Omise Integration

services/omise.ts is a thin HTTP wrapper around Omise’s REST API. No SDK — we use native fetch directly. The package omise-node exists but is loosely maintained and has weak types.

Why no SDK?

Native fetch (Node 20+) has zero deps
Full TypeScript control over response types
Easy to upgrade Omise API version (just bump env)
No SDK breaking changes to worry about
The API surface we use is small: 2 endpoints (POST /charges, GET /charges/:id)

Setup

1. Get Omise TEST keys

Public key (pkey_test_...) — for client-side tokenization (we don’t use this — PromptPay + TrueMoney don’t need it)
Secret key (skey_test_...) — for backend API calls

Save to backend/.env:

OMISE_PUBLIC_KEY=pkey_test_...
OMISE_SECRET_KEY=skey_test_...
OMISE_API_BASE_URL=https://api.omise.co
OMISE_API_VERSION=2019-05-29

2. Roll webhook secret

In Omise dashboard Settings → Webhooks, click Roll secret. Copy the base64 string (only shown once — re-roll if missed).

Save to backend/.env:

OMISE_WEBHOOK_SECRET=<base64 secret>

3. Register webhook URL

Same Webhooks page → set Webhook endpoint to:

https://api.tinadiet.com/webhooks/omise

For local dev with cloudflared tunnel:

https://random-name.trycloudflare.com/webhooks/omise

Click Update. Omise will start delivering events for any charges created on this account.

API calls

Create a charge

const charge = await createOmiseCharge(user, 'promptpay');
// or
const charge = await createOmiseCharge(user, 'truemoney');

Internally calls POST https://api.omise.co/charges with:

PromptPay:

{
  "amount": 15000,
  "currency": "thb",
  "source": { "type": "promptpay" },
  "metadata": {
    "tinadiet_user_id": "2",
    "line_user_id": "Uxxxxxxxx..."
  }
}

TrueMoney:

{
  "amount": 15000,
  "currency": "thb",
  "source": { "type": "truemoney_jumpapp" },
  "return_uri": "https://app.tinadiet.com/premium?omise_return=1",
  "metadata": {
    "tinadiet_user_id": "2",
    "line_user_id": "Uxxxxxxxx..."
  }
}

Response (simplified):

{
  "object": "charge",
  "id": "chrg_test_xxx",
  "status": "pending",
  "amount": 15000,
  "currency": "thb",
  "source": {
    "id": "src_test_xxx",
    "type": "promptpay",
    "scannable_code": {
      "image": {
        "download_uri": "https://api.omise.co/charges/.../downloads/..."
      }
    }
  },
  "authorize_uri": "https://api.omise.co/payments/.../authorize",
  "expires_at": "2026-06-14T07:00:00Z",
  ...
}

Retrieve a charge

const charge = await retrieveOmiseCharge(chargeId);

GET /charges/:id. Used by GET /api/v1/billing/omise/charge/:id polling endpoint to sync state with Omise.

Sync helper

const payment = await syncChargeFromOmise(chargeId);

Combines retrieve + DB update + grant application if status changed to successful. Used as a safety net when webhooks might be delayed.

Charge lifecycle

pending → successful   (paid)
       → failed        (rejected by source)
       → expired       (24h elapsed for PromptPay, less for TrueMoney)
       → reversed      (post-success refund/reverse)

Webhook events fired:

charge.create — initial
charge.complete — status changed to successful
charge.update — any other status change
Possibly more (e.g. charge.refunded); we handle generically

Grant computation

When a charge becomes successful:

const grant = computeGrantWindow(user, PAYMENT_GRANT_DAYS, now);
// grant.starts = max(now, user.premium_expires_at)
// grant.ends = grant.starts + 30 days

paymentsRepository.markCompleted({
  provider_charge_id: charge.id,
  completed_at: charge.paid_at,
  grant_starts_at: grant.starts,
  grant_ends_at: grant.ends,
  ...
});

userRepository.applyPremium(user.id, grant.ends);

The user is updated to plan='premium', premium_expires_at=<grant.ends>.

If user was already premium, the new premium_expires_at is later than the previous one (stacking — see Overview).

TEST mode simulation

Since we don’t have real PromptPay QR or TrueMoney app in TEST:

PromptPay

Create charge from LIFF
QR shows with “TEST MODE” overlay
In Omise dashboard dashboard.omise.co/test/charges, find the charge
Click Capture / Mark as paid
Omise fires charge.complete webhook
Backend processes → premium extended
LIFF polling detects success → modal shows success state

TrueMoney

Create charge from LIFF
LIFF redirects to authorize_uri
Test simulator page appears with 3 buttons:
- Successful → triggers charge.complete
- Failed → triggers status failed
- Pending → leaves as pending
User clicks Successful
Omise redirects back to return_uri with omise_return=1 query
LIFF detects query → reloads billing status

No actual TrueMoney app needed in TEST mode. The simulator is built into Omise’s test environment.

Going LIVE

Client provides Thai business docs (ภพ.20 VAT cert, DBD business registration, bank statement, director ID/passport)
Submit verification in Omise dashboard
Wait approval (3-7 business days typical, up to 14 days)
Request PromptPay + TrueMoney method enablement in submission form
After approval, get LIVE keys from dashboard

Set Railway env:

OMISE_PUBLIC_KEY=pkey_...        (no _test_)
OMISE_SECRET_KEY=skey_...        (no _test_)
OMISE_WEBHOOK_SECRET=...         (new LIVE webhook secret)

In Omise LIVE dashboard, register https://api.tinadiet.com/webhooks/omise as webhook endpoint, roll LIVE secret, set in Railway
No code change needed — backend behaves identically
Test with a single LIVE 150 THB payment using your own card/wallet (refund yourself afterwards to verify refund flow works too)

Caveats

Charge expires_at: PromptPay defaults to 24h, TrueMoney to ~10 minutes. Our LIFF modal countdown reflects Omise’s actual expires_at.
TrueMoney requires app: in LIVE, user MUST have TrueMoney app installed. No fallback to web. Consider warning tooltip near method chip.
expires_at is UTC: convert for display in user TZ.
charge.create arrives before LIFF returns from POST: backend may receive webhook before the POST response completes. The payment row is inserted by POST first; webhook upserts based on UNIQUE constraint (idempotent).