E-Transfer API Overview

Complete API reference for Interac e-Transfer (Request For Money) payments

The Flinks Interac (e-Transfer) API lets you initiate a Request For Money (RFM) session and collect payments from end users through Interac e-Transfer. This reference covers the endpoints needed to create a session and retrieve its details.

Base URL

Production / Sandbox: {{BaseUri}}

Authentication

All e-Transfer API requests use OAuth 2.0 Client Credentials flow:

1. Authenticate with Basic auth using Client ID and Secret
2. Receive Bearer token valid for 599 seconds (10 minutes)
3. Use Bearer token for all subsequent API calls
4. Refresh token before expiration

API Endpoints

Authentication

Method	Endpoint	Description
POST	/api/v1/authorize	Obtain access token

Session Management

Method	Endpoint	Description
POST	/api/v2/sessions	Initiate e-Transfer session
GET	/api/v2/sessions/{sessionId}/details	Get session details

Quick Start

1. Authenticate

curl --location '{{BaseUri}}/api/v1/authorize' \
--header 'Content-Type: application/x-www-form-urlencoded' \
--header 'Authorization: Basic {{Username:Password}}' \
--data-urlencode 'grant_type=client_credentials'

2. Initiate Session

curl --location '{{BaseUri}}/api/v2/sessions' \
--header 'Content-Type: application/json' \
--header 'Authorization: Bearer {{access_token}}' \
--data-raw '{
  "referenceId": "USER12345",
  "type": "e-Transfer",
  "direction": "CREDIT",
  "currency": "CAD",
  "amount": 250.00,
  "options": {
    "notificationPreferences": {
      "language": "EN",
      "sendInteracLink": true
    }
  },
  "payor": {
    "firstName": "John",
    "lastName": "Smith",
    "email": "[e-mail]"
  }
}'

3. Launch User Flow

<iframe
  src="{{BaseUri}}/app/?sessionId={{sessionId}}"
  width="100%"
  height="600">
</iframe>

4. Retrieve Session Details

curl --location '{{BaseUri}}/api/v2/sessions/{{sessionId}}/details' \
--header 'Authorization: Bearer {{access_token}}'

Session Object

{
  "sessionId": "850750a4-3021-4061-ac03-a8d873aa4179",
  "referenceId": "USER12345",
  "status": "Completed",
  "type": "e-Transfer",
  "direction": "CREDIT",
  "currency": "CAD",
  "amount": 250.00
}

Session Statuses

Status	Description
Initiated	Session created, awaiting user action
Completed	User has successfully completed the flow
Failed	Session failed (for example, identity or eligibility)
Cancelled	Session was cancelled
Expired	Session timed out before completion

Field Specifications

Character Limits

Field	Limit	Notes
firstName, lastName, middleName	100 characters	Required for identity matching
email	100 characters	Used for notifications and link delivery
referenceId	100 characters	Strongly recommended for tracking
addressLine1	100 characters	Street address
city	100 characters	Full city name
postalCode	6 characters	No spaces (e.g., M5V0T7)
province	2 characters	Provincial code (e.g., ON, QC)
country	2 characters	Only “CA” supported
accountNumber	7–12 characters	Numbers only
transitNumber	5 characters	Numbers only
institutionCode	3 characters	Numbers only

Validation Rules

Amount

• Up to 2 decimal places
• Minimum and maximum are client-configurable via session options.limits

Currency

• Only CAD is supported

Payment Type

• e-Transfer for Interac e-Transfer sessions
• EFT for EFT sessions

Payment Direction

• CREDIT — funds flow to the payee
• DEBIT — funds flow from the payor

Notification Preferences

Control how the end user is notified of the request:

• language — EN or FR
• sendInteracLink — when true, Flinks sends the Interac e-Transfer request link directly to payor.email. When false, you distribute the hosted app URL yourself.

Frontend Integration

iFrame URL Pattern

{{BaseUri}}/app/?sessionId={{sessionId}}

Event Monitoring

window.addEventListener('message', function(e) {
  console.log('e-Transfer Event:', e.data);

  if (e.data.Step === 'SUCCESS') {
    // Session completed successfully
  } else if (e.data.Step === 'EXIT') {
    // User exited the flow
  }
});

Error Handling

Error responses follow the RFC 7807 ProblemDetails format:

{
  "type": "https://tools.ietf.org/html/rfc7231#section-6.5.1",
  "title": "Bad Request",
  "status": 400,
  "detail": "Missing required field: payor.firstName"
}

Common HTTP status codes

Status	Meaning
201	Session created
200	Request succeeded
400	Invalid request payload
401	Missing or invalid access token
403	Access denied

Next Steps

1. Authentication — obtain an access token
2. Initiate Session — create an e-Transfer session
3. Session Details — retrieve session information
4. Setup Guide — complete implementation walkthrough