Medusa Payment Cybersource for Medusa

CyberSource payment plugin for Medusa.js v2, built on Flex Microform v2 (PCI DSS SAQ-A compliant).

Features

• Flex Microform v2 — card data is tokenized directly at CyberSource; it never touches your server
• Device Fingerprint (ThreatMetrix) — fraud scoring via device profiling before payment
• Authorization + manual capture from the Medusa admin dashboard
• Auto-capture (sale mode) for instant settlement
• Partial and full refunds
• Zero-amount orders — 100% discounts and free orders are handled automatically (no gateway call)
• Admin widget — CyberSource transaction details panel injected into order detail view

Requirements

Installation

npm install medusa-payment-cybersource

Environment Variables

Add these to your .env:

CYBERSOURCE_MERCHANT_ID=your_merchant_id
CYBERSOURCE_KEY_ID=your_shared_key_id
CYBERSOURCE_SECRET_KEY=your_shared_secret_key
CYBERSOURCE_ENV=sandbox           # or "production"
CYBERSOURCE_AUTO_CAPTURE=false    # set to "true" for sale/auto-capture mode

Where to find these values: CyberSource Business Center → Account Management → Transaction Security Keys → Security Keys for the HTTP Signature Security Policy

Configuration

In medusa-config.ts, add the plugin to both plugins (for the API route) and modules (for the payment provider):

import { loadEnv, defineConfig } from "@medusajs/framework/utils"

loadEnv(process.env.NODE_ENV || "development", process.cwd())

module.exports = defineConfig({
  plugins: [
    // Required: registers the built-in /store/cybersource/authorize route
    { resolve: "medusa-payment-cybersource" },
  ],
  projectConfig: {
    // ... your existing config
  },
  modules: [
    {
      resolve: "@medusajs/medusa/payment",
      options: {
        providers: [
          {
            resolve: "medusa-payment-cybersource",
            id: "cybersource",
            options: {
              merchantID: process.env.CYBERSOURCE_MERCHANT_ID,
              merchantKeyId: process.env.CYBERSOURCE_KEY_ID,
              merchantsecretKey: process.env.CYBERSOURCE_SECRET_KEY,
              environment:
                process.env.CYBERSOURCE_ENV === "production"
                  ? "production"
                  : "sandbox",
              capture: process.env.CYBERSOURCE_AUTO_CAPTURE === "true",
            },
          },
        ],
      },
    },
  ],
})

Plugin Options

Payment Flow

Storefront          Backend            CyberSource
    |                  |                    |
    | select method    |                    |
    |----------------->|                    |
    |                  |-- /flex/v2/sessions-->|
    |<-- captureContext JWT ----------------|
    |                  |                    |
    | Flex iFrames render (SAQ-A)          |
    | Fingerprint script loads in bg       |
    |                  |                    |
    | microform.createToken()              |
    |----------------------------------------->|
    |<-- transient_token (JWT 15 min) ---------|
    |                  |                    |
    | POST /store/cybersource/authorize    |
    |  { payment_session_id,              |
    |    transient_token,                 |
    |    fingerprint_session_id }         |
    |----------------->|                    |
    |                  |-- /pts/v2/payments-->|
    |                  |  + deviceInformation |
    |                  |<-- AUTHORIZED --------|
    |<-- { cs_payment_id } -------------|
    |                  |                    |
    | POST /store/carts/:id/complete   |
    |----------------->|                    |
    |                  | authorizePayment() |
    |                  | reads cs_payment_id|
    |<-- order created--|                    |

Frontend Integration

1. Load Flex Microform

<script src="https://flex.cybersource.com/microform/bundle/v2/flex-microform.min.js"></script>

2. Load Device Fingerprint Script

When the user selects CyberSource as payment method, generate a unique session ID and load the ThreatMetrix script. The same ID must be sent in the authorize request.

const fingerprintSessionId = crypto.randomUUID()

const script = document.createElement("script")
script.src = `https://h.online-metrix.net/fp/tags.js?org_id=${ORG_ID}&session_id=${fingerprintSessionId}`
script.async = true
document.head.appendChild(script)

// org_id values:
// Sandbox:    1snn5n9w
// Production: k8vif92e  (confirm in Business Center → Decision Manager)

3. Initialize Flex

// captureContext comes from payment_session.data.captureContext
const flex = new Flex(captureContext)
const microform = flex.microform()

const cardNumber = microform.createField("number", { placeholder: "Card number" })
const cvn = microform.createField("securityCode", { placeholder: "CVV" })

cardNumber.load("#card-number-container")
cvn.load("#cvn-container")

4. Tokenize and Pre-authorize

Call this before placeOrder():

async function authorizePayment(paymentSessionId, fingerprintSessionId) {
  // 1. Get transient token from Flex Microform
  const transientToken = await new Promise((resolve, reject) => {
    microform.createToken({ expirationMonth: "12", expirationYear: "2030" }, (err, token) => {
      if (err) reject(err)
      else resolve(token)
    })
  })

