> ## Documentation Index
> Fetch the complete documentation index at: https://docs.onecluster.co/llms.txt
> Use this file to discover all available pages before exploring further.
# Quickstart: Your First API Call in 5 Minutes
> Go from zero to a successful API response in 5 minutes. No banking knowledge required.
This guide assumes nothing. If you've never called an API before, that's fine. We'll explain every step and every term as we go.
By the end of this guide you'll have:
* A registered sandbox account
* A working API key
* Made a real API call and seen a real response
Let's go.
***
## Step 1: Create your account
Go to [ubn-ui.onecluster.co/auth/signup](https://ubn-ui.onecluster.co/auth/signup) and fill in the registration form.
**What you'll need:**
| Field | What to enter | Notes |
| -------------------- | ------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ |
| Company name | Your registered business name | Must match your CAC certificate exactly |
| Email address | A corporate email (e.g. [you@yourcompany.ng](mailto:you@yourcompany.ng)) | Free email services like Gmail will be rejected |
| Password | A strong password | Minimum 8 characters, at least one number and one symbol |
| Phone number | Your Nigerian mobile number | Format: +2348012345678 |
| UBN account number | Your Union Bank account number | This links your partner account to your bank account |
| Terms & NDPR consent | Check both boxes | NDPR is Nigeria's data protection law. You agree to handle customer data responsibly |
The sandbox is completely free and uses no real money. You aren't signing up for a paid service at this stage.
Once you submit the form, two things happen immediately:
1. Your account is created with the status `PENDING_EMAIL_VERIFICATION`
2. We send a one-time password (OTP) to the email address you provided
Keep the page open. You'll need it in the next step.
***
## Step 2: Verify your email
Check your inbox for an email from `noreply@unionbank.ng`. It contains a **6-digit OTP code** (OTP stands for One-Time Password: a short code that expires after a few minutes and can only be used once, like a ticket with a time limit).
Enter that code on the verification screen to confirm your email address.
**If the code doesn't arrive within 2 minutes:**
Check your spam or junk folder first. Automated emails sometimes land there. If it's not there, click "Resend code" on the verification screen. Each new code invalidates the previous one.
**If the code has expired:**
OTP codes expire after 10 minutes. If yours has expired, click "Resend code" to get a fresh one.
Once your email is verified, your account status moves to `PENDING_KYB_REVIEW`. This means your documents are with our onboarding team for review. In sandbox, the review is fast, often within a few hours during business hours.
KYB stands for Know Your Business. It's the process of verifying that your company is real and legitimate. Think of it as the due diligence a bank does before opening a business account. We explain it in full on the [Onboarding: KYB Documents](/onboarding/kyb-documents) page.
***
## Step 3: Get your sandbox API key
Once your account is approved, log in to the sandbox portal at [ubn-ui.onecluster.co](https://ubn-ui.onecluster.co).
Navigate to **Settings → API Keys** and click **Generate sandbox key**.
You'll see a key that looks like this:
```
ubn_sb_a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6
```
**What is an API key?**
Think of an API key like a password for your application. Just as your email password proves that *you* are logging in to your email, an API key proves that *your application* is making a request to our API. Every request you send must include this key so we know it's coming from you.
Copy your API key and store it somewhere safe immediately, like a password manager or your application's environment variables. We only show the full key once. If you lose it, you'll need to generate a new one and update all your code.
Never paste your API key into a public place: not in a GitHub repo, not in a Slack message, not in a forum post. Anyone who has your key can make API calls on your behalf.
Sandbox keys always start with `ubn_sb_`. Production keys start with `ubn_pk_`. That makes it easy to tell them apart at a glance.
***
## Step 4: Make your first API call
Now the fun part. You're going to call the `/health` endpoint. It's a simple check that confirms the API is online and your connection is working.
**What is curl?**
`curl` is a command-line tool for making web requests. Think of it like a web browser, except instead of showing you a webpage, it shows you the raw data the server sends back. It comes pre-installed on Mac, Linux, and Windows 10+. To check if you have it, open your terminal and type `curl --version`.
**What is a terminal?**
A terminal (also called a command prompt, shell, or console) is a text-based window where you type commands. On Mac, search for "Terminal" in Spotlight. On Windows, search for "Command Prompt" or "PowerShell".
