What Is Postman?
Postman is a free desktop application that lets you make API calls through a visual interface. Think of it as a remote control for the API: you pick the endpoint, fill in the parameters, press send, and see the response. It is the fastest way to verify that your API key works, understand what a response looks like, and manually test edge cases before you build them into your application. Download it free at postman.com.Getting Started
Download and install Postman
Go to postman.com/downloads and download the version for your operating system (Windows, macOS, or Linux). Create a free Postman account when prompted — you need an account to use the environment and collection features.
Import the UBN BaaS collection
Download the collection JSON file from the repository:In Postman:
- Click Import in the top-left corner.
- Choose File and select the downloaded JSON file.
- Click Import. The collection appears in your left sidebar under Collections.
Create your Postman environment
The collection uses environment variables so you do not have to paste your credentials into every request. Set up an environment to hold your values.In Postman:
- Click the Environments icon in the left sidebar (looks like a slider).
- Click + to create a new environment. Name it
UBN BaaS — Sandbox. - Add the following variables:
| Variable | Initial Value | Description |
|---|---|---|
base_url | https://sandbox.api.unionbank.ng | The sandbox API base URL |
api_key | (your sandbox API key) | From the portal under API Keys |
partner_id | (your Partner ID) | From the portal under Account Settings, e.g. PRT-0001 |
signing_secret | (your signing secret) | From the portal — required for payment and KYC requests |
webhook_secret | (your webhook signing secret) | From the portal under Webhook Settings |
- Click Save.
- In the top-right corner of Postman, select
UBN BaaS — Sandboxfrom the environment dropdown so the collection uses these values.
Verify connectivity with a health check
Expand the collection in the left sidebar. Open the Health folder and click GET Health Check.Press Send. You should receive:If you see this response, your Postman environment is configured correctly and the API is reachable.
Follow the collection folder structure
The collection is organised into folders that match the documentation sections. Work through them in order when first exploring the API:
- Health — connectivity check
- Auth — partner registration and email verification
- KYB — document submission
- API Keys — generate, rotate, revoke
- KYC — BVN, NIN, and CAC verification
- Accounts — create and query virtual accounts
- Payments — account enquiry and transfers
- Collections — receive inbound payments
- Webhooks — register endpoints, view delivery history
Environment Variables Reference
| Variable | Where to Find It | Example Value |
|---|---|---|
base_url | Fixed — use the sandbox URL during development | https://sandbox.api.unionbank.ng |
api_key | Portal → API Keys → Generate Key | sk_sandbox_abc123... |
partner_id | Portal → Account Settings | PRT-0001 |
signing_secret | Portal → API Keys → Signing Secret | signingsecret_abc123... |
webhook_secret | Portal → Webhooks → Signing Secret | whsec_abc123... |
UBN BaaS — Production with base_url set to https://api.unionbank.ng and your production credentials. Switch between environments using the dropdown in the top-right corner — no changes to the requests themselves are needed.
Automatic Headers
The collection includes pre-request scripts that run automatically before each request is sent. You do not need to set these headers manually:X-Correlation-ID
A unique identifier generated for every request. Postman sets this automatically using a UUID. When you report an issue to support, copy this value from the request headers tab — it is how we find your specific request in our logs.
Content-Type
Set to
application/json on all POST and PATCH requests. The pre-request script handles this so you only need to fill in the request body.Request Signing for Payments and KYC
Payment and KYC endpoints require anX-Signature header — a cryptographic signature that proves the request body has not been modified in transit.
The collection includes a pre-request script that computes the HMAC-SHA256 signature automatically using the
signing_secret variable in your environment. You do not need to compute it manually. Just set the signing_secret variable correctly and Postman handles the rest.