Funding Sessions

Nuvion accepts payments from your users through the funding sessions API. Your server creates a funding session; depending on the rail, the user completes it via a hosted checkout redirect, a USSD prompt on their phone, or an email from Interac. Nuvion notifies you via webhook once the session settles.

Open Banking: the user is redirected to a hosted bank transfer checkout. Supports GBP and EUR.
Mobile money (momo): the user completes a USSD prompt on their supplied msisdn.
Stablecoin: the user is redirected to a hosted crypto checkout.
Interac: the user receives an email from Interac to complete the payment.

Create a funding session

Use POST /funding-sessions, setting funding_type for anything other than Open Banking (which is the default). See Create a funding session for the full request and response field reference.

Transaction limits

Most currency and rail combinations do not enforce fixed transaction limits. The rails listed below do. Minimum and maximum are stated in main currency units for readability only; amount itself is always submitted in the smallest currency unit.

Currency	Scheme	Minimum	Maximum
TZS	Mobile money	1,000	5,000,000
KES	Mobile money	20	250,000

Mobile money channels

For momo, meta.channel must be one of:

Currency	Valid `channel` values
TZS	`TZ-AIRTEL-C2B`, `TZ-TIGO-C2B`, `TZ-HALOTEL-C2B`
KES	`KE-SAFARICOM-C2B`

curl -X POST https://api.nuvion.dev/funding-sessions \
  -H "Authorization: Bearer $NUVION_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 52000,
    "currency": "GBP",
    "account_id": "01HXYZ5503ABCDEFGHJKMNPQRS",
    "redirect_url": "https://yourplatform.com/checkout/complete",
    "unique_reference": "order-2025-111",
    "narration": "Payment for Order #1042",
    "country_code": "GB"
  }'

curl -X POST https://api.nuvion.dev/funding-sessions \
  -H "Authorization: Bearer $NUVION_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 100000,
    "currency": "TZS",
    "account_id": "01HXYZ5503ABCDEFGHJKMNPQRS",
    "unique_reference": "order-2025-112",
    "narration": "Checking",
    "funding_type": "momo",
    "meta": {
      "msisdn": "255712345678",
      "channel": "TZ-AIRTEL-C2B"
    }
  }'

curl -X POST https://api.nuvion.dev/funding-sessions \
  -H "Authorization: Bearer $NUVION_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 100000000,
    "currency": "USC",
    "country_code": "US",
    "funding_type": "crypto",
    "account_id": "01HXYZ5503ABCDEFGHJKMNPQRS",
    "redirect_url": "https://yourplatform.com/checkout/complete",
    "unique_reference": "order-2025-113",
    "narration": "Payment for Order #1043"
  }'

curl -X POST https://api.nuvion.dev/funding-sessions \
  -H "Authorization: Bearer $NUVION_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 10000,
    "currency": "CAD",
    "country_code": "CA",
    "funding_type": "interac",
    "account_id": "01HXYZ5503ABCDEFGHJKMNPQRS",
    "redirect_url": "https://yourplatform.com/checkout/complete",
    "unique_reference": "order-2025-114",
    "narration": "Checking",
    "meta": {
      "name": "Ada Lovelace",
      "email": "ada@example.com"
    }
  }'

Response

{
  "status": "success",
  "message": "Funding session created successfully",
  "data": {
    "id": "01HXYZ5801ABCDEFGHJKMNPQRS",
    "status": "awaiting_user",
    "unique_reference": "order-2025-111",
    "currency": "GBP",
    "amount": 52000,
    "checkout_url": "https://app.nuvion.dev/checkout/01HXYZ5801ABCDEFGHJKMNPQRS",
    "expires_at": 1787943900000
  }
}

{
  "status": "success",
  "message": "Funding session created successfully",
  "data": {
    "id": "01HXYZ5802ABCDEFGHJKMNPQRS",
    "status": "awaiting_user",
    "unique_reference": "order-2025-112",
    "currency": "TZS",
    "amount": 100000,
    "channel": "TZ-AIRTEL-C2B",
    "msisdn": "255712345678",
    "expires_at": 1787944200000
  }
}

{
  "status": "success",
  "message": "Funding session created successfully",
  "data": {
    "id": "01HXYZ5804ABCDEFGHJKMNPQRS",
    "status": "awaiting_user",
    "unique_reference": "order-2025-113",
    "currency": "USC",
    "amount": 100000000,
    "checkout_url": "https://app.nuvion.dev/crypto-deposit/01HXYZ5804ABCDEFGHJKMNPQRS?checkout_id=11111111-1111-1111-1111-111111111111&amount=100000000",
    "checkout_id": "11111111-1111-1111-1111-111111111111",
    "expires_at": null
  }
}

{
  "status": "success",
  "message": "Funding session created successfully",
  "data": {
    "id": "01HXYZ5805ABCDEFGHJKMNPQRS",
    "status": "awaiting_user",
    "unique_reference": "order-2025-114",
    "currency": "CAD",
    "amount": 10000,
    "name": "Ada Lovelace",
    "email": "ada@example.com",
    "reference_number": "CA1111111111",
    "requires_authentication": false,
    "expires_at": null
  }
}

For Open Banking and Stablecoin, redirect the user to checkout_url. For mobile money, the user completes a USSD prompt on their phone; no redirect is needed. For Interac, the user completes payment via an email from Interac; there’s no checkout_url to redirect to.

Update a funding session

After the customer completes an Interac transfer, call PATCH /funding-sessions/{id} to validate the transfer and progress the session’s status. This applies only to interac funding sessions and takes no request body. See Update a funding session for the full response field reference.

curl -X PATCH https://api.nuvion.dev/funding-sessions/01HXYZ5805ABCDEFGHJKMNPQRS \
  -H "Authorization: Bearer $NUVION_API_KEY"

{
  "status": "success",
  "message": "Funding session updated successfully",
  "data": {
    "id": "01HXYZ5805ABCDEFGHJKMNPQRS",
    "entity_id": "01HXYZ5502ABCDEFGHJKMNPQRS",
    "payment_id": "01HXYZ5851ABCDEFGHJKMNPQRS",
    "status": "processing",
    "unique_reference": "order-2025-114",
    "amount": 10000,
    "reference_number": "CA1111111111"
  }
}

Check a funding session’s status

Use GET /funding-sessions/{id} to check the latest status while waiting for a webhook. failure is present once status is failed or expired; check failure.code against the funding session failure codes.

curl https://api.nuvion.dev/funding-sessions/01HXYZ5805ABCDEFGHJKMNPQRS \
  -H "Authorization: Bearer $NUVION_API_KEY"

See Retrieve a funding session for the full response field reference, or List funding sessions to page through sessions for an account.