Tutorial: Build a Community Bank

A bank short-code where a caller enters a PIN, then picks from a menu to check their balance (external API), make a deposit (payment API → database) or leave feedback(stored in your tables). By the end you'll have wired up every core node.

Drop a start node, then an input node to capture the PIN into a variable. Wire start → pin.

{ "prompt": "Welcome to Community Bank" }

{
  "prompt": "Enter your 4-digit PIN:",
  "variable": "pin"            // → {{pin}}
}

Add a condition node after the PIN input. The single branch checks that a PIN was entered; connect b1 to the menu and the else handle to an "invalid PIN" end node.

{
  "branches": [
    { "id": "b1", "variable": "pin", "operator": "notEmpty", "value": "" }
  ]
}

Add a menu node. Each option exposes a handle named after its key — wire option 1 → balance, 2 → amount (deposit) and 3 → comment (feedback).

{
  "prompt": "Community Bank",
  "options": [
    { "key": "1", "label": "Check Balance" },
    { "key": "2", "label": "Deposit" },
    { "key": "3", "label": "Feedback" }
  ]
}

For option 1, add an api node that fetches the balance and saves it. Wire its next handle to an end screen that shows {{balance}}, and its errorhandle to a "try again later" end.

{
  "method": "GET",
  "url": "https://api.example.com/balance?msisdn={{msisdn}}",
  "headers": { "Authorization": "Bearer {{token}}" },
  "saveAs": "balance"
}

{ "message": "Your balance is GHS {{balance}}." }

For option 2, capture the amount, validate it with another condition (gt 0), then collect it by posting to your payment API with an apinode. Save the provider's reference so the next step can store it.

{ "prompt": "Enter amount (GHS):", "variable": "amount" }

{
  "branches": [
    { "id": "b1", "variable": "amount", "operator": "gt", "value": "0" }
  ]
}

{
  "method": "POST",
  "url": "https://api.example.com/payments",
  "body": { "amount": "{{amount}}", "msisdn": "{{msisdn}}" },
  "timeoutMs": 8000,
  "saveAs": "paymentReference"   // provider ref → {{paymentReference}}
}

Wire the condition's b1 → api and else→ an "invalid amount" end. The API node exposes two handles:

On next, write the deposit to your table (capturing {{paymentReference}}), then an end confirms it.

{
  "operation": "write",
  "collection": "deposits",
  "assignments": {
    "amount": "{{amount}}",
    "msisdn": "{{msisdn}}",
    "reference": "{{paymentReference}}"
  },
  "saveAs": "depositId"
}

{ "message": "Deposit of GHS {{amount}} received. Ref {{paymentReference}}." }

For option 3 (Feedback), capture a comment into comment and reuse a database write into the feedback table — the same node, a different table.

Open the simulator and dial through each branch. API calls are mocked, so you can verify the next → database path without hitting a live provider. When it looks right, publish and deploy (see Deployments).