  // 2. Pre-authorize at CyberSource via the built-in plugin route
  const response = await fetch("/store/cybersource/authorize", {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "x-publishable-api-key": YOUR_PUBLISHABLE_API_KEY,
    },
    body: JSON.stringify({
      payment_session_id: paymentSessionId,
      transient_token: transientToken,
      fingerprint_session_id: fingerprintSessionId,  // same UUID used in the script URL
      bill_to: {               // optional but recommended
        firstName: "John",
        lastName: "Doe",
        email: "john@example.com",
        address1: "123 Main St",
        locality: "Guatemala City",
        administrativeArea: "Guatemala",
        postalCode: "01001",
        country: "GT",
      },
    }),
  })

  const result = await response.json()

  if (!response.ok) {
    throw new Error(result.message || "Payment declined")
  }

  return result // { success: true, cs_payment_id, cs_status }
}

// Usage
await authorizePayment(
  cart.payment_collection.payment_sessions[0].id,
  fingerprintSessionId,
)
await placeOrder() // Medusa completes the order using the stored cs_payment_id

/store/cybersource/authorize — Request / Response

Request body:

Success response (200):

{ "success": true, "cs_payment_id": "7278957202756800104005", "cs_status": "AUTHORIZED" }

Declined response (402):

{ "error": "Payment declined", "reason": "INSUFFICIENT_FUND", "cs_status": "DECLINED" }

Device Fingerprint

The plugin sends deviceInformation.fingerprintSessionId and useRawFingerprintSessionId: true to the CyberSource Payments API. The useRawFingerprintSessionId flag is required so that CyberSource looks up ThreatMetrix using the raw session ID (your UUID) instead of the default {merchantId}{sessionId} composite key — which would cause a mismatch with what the frontend script registered.

You can verify fingerprint collection is working by checking a transaction in CyberSource Business Center. A successful integration shows a hash under Device Fingerprint ID instead of "Not Submitted".

Capture Modes

Manual Capture (default)

CyberSource authorizes the card on order placement. You capture the funds from the Medusa Admin → Orders → Payment panel. Authorization expires in 5–7 days if not captured.

Auto-Capture (sale mode)

Set CYBERSOURCE_AUTO_CAPTURE=true. CyberSource processes authorization and capture together; the payment is marked as captured immediately on order placement.

Admin Widget

The plugin injects a CyberSource panel into the order detail page of the Medusa admin (order.details.side.after). It shows:

Status badge logic:

Admin Refund Route

Medusa's default refund UI has a pendingDifference validation that can block refunds in some edge cases. Add this route to your Medusa store for a direct refund bypass:

Create src/api/admin/cybersource/refund/route.ts in your Medusa project:

import { MedusaRequest, MedusaResponse } from "@medusajs/framework"
import { Modules } from "@medusajs/framework/utils"

type RefundRequestBody = {
  payment_id: string
  amount?: number
  note?: string
}

export const POST = async (
  req: MedusaRequest<RefundRequestBody>,
  res: MedusaResponse
) => {
  const { payment_id, amount, note } = req.body

  if (!payment_id) {
    return res.status(400).json({ error: "payment_id is required" })
  }

  const paymentModule = req.scope.resolve(Modules.PAYMENT)

  const payments = await paymentModule.listPayments(
    { id: [payment_id] },
    { relations: ["captures", "refunds"] }
  )
  const payment = payments[0]

  if (!payment) {
    return res.status(404).json({ error: "Payment not found" })
  }

  const captured = (payment.captures ?? []).reduce(
    (sum: number, c: any) => sum + Number(c.amount ?? 0),
    0
  )
  const alreadyRefunded = (payment.refunds ?? []).reduce(
    (sum: number, r: any) => sum + Number(r.amount ?? 0),
    0
  )
  const refundable = captured - alreadyRefunded

  if (refundable <= 0) {
    return res.status(400).json({ error: "No capturable amount available to refund" })
  }

  const refundAmount = amount ?? refundable

  if (refundAmount > refundable) {
    return res.status(400).json({
      error: `Cannot refund ${refundAmount}. Maximum refundable: ${refundable}`,
    })
  }

  const updatedPayment = await paymentModule.refundPayment({
    payment_id,
    amount: refundAmount,
    created_by: (req as any).auth_context?.actor_id,
    note,
  })

  return res.json({ payment: updatedPayment })
}

Call it from your admin UI or custom dashboard:

curl -X POST http://localhost:9000/admin/cybersource/refund \
  -H "Authorization: Bearer <admin_token>" \
  -H "Content-Type: application/json" \
  -d '{ "payment_id": "pay_01...", "amount": 50.00 }'

Development

# Clone
git clone https://github.com/Eleven-Estudio/medusa-payment-cybersource.git
cd medusa-payment-cybersource

# Install dependencies
npm install

# Build
npm run build

# Watch mode (backend only)
npm run dev

Linking to a local Medusa store with yalc

# In the plugin directory
npm run build
npx yalc push

# In your Medusa store directory
npx yalc add medusa-payment-cybersource
npx medusa develop

After any plugin change, re-run npm run build && npx yalc push in the plugin directory, then fully restart the Medusa server (yalc updates node_modules, hot-reload won't pick it up).

CyberSource Resources

• Business Center — sandbox + production portal
• Flex Microform v2 docs
• Payments API reference
• Sandbox test cards

License

MIT