creemio-go

Go SDK for creem.io

Installation

go get -u github.com/evolvedevlab/creemio-go@latest

Initialize the Client

Optional configs can be added as shown below.

package main

import (
    "github.com/evolvedevlab/creemio-go"
    "net/http"
    "os"
)

func main() {
    client := creemio.New(creemio.WithAPIKey(os.Getenv("API_KEY")))
}

With other options:

client := creemio.New(
    creemio.WithAPIKey(os.Getenv("API_KEY")),
    creemio.WithBaseURL(creemio.TestAPIURL),    // Set a custom base URL
    creemio.WithHTTPClient(http.DefaultClient), // Provide a custom HTTP client
)

Error Handling

subscription, response, err := client.Subscriptions.Get(context.Background(), "sub_xxxxx")
if err != nil {
    var apiErr *creemio.APIError
    if errors.As(err, &apiErr) {
        // Handle API-specific error
    }
    // Handle other errors
}

WebHooks

Handling Events

func WebHookHandler(w http.ResponseWriter, r *http.Request) {
    sig := r.Header.Get("creem-signature")
    // Authenticate the webhook signature

    body, err := io.ReadAll(r.Body)
    if err != nil {
        log.Fatal(err)
    }
    defer r.Body.Close()

    var payload creemio.WebHookRequest
    if err := json.Unmarshal(body, &payload); err != nil {
        log.Fatal(err)
    }

    // Handle events
    switch payload.EventType {
    case creemio.WebHookEventSubscriptionActive:
        var sub creemio.WebHookSubscriptionRequest
        if err := json.Unmarshal(body, &sub); err != nil {
            log.Fatal(err)
        }
        // Handle subscription active event
    case creemio.WebHookEventCheckoutCompleted:
        var checkout creemio.WebHookCheckoutRequest
        if err := json.Unmarshal(body, &checkout); err != nil {
            log.Fatal(err)
        }
        // Handle checkout completed event
    default:
        panic("invalid event")
    }
}

For further information, check the offical docs.

Creem Signature Verification

// secret is the webhook token generated from dashboard
func VerifyCreemSignature(r *http.Request, secret string) bool {
	sig := r.Header.Get("creem-signature")
	if len(sig) == 0 {
		return false
	}

	body, err := io.ReadAll(r.Body)
	if err != nil {
		return false
	}

	// Reconstructing the request body for later usage
	r.Body = io.NopCloser(strings.NewReader(string(body)))

	// Generate HMAC-SHA256
	mac := hmac.New(sha256.New, []byte(secret))
	mac.Write(body)
	expectedMAC := mac.Sum(nil)
	expectedSig := hex.EncodeToString(expectedMAC)

	// Constant-time compare
	return hmac.Equal([]byte(sig), []byte(expectedSig))
}

This implementation is same as the JS version in the official docs.

Implemented

• Checkouts
  • GET /v1/checkouts - Get Checkout Session
  • POST /v1/checkouts - Create Checkout Session
• Products
  • POST /v1/products - Create Product
  • GET /v1/products - Get Product
  • GET /v1/products - Get Products List
• Customers
  • GET /v1/customers - Get Customer
  • GET /v1/customers/billing - Get Customer Billing Portal Link
• Transactions
  • GET /v1/transactions - Get Transactions List
• Licenses
  • POST /v1/licenses - Validate License Key
  • POST /v1/licenses - Activate License Key
  • POST /v1/licenses - Deactivate License Key
• Discounts
  • GET /v1/discounts - Create Discount Code
  • POST /v1/discounts - Create Discount Code
  • DELETE /v1/discounts - Delete Discount Code
• Subscriptions
  • GET /v1/subscriptions - Get Subscription
  • POST /v1/subscriptions/{id} - Update Subscription
  • POST /v1/subscriptions/{id} - Upgrade Subscription
  • POST /v1/subscriptions/{id}/cancel - Cancel Subscription

Issues

Some apis still don't work properly. Please check the issues.

Testing

make test