### Option A: Using curl (command line)
Open your terminal, paste the command below, and replace `ubn_sb_your_key_here` with the actual key you generated in Step 3:
```bash theme={null}
curl https://api-partner.onecluster.co/health \
-H "Authorization: ApiKey ubn_sb_your_key_here"
```
The `-H` flag adds a **header** to your request. A header is extra information you attach to a request. In this case, you're attaching your API key so the server knows who is asking.
### Option B: Using JavaScript (fetch)
If you prefer JavaScript, paste this into your browser's developer console or a Node.js script:
```javascript theme={null}
const apiKey = "ubn_sb_your_key_here"; // Replace with your actual key
const response = await fetch("https://api-partner.onecluster.co/health", {
method: "GET",
headers: {
"Authorization": `ApiKey ${apiKey}`
}
});
const data = await response.json();
console.log(data);
```
### The response you should see
If everything is working, the `/health` endpoint responds with the text:
```
Healthy
```
The `/health` endpoint returns a plain-text response of `Healthy`. For detailed system status, call the `/status` endpoint instead. It returns a JSON breakdown:
```json theme={null}
{
"status": "healthy",
"gatewayVersion": "1.0.0",
"downstreamBankingApi": "healthy"
}
```
Let's read the `/status` response together:
* `"status": "healthy"`: The API gateway (the front door of the system) is online and accepting requests.
* `"gatewayVersion": "1.0.0"`: The version of the software running the gateway. Useful to know when reading release notes.
* `"downstreamBankingApi": "healthy"`: The connection between the gateway and Union Bank's core banking system is working. If this said `"degraded"`, payments might be slow. If it said `"unhealthy"`, no transactions would be processing.
**You just made your first successful API call. Welcome to UBN BaaS.**
***
## Step 5: What's next
Create a real Nigerian bank account number for a customer or use case. This is usually the first thing partners build.
Transfer money to any Nigerian bank account. Includes idempotency, retries, and real-time status updates.
Receive money from customers with dedicated collection accounts. Perfect for marketplaces and savings apps.
Check BVN, NIN, and CAC numbers to confirm your customers are who they say they are.
***
## Having trouble?
This means your API key wasn't recognised. Check:
1. Did you replace `ubn_sb_your_key_here` with your actual key?
2. Is there a typo or extra space in the key?
3. Is the header format exactly `Authorization: ApiKey your_key_here` (with a space between `ApiKey` and the key itself)?
4. Did you generate a **sandbox** key (starts with `ubn_sb_`)? Production keys won't work in the sandbox environment.
This is usually a network issue. Check:
1. Are you connected to the internet?
2. Is your company firewall blocking outbound HTTPS requests to `api-partner.onecluster.co`? Ask your IT team to whitelist this domain on port 443.
3. Try opening [https://api-partner.onecluster.co/health](https://api-partner.onecluster.co/health) in your web browser. If that fails too, the issue is your network, not your code.
1. Check your spam and junk folders.
2. Make sure you used a corporate email address. Gmail, Yahoo, and Outlook personal accounts are rejected at registration.
3. Wait 2 minutes and click "Resend code".
4. If the email still doesn't arrive after resending, contact [baas-support@unionbank.ng](mailto:baas-support@unionbank.ng) with your registered email address and company name.
KYB (business document) review happens during business hours (Monday to Friday, 8am to 5pm WAT). If it's been more than 1 business day since you submitted your documents, email [baas-support@unionbank.ng](mailto:baas-support@unionbank.ng). Include your Partner ID (shown in your dashboard) so we can locate your account quickly.
On **Mac**: Open Terminal and type `brew install curl` (requires [Homebrew](https://brew.sh)).
On **Windows**: curl is included with Windows 10 build 1803 and later. Open Command Prompt and type `curl --version` to check. If it's not found, download it from [curl.se/windows](https://curl.se/windows).
On **Linux**: Run `sudo apt install curl` (Ubuntu/Debian) or `sudo yum install curl` (CentOS/RHEL).
Alternatively, use the JavaScript example above. It runs in any browser.
If the status shows `"degraded"` or `"unhealthy"`, there may be a temporary issue with one of our systems. Check [api-partner.onecluster.co/status](https://api-partner.onecluster.co/status) for a full breakdown, or visit our status page linked in the top navigation bar.
Still stuck? Email [baas-support@unionbank.ng](mailto:baas-support@unionbank.ng). Include the error message you received and the command or code you ran.