API Reference Overview

Complete reference for all Prism API services, request/response types, and error handling.

Overview

Prism provides a unified gRPC API for payment processing across 100+ payment processors. The API is organized into services that handle different aspects of the payment lifecycle.

Services

Service	Description	Key Operations
Payment Service	Core payment lifecycle	Authorize, Capture, Void, Refund, CreateOrder
Refund Service	Refund operations	Get refund status
Recurring Payment Service	Stored payment methods	Charge, Revoke mandate
Dispute Service	Chargeback handling	Accept, Defend, SubmitEvidence
Event Service	Webhook processing	Handle connector events
Customer Service	Customer management	Create customer
Payment Method Service	Payment method storage	Tokenize
Payment Method Authentication Service	3DS authentication	Pre-authenticate, Authenticate, Post-authenticate
Merchant Authentication Service	Session management	CreateAccessToken, CreateSessionToken, CreateSdkSessionToken

Error Object

All API errors return a structured ErrorInfo object with detailed information about what went wrong.

ErrorInfo Fields

Field	Type	Description
unified_details	UnifiedErrorDetails	Machine-readable unified error code and user-facing message
issuer_details	IssuerErrorDetails	Card issuer-specific error information (scheme, network details)
connector_details	ConnectorErrorDetails	Connector-specific error code and message from the PSP

UnifiedErrorDetails Fields

Field	Type	Description
code	string	Machine-readable error code (e.g., INSUFFICIENT_FUNDS)
message	string	Human-readable error message
description	string	Detailed explanation of the error
user_guidance_message	string	User-facing message with guidance on next steps

IssuerErrorDetails Fields

Field	Type	Description
code	string	Card scheme code (e.g., VISA, MASTERCARD)
message	string	Human-readable message from the issuer
network_details	NetworkErrorDetails	Network-specific error details (advice code, decline code)

NetworkErrorDetails Fields

Field	Type	Description
advice_code	string	Network advice code for retry logic
decline_code	string	Card scheme decline code
error_message	string	Network-specific error details

ConnectorErrorDetails Fields

Field	Type	Description
code	string	Connector-specific error code (e.g., Stripe's card_declined)
message	string	Human-readable message from the connector
reason	string	Detailed explanation of why the error occurred

Error Response Example

{
  "error": {
    "unified_details": {
      "code": "INSUFFICIENT_FUNDS",
      "message": "Your card has insufficient funds.",
      "description": "The payment was declined because the card does not have sufficient available credit or balance to complete the transaction.",
      "user_guidance_message": "Please try a different payment method or contact your bank."
    },
    "connector_details": {
      "code": "card_declined",
      "message": "Your card was declined.",
      "reason": "insufficient_funds"
    },
    "issuer_details": {
      "code": "VISA",
      "message": "Decline",
      "network_details": {
        "advice_code": "01",
        "decline_code": "51",
        "error_message": "Insufficient funds"
      }
    }
  }
}

Domain Schema

See Domain Schema for complete documentation of all data types, enums, and structures used across the API.

Proto Files

The API is defined in Protocol Buffer files located at:

• backend/grpc-api-types/proto/payment.proto - Core payment types and errors

• backend/grpc-api-types/proto/sdk_config.proto - SDK and network error types

• backend/grpc-api-types/proto/services.proto - Service definitions