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Getting Started

PayConnect by LiveAcid is a payment processing platform that streamlines and modernizes payment workflows, optimizing accounts receivable processes. It supports credit card and ACH payments, invoicing, subscription management, and hosted payment pages.

Prerequisites​

  • A PayConnect API key (contact [email protected] to request one)
  • HTTPS client capable of making REST API calls

Environments​

EnvironmentBase URL
Sandboxhttps://dev.payconnect.us/api
Productionhttps://my.payconnect.us/api

Your First API Call​

Verify your API key by creating a session token:

curl -X POST https://dev.payconnect.us/api/auth/session \
  -H "Authorization: Api-Key YOUR_API_KEY" \
  -H "Content-Type: application/json"

A successful response returns a session token:

{
  "sessionToken": "eyJhbGciOiJIUzI1NiIs...",
  "expiresAt": "2026-08-02T12:30:00.000Z"
}

Key Concepts​

Amounts in Dollars​

All monetary amounts in the PayConnect API are represented in dollars (USD). For example, $10.00 is represented as 10.

Rate Limits​

  • 25 requests per second (sustained) per API key
  • Burst allowance of up to 50 concurrent requests
  • Monthly quota of 2,000,000 requests
  • Exceeding limits returns a 429 Too Many Requests response
  • A per-IP safeguard sits above every account tier; see Rate Limiting

Authentication Methods​

PayConnect supports two authentication methods:

  • API Key — used for legacy endpoints (Authorization: Api-Key YOUR_KEY)
  • Session Token — used for current endpoint implementations (x-session-token header, 30-minute expiry)

See the Authentication guide for details.

Idempotency​

To safely retry money-moving requests after a network failure or timeout, send a unique Idempotency-Key header on POST and PUT calls to /api/trx/*, /api/invoices, /api/subscriptions/v2/*, /api/payment/*, and customer payment-method writes.

curl -X POST https://dev.payconnect.us/api/trx/payment \
  -H "Authorization: Api-Key YOUR_API_KEY" \
  -H "Idempotency-Key: 7c3f9b2a-1d4e-4a8c-9b21-3f7a1e2c4d09" \
  -H "Content-Type: application/json" \
  -d '{ "transaction_amount": 10, "account_vault_id": "..." }'

Rules:

  • The header is optional today. Existing integrations work unchanged. The header will become required on a per-partner basis with at least 30 days' notice before any partner is moved into the required list.
  • Value format: 8–255 characters of [A-Za-z0-9_-]. UUIDv4 is recommended. Malformed values return 400 with error: "idempotency_key_invalid".
  • Generate a new key per logical operation. Use the same key when retrying the same operation.
  • Cached for 24 hours. Within that window:
    • Same key + same body → returns the cached response with header Idempotent-Replayed: true. The underlying transaction runs once.
    • Same key + different body → 422 idempotency_key_reused (catches client bugs that reuse a key for a new payment).
    • Same key, two concurrent requests → first runs; the second receives 409 request_in_progress and should retry shortly.

Best practice: generate the key on the client at the moment the user submits a payment, and reuse it across any retry of that submission. Never generate a fresh key inside a retry loop.

Features​

  • Transaction Processing — credit card and ACH payments, refunds, and pre-authorizations
  • Invoice Management — create, send, and track payment invoices via email
  • Subscription Management — recurring billing with automated retries
  • Hosted Payment Pages — PCI-compliant payment forms for secure card collection
  • Tokenization — secure card-on-file storage for returning customers
  • Postbacks — real-time event notifications for transaction and subscription events

Next Steps​