Payment notifications
Use webhook and notification records to update merchant systems idempotently.
Payment notifications let a merchant backend react to 0Base state changes without asking the browser to carry money state. A production handler verifies signatures, dedupes event ids, stores delivery evidence, reads current object state when needed, and applies business effects exactly once.
0Base availability is account-gated. Build against capabilities, merchant status, environment mode, and settlement settings instead of assuming that every payment method, asset, network, cadence, or refund path is enabled for every merchant.
0Base product docs and API details
These pages are public product guidance for merchant and platform developers. 0Base endpoint-level API pages are not published for partners yet; use this product documentation to understand the workflow, records, and launch boundaries.
End-to-end picture
This flow is intentionally shown as product infrastructure: 0Base event -> Webhook delivery -> Verify signature -> Dedupe event -> Read current object -> Apply business effect. The merchant application can make the customer experience simple, but the backend should keep each step visible enough for retries, support, and finance closeout.
Production contract
| Boundary | What to build | Why it matters |
|---|---|---|
| Endpoint responsibility | Webhook endpoint belongs to the merchant backend, not the browser. | Keeps payment state trusted. |
| Signature verification | Verify signed test and live events according to API guidance. | Rejects spoofed events. |
| Dedupe | Store event id before side effects. | Prevents duplicate fulfillment. |
| Current-state read | Read payment intent if event ordering is uncertain. | Protects against stale events. |
| Replay handling | Replay failed/dead deliveries safely. | Recovery does not double-apply effects. |
Status and state handling
| State | What it means | Developer action |
|---|---|---|
| Pending delivery | Delivery is queued or not yet delivered. | Wait/monitor. |
| Delivered | Merchant endpoint accepted the event. | Handler still must process idempotently. |
| Dead | Delivery exhausted or failed. | Replay or repair. |
| Processed | Merchant business effect applied once. | Record outcome. |
Status handling should be strict even when the customer UI is friendly. Store raw 0Base statuses, map them to customer-safe labels at the edge, and keep the merchant order state separate from the payment object state. That separation lets you change customer copy without corrupting reconciliation.
Example implementation record
This is an application-side record shape for payment notifications. Keep exact request and response fields aligned with your enabled account contract when 0Base API access is released for your partner account; the point of this record is to keep product, support, and finance joined in your system.
{
"event_id": "evt_base_123",
"delivery_id": "whd_456",
"event_type": "payment_intent.succeeded",
"intent_id": "pi_live_456",
"delivery_status": "delivered",
"signature_verified": true,
"handler_result": "order_fulfilled_once"
}Operational scenario
Webhooks should make the merchant more reliable, not more fragile. If the endpoint is down, 0Base delivery logs and replay give a recovery path, while the merchant handler dedupes event ids to avoid double effects.
In practice, production 0Base integrations make the happy path fast while keeping exceptions predictable: retries return the same object, delayed notifications can be repaired, expired sessions do not become mystery payments, and finance exports can be traced back to the original merchant order.
Before and after
| Before 0Base | With 0Base |
|---|---|
| Browser callback owned fulfillment. | Signed backend notification owns state change. |
| Duplicate events shipped twice. | Event id dedupe makes side effects once-only. |
| Failed deliveries disappeared. | Delivery logs and replay expose recovery. |
| Handlers trusted event order. | Handlers read current object state when needed. |
Evidence to keep
| Evidence | What to store |
|---|---|
| Delivery record | Delivery id, event id, event type, status, attempts, last error. |
| Verification record | Signature result, timestamp, handler version. |
| Dedupe record | Event id, object id, processing status. |
| Business effect | Order status change, ledger update, email/send result. |
| Replay record | Who replayed, why, result, current object status. |
This evidence is what makes the integration supportable at institutional scale. A developer should not need private operational knowledge to answer basic questions such as what the customer saw, which object owns the state, which event announced the change, and which ledger or report row closed the money movement.
Failure modes and recovery
| Failure mode | Recovery |
|---|---|
| Endpoint returns 500 | Delivery retries or becomes dead; replay after fixing handler. |
| Event arrives twice | Return success from dedupe path without repeating fulfillment. |
| Event arrives after manual status read | Compare current object status and apply idempotently. |
| Signature fails | Reject and investigate endpoint configuration. |
Recovery should be idempotent and explainable. When the system is uncertain, preserve the current raw status, read the latest object state, attach a support reference, and avoid changing fulfillment or finance state until a trusted terminal condition is present.
API adjacency
| API area | Use it for |
|---|---|
GET /webhooks/deliveries | List delivery log. |
POST /webhooks/deliveries/{id}/replay | Replay dead delivery. |
POST /webhooks/test | Generate signed test event. |
GET /payment_intents/{intentId} | Read current object state. |
For endpoint-level implementation, use the API reference as the source of truth for fields, enums, authentication, idempotency behavior, pagination, and response examples.
Why this matters for merchants and customers
Payment notifications let merchants react to payment changes without trusting the browser. Signed, idempotent events are essential for reliable commerce because networks and customers do not always move in one synchronous step.
At scale, the value of 0Base is not only that a payment can be created. The value is that the payment can be explained later: what the customer saw, which account capabilities allowed it, which backend state changed, which notification delivered it, and which ledger or report row closed it.
Worked API path
The example below shows the implementation shape for this page. Use merchant-specific capabilities, account settings, and API responses in production; the ids and values here are illustrative.
curl -X GET https://base-api-sandbox.0bit.app/v1/webhooks/deliveries \
-H "Authorization: Bearer $OBIT_SECRET_KEY"Example response shape:
{
"object": "list",
"data": [
{
"object": "webhook_delivery",
"id": "whd_test_123",
"event_id": "evt_test_456",
"event_type": "payment_intent.succeeded",
"intent_id": "pi_test_456",
"status": "delivered",
"attempts": 1,
"last_error": null
}
]
}Implementation checkpoints:
- Store your merchant reference before calling 0Base.
- Attach the returned object id to the same business record.
- Record the request id, idempotency key, raw status, and environment.
- Use webhook and report reads to repair delayed or missed state changes.
Data join map
This join map is the reason 0Base is infrastructure rather than a payment button. A merchant can change checkout UX, support tooling, or finance exports without losing the chain from customer action to backend state and settlement evidence.
Operator runbook
| Signal | Check first | Action |
|---|---|---|
| Customer reports payment not updating | Look up merchant order id, 0Base object id, raw status, and latest webhook delivery. | Read current object state before changing fulfillment. |
| Webhook delivery failed | Check delivery id, event id, attempts, last error, and handler logs. | Fix the handler, replay once, and dedupe by event id. |
| Finance cannot match a row | Compare client reference, intent id, settlement id, report period, and export row. | Move the item to reconciliation queue instead of closing by amount/date. |
The runbook should be available to support and finance teams before launch. A developer integration is not complete if only engineering can explain the state of a customer payment.
Developer checklist
- Verify signatures before parsing business effects.
- Persist event id before side effects.
- Make handlers idempotent.
- Read current object state for terminal changes.
- Monitor dead deliveries.
- Test replay before launch.