend. -
What is a Bearer token? — FAQ Cascade
The Authorization: Bearer <token> method in the HTTP header for API access. -
What is the channel field? — FAQ Cascade
An explicit channel: whatsapp, telegram or sms. If omitted — the company default from the cabinet. -
What is cascade delivery? — FAQ Cascade
If one delivery method is less cost-effective or less effective, the system uses another. Messages stay cheaper and arrive more often. -
What is the purpose field? — FAQ Cascade
A scenario label (default verification). Helps separate registration, login, and payments. -
What is Cascade’s REST API? — FAQ Cascade
An HTTPS JSON API with /otp/send, /otp/verify, /links/*, /group/send resources. -
Is it suitable for fintech? — FAQ Cascade
As a code delivery channel — yes, but compliance and antifraud remain on your product’s side. -
Is it suitable for QA? — FAQ Cascade
Yes, for checking registration/login flows. Use the team’s test numbers and limits. -
Is it suitable for SaaS? — FAQ Cascade
Yes: invite, login, recover access. See /use-cases/saas and blog posts. -
Is there an API? — FAQ Cascade
Yes. A REST API with Bearer auth: send, verify, short links, group notify. See /api and OpenAPI. -
Is there a personal cabinet? — FAQ Cascade
Yes. In the cabinet — keys, balance/send history, channel settings, and company management. -
Is there OpenAPI? — FAQ Cascade
Yes. The Cascade OTP API has an OpenAPI 3 specification at https://cascade.kz/openapi.yaml for clients and code generation. -
Where to view message history? — FAQ Cascade
In the personal cabinet. Also see notes on /api/history. -
Where are comparisons with alternatives? — FAQ Cascade
The /compare section. Unverified competitor figures are marked. -
Where to check service status? — FAQ Cascade
The /status page. During incidents also check the changelog. -
Which languages is the site in? — FAQ Cascade
UI: ru/en/kk. Switch via cookie/hl. SEO content is primarily in Russian for now. -
Can it be integrated into a mobile app? — FAQ Cascade
Yes, but keep the API key on the backend. The app calls your server; your server calls Cascade. -
How fast do messages arrive? — FAQ Cascade
Usually seconds, but it depends on the channel and network. Messengers often feel faster to users. -
How to start in 2–3 minutes? — FAQ Cascade
Sign up → key → POST /otp/send → POST /otp/verify. Done. -
How to choose a delivery channel? — FAQ Cascade
Start with a messenger for price and UX; SMS as backup. Or the company default/auto logic. -
How to send OTP? — FAQ Cascade
Call POST /api/otp/send with the phone field and a Bearer token. The user gets the code on the chosen channel. -
How to get an API key? — FAQ Cascade
Open the company cabinet, go to API keys, create a key and copy it. Store it only on the server. -
How to top up the balance? — FAQ Cascade
Via the company cabinet (including payment/Kaspi flows in the product). See /api/top-up and /pricing. -
How to verify OTP? — FAQ Cascade
Call POST /api/otp/verify with phone and code. On success the server returns success: true. -
How does Cascade OTP work? — FAQ Cascade
Cascade accepts an API request, delivers a code to a real phone via the chosen channel, and verifies the user’s input. -
How to calculate OTP cost? — FAQ Cascade
Count tokens by channel and packages on /pricing. SMS costs more than messengers. -
How to contact support? — FAQ Cascade
See /contacts and the support email from the product configuration. -
How to link OTP to a user session? — FAQ Cascade
On the backend, link phone/purpose to the user id before send and after a successful verify. -
What use cases are there? — FAQ Cascade
See /use-cases: SaaS, business, developers, QA, automation, marketing, Telegram, and more. -
Where is the full documentation? — FAQ Cascade
/docs, OpenAPI /openapi.yaml, and the /api and /sdk sections. -
What phone number format is required? — FAQ Cascade
Digits; + and spaces are allowed. Normalization produces forms like 7700…; length 10–15 digits. -
How do short links work? — FAQ Cascade
Pass link in /otp/send or use /links/* — the URL is shortened and can go in the same message. -
Can workflows be automated? — FAQ Cascade
Yes — via the REST API and server workers. Do not automate code guessing. -
Can it be used for arbitration? — FAQ Cascade
If you mean delivering OTP to your users — yes. If you mean mass signup on third-party services via virtual numbers — Cascade is not for tha... -
Can it be used for CRM/ERP? — FAQ Cascade
Yes, as a confirmation channel inside processes. See /use-cases/business. -
Can there be multiple API keys? — FAQ Cascade
Yes, create separate keys for environments/services in the cabinet. -
Can a code and a link be sent together? — FAQ Cascade
Yes, pass link in /otp/send — the short link is added to the same message. -
Can the code be resent? — FAQ Cascade
Yes, subject to the per-number rate limit. Do not spam the user. -
Can Telegram be used? — FAQ Cascade
Yes. Telegram is supported as an OTP delivery channel when the company is configured for it. -
Can only SMS be used? — FAQ Cascade
Yes, you can set channel=sms. Note that SMS costs more tokens than messengers. -
Can WhatsApp be used? — FAQ Cascade
Yes. WhatsApp is one of Cascade’s main channels for OTP and short links. -
Is an official SDK required? — FAQ Cascade
You can work over HTTP. /sdk has JS/TS/Python/PHP/Go/Java/C#/Rust examples. -
Is HTTPS required? — FAQ Cascade
Yes. The API is available over HTTPS; call it only from the server. -
Do you need your own DB for OTP? — FAQ Cascade
Cascade stores the code for verify. You need business-scenario statuses, antifraud, and audit. -
What does error 401 mean? — FAQ Cascade
Invalid or missing API token. Check Bearer and that the key is active. -
What does error 422 mean? — FAQ Cascade
Validation, balance, channel, or invalid/expired code — read message in the response. -
What does error 429 mean? — FAQ Cascade
Too many verify attempts. Slow down retries and respect the limits. -
Why is it so cheap? — FAQ Cascade
Cascade delivery prefers more cost-effective channels (messengers), so average cost is lower than classic SMS broadcasts. -
Why choose Cascade? — FAQ Cascade
Price from 3 ₸, quick start ~3 min, WhatsApp+Telegram+SMS, simple API and cabinet. -
What is group notify? — FAQ Cascade
POST /group/send sends text to a WhatsApp group by name or id. -
Can an online store be connected? — FAQ Cascade
Yes: codes for registration/login and short links to an order or payment. -
Is the service suitable for a startup? — FAQ Cascade
Yes. Quick start, a clear API, and lower average cost thanks to messengers. -
What rate limits exist? — FAQ Cascade
There are limits on send frequency (about once a minute per number) and on verify attempts. See /api/rate-limits. -
How much does a message cost? — FAQ Cascade
Marketing orientation — from 3 ₸. Pricing: WhatsApp/Telegram = 3 ₸, SMS = 8 ₸. See current packages on /pricing. -
How long does setup take? — FAQ Cascade
Usually about 3 minutes: registration, key, first send/verify request. -
SMS verification via Cascade
How to confirm a phone by SMS with the Cascade OTP API and when WhatsApp or Telegram is better. -
How long does the code live? — FAQ Cascade
Usually expires_in is about 300 seconds. After expiry a new send is required. -
Are there webhooks? — FAQ Cascade
Outbound webhooks are described in the docs. See /api/webhooks and INTEGRATION docs.
Test Cascade with your own flow
Open the dashboard and test delivery on your own flow.