Quickstart

This guide walks you through executing your first authenticated API requests against the Nucleus Core Banking engine.

Prerequisites

Base URL: https://api.onnucleus.com/nucleus/api/v1 (or https://localhost:8443/nucleus/api/v1 locally)
Tenant Identifier: Your institution’s slug, e.g. pilot-mfb
Credentials: Basic Auth username/password or API key issued by your core banking administrator

Step 1: Health & Connectivity

Before making authenticated calls, verify engine connectivity:

curl -k -s https://localhost:8443/nucleus/actuator/health

const res = await fetch("https://localhost:8443/nucleus/actuator/health");
const data = await res.json();
console.log(data); // { status: "UP" }

import urllib.request, json, ssl

ctx = ssl.create_default_context()
ctx.check_hostname = False
ctx.verify_mode = ssl.CERT_NONE

resp = urllib.request.urlopen("https://localhost:8443/nucleus/actuator/health", context=ctx)
print(json.loads(resp.read().decode()))

Step 2: Authenticate and Inspect Permissions

Authenticate against your tenant to receive your session key and assigned permission matrix:

curl -k -X POST "https://localhost:8443/nucleus/api/v1/authentication?tenantIdentifier=pilot-mfb" \
  -H "Content-Type: application/json" \
  -d '{
    "username": "superadmin.pilot-mfb",
    "password": "YourSecurePassword123!"
  }'

Sample Response:

{
  "username": "superadmin.pilot-mfb",
  "userId": 4,
  "base64EncodedAuthenticationKey": "c3VwZXJhZG1pbi5waWxvdC1tZmI6WW91clNlY3VyZVBhc3N3b3JkMTIzIQ==",
  "authenticated": true,
  "officeId": 1,
  "officeName": "Head Office",
  "roles": [
    { "id": 1, "name": "Super user" }
  ],
  "permissions": ["ALL_FUNCTIONS"]
}

Step 3: Fetch Branch Hierarchy

Every operational transaction must originate from a valid operating branch:

curl -k -s "https://localhost:8443/nucleus/api/v1/offices?tenantIdentifier=pilot-mfb" \
  -H "Authorization: Basic c3VwZXJhZG1pbi5waWxvdC1tZmI6WW91clNlY3VyZVBhc3N3b3JkMTIzIQ==" \
  -H "Nucleus-Platform-TenantId: pilot-mfb"

[
  {
    "id": 1,
    "name": "Head Office",
    "hierarchy": "."
  },
  {
    "id": 2,
    "name": "Victoria Island Branch",
    "externalId": "BR-001",
    "hierarchy": ".1."
  }
]

Step 4: Onboard a New Customer

Onboard a customer under Victoria Island Branch (officeId: 2):

curl -k -X POST "https://localhost:8443/nucleus/api/v1/clients?tenantIdentifier=pilot-mfb" \
  -H "Authorization: Basic c3VwZXJhZG1pbi5waWxvdC1tZmI6WW91clNlY3VyZVBhc3N3b3JkMTIzIQ==" \
  -H "Nucleus-Platform-TenantId: pilot-mfb" \
  -H "Content-Type: application/json" \
  -d '{
    "officeId": 2,
    "firstname": "Chinedu",
    "lastname": "Okafor",
    "externalId": "CUST-1002",
    "dateFormat": "dd MMMM yyyy",
    "locale": "en",
    "active": true,
    "activationDate": "12 September 2026",
    "legalFormId": 1
  }'

Sample Response:

{
  "officeId": 2,
  "clientId": 2,
  "resourceId": 2,
  "changes": {
    "cif": "CIF00000002",
    "accountNo": "000000002"
  },
  "resourceExternalId": "CUST-1002"
}

Congratulations! You have verified connectivity, authenticated as an administrator, inspected branch hierarchies, and onboarded your first banking customer.

Overview

Digital Banking & Mobile APIs

Core Banking Workflows

Infrastructure & Operations

Prerequisites

Step 1: Health & Connectivity

Step 2: Authenticate and Inspect Permissions

Sample Response:

Step 3: Fetch Branch Hierarchy

Step 4: Onboard a New Customer

Sample Response:

​Prerequisites

​Step 1: Health & Connectivity

​Step 2: Authenticate and Inspect Permissions

​Sample Response:

​Step 3: Fetch Branch Hierarchy

​Step 4: Onboard a New Customer

​Sample Response:

Prerequisites

Step 1: Health & Connectivity

Step 2: Authenticate and Inspect Permissions

Sample Response:

Step 3: Fetch Branch Hierarchy

Step 4: Onboard a New Customer

Sample Response: