POST
/
headless
/
2025-06
/
{site_id}
/
customers
/
{merchant_id}
/
sessions
curl --request POST \
  --url https://api.loyaltylion.com/headless/2025-06/{site_id}/customers/{merchant_id}/sessions \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "customer": {
    "email": "alice@example.com"
  },
  "session": {
    "page_url": "https://store.example.com/products/100"
  },
  "cart": {
    "kind": "empty"
  }
}'
{
  "channel": "web",
  "currency": "usd",
  "language": "en",
  "customer": {
    "state": "enrolled",
    "id": 123,
    "merchant_id": "<string>",
    "email": "<string>",
    "first_name": "<string>",
    "last_name": "<string>",
    "points_approved": 123,
    "points_pending": 123,
    "points_spent": 123,
    "enrolled_at": "<string>",
    "tier_membership": {
      "tier_id": 123,
      "started_at": "2025-01-01T12:00:00Z",
      "expires_at": "2026-01-01T12:00:00Z",
      "progress": {
        "kind": "points",
        "valid_until": "<string>",
        "points_needed_for_renewal": 123,
        "upgrade_tier_id": 123,
        "points_needed_for_upgrade": 123,
        "tier_points": {
          "now": 123,
          "at_expiration": 123
        }
      }
    },
    "birthday": {
      "month": 6,
      "day": 25
    },
    "next_birthday": "2025-06-25",
    "claimed_rewards": [
      {
        "id": 123,
        "claimed_at": "<string>",
        "reward_id": 123,
        "title": "$5 voucher",
        "state": "approved",
        "source": {
          "kind": "points_redemption",
          "points_cost": 123
        },
        "redeemable": {
          "usage_status": "not_used",
          "kind": "gift_card",
          "code_last_characters": "<string>",
          "initial_balance": {
            "amount": 9.9,
            "formatted": "$9.90"
          },
          "current_balance": {
            "amount": 9.9,
            "formatted": "$9.90"
          },
          "expires_at": "<string>"
        },
        "auto_refund_at": "<string>"
      }
    ],
    "available_rewards": [
      {
        "id": 123,
        "limit": {
          "count": 123,
          "interval": "day"
        },
        "kind": "gift_card",
        "properties": {
          "initial_balance": {
            "amount": 9.9,
            "formatted": "$9.90"
          }
        },
        "variant": {
          "tier_id": 123,
          "title": "$5 voucher",
          "enabled": true,
          "cost": {
            "kind": "fixed",
            "points": 123
          },
          "cost_text": "100 points"
        },
        "context": {
          "can_redeem": {
            "state": "redeemable"
          },
          "last_claimed_at": "<string>",
          "claim_count": 123,
          "claim_limit": {
            "state": "no_limit"
          }
        }
      }
    ],
    "available_rules": [
      {
        "id": 123,
        "limit": {
          "count": 123,
          "interval": "day"
        },
        "kind": "birthday",
        "variant": {
          "tier_id": 123,
          "title": "Make a purchase",
          "enabled": true,
          "result": {
            "kind": "points",
            "per_currency_unit": 1,
            "points": 5
          },
          "result_short_text": "5 points per $1"
        },
        "context": {
          "last_completed_at": "<string>",
          "completion_count": 123,
          "completion_limit": {
            "state": "no_limit"
          }
        }
      }
    ],
    "active_cart_redemptions": [
      {
        "id": "<string>",
        "claimed_reward_id": 123,
        "expires_at": "<string>",
        "product": {
          "id": "<string>",
          "title": "<string>",
          "url": "<string>",
          "image_url": "<string>",
          "variant": {
            "id": "<string>",
            "title": "<string>"
          }
        },
        "quantity": 123,
        "cart_id": "<string>",
        "cart_line": {
          "kind": "shopify",
          "merchandise_id": "gid://shopify/ProductVariant/1001",
          "product_id": "gid://shopify/Product/100",
          "quantity": 1,
          "attributes": [
            {
              "key": "__lion_sfp_id",
              "value": "19fdf4cb"
            }
          ]
        },
        "current_cart_state": {
          "in_cart": true,
          "cart_requirements_met": true,
          "cart_requirements_detail": {
            "minimum_cart_total": {
              "state": "no_requirement"
            },
            "minimum_line_item_quantity": {
              "state": "no_requirement"
            }
          }
        }
      }
    ],
    "referral_urls": {
      "direct": "<string>",
      "facebook": "<string>",
      "twitter": "<string>",
      "email": "<string>",
      "whatsapp": "<string>",
      "device_share": "<string>"
    }
  },
  "configuration": {
    "channel": "web",
    "currency": "usd",
    "language": "en",
    "program": {
      "name": "Lion Rewards"
    },
    "tier_configuration": {
      "boundary_mode": "spend",
      "tiers": [
        {
          "id": 1,
          "name": "Silver",
          "benefit_ids": [
            1
          ],
          "hidden": false,
          "kind": "spend",
          "position": 1,
          "lower_bound": {
            "amount": 0,
            "formatted": "$0"
          },
          "upper_bound": {
            "amount": 99.99,
            "formatted": "$99.99"
          }
        },
        {
          "id": 2,
          "name": "Gold",
          "benefit_ids": [
            1,
            2
          ],
          "hidden": false,
          "kind": "spend",
          "position": 2,
          "lower_bound": {
            "amount": 100,
            "formatted": "$100"
          },
          "upper_bound": null
        }
      ],
      "tier_benefits": [
        {
          "id": 1,
          "label": "Early access to new products",
          "secret": false,
          "details": null
        },
        {
          "id": 2,
          "label": "Free makeup classes",
          "secret": false,
          "details": {
            "plaintext": "Email classes@example.com to sign up to a class\n",
            "html": "<p>Email classes@example.com to sign up to a class</p>"
          }
        }
      ],
      "membership": {
        "mode": "rolling",
        "duration_months": 12
      }
    },
    "referee_incentive": {
      "minimum_spend": {
        "amount": 9.9,
        "formatted": "$9.90"
      },
      "incentive_text": "Get a 10% discount on your order with this code when you spend over $50",
      "kind": "cart_discount_voucher",
      "discount_kind": "percentage",
      "discount": {
        "percentage": 10,
        "formatted": "10%"
      }
    },
    "rules": [
      {
        "id": 123,
        "limit": {
          "count": 123,
          "interval": "day"
        },
        "kind": "birthday",
        "variants": [
          {
            "tier_id": 123,
            "title": "Make a purchase",
            "enabled": true,
            "result": {
              "kind": "points",
              "per_currency_unit": 1,
              "points": 5
            },
            "result_short_text": "5 points per $1"
          }
        ]
      }
    ],
    "rewards": [
      {
        "id": 123,
        "limit": {
          "count": 123,
          "interval": "day"
        },
        "kind": "gift_card",
        "properties": {
          "initial_balance": {
            "amount": 9.9,
            "formatted": "$9.90"
          }
        },
        "variants": [
          {
            "tier_id": 123,
            "title": "$5 voucher",
            "enabled": true,
            "cost": {
              "kind": "fixed",
              "points": 123
            },
            "cost_text": "100 points"
          }
        ]
      }
    ]
  },
  "requested_cart_actions": [
    {
      "kind": "remove_cart_line",
      "reason": "redemption_expired",
      "cart_line_to_remove": {
        "kind": "shopify",
        "id": "gid://shopify/CartLine/735a73a2-666f-4df2-91dc-540bc1b8b9ba",
        "merchandise_id": "gid://shopify/ProductVariant/1001",
        "attributes": [
          {
            "key": "<string>",
            "value": "<string>"
          }
        ]
      },
      "cart_redemption": {
        "id": "A7EB"
      }
    }
  ]
}

Initialize a headless session for the customer with the given merchant_id (the ID of the customer in your store or platform).

For convenience, the full program configuration, as returned by the Get Configuration endpoint, is also included in the response.

If you’re building your own headless web UI, you should generally call this once on each page load, or, for a mobile app, once per “session”, e.g. when the customer opens or resumes the app.

Compared to the read-only Get Customer endpoint, this endpoint can create and enroll customers, and will trigger any relevant rules.

  • if no matching customer exists in LoyaltyLion for the given merchant_id, a new customer will be created, potentially enrolled into the program, and returned
  • if a matching customer is found in LoyaltyLion, they may be enrolled and returned

Customers will be enrolled based on the program’s configuration. For example, if the program is configured to auto-enroll customers, they’ll become enrolled automatically when their session is initialized.

For both new and existing customers, program rules may be triggered for the customer. For example:

  • “join program” rule if the customer was just enrolled from this session
  • “pageview” rule if the channel is web and they’re viewing a relevant page
  • “download mobile app” rule if the channel is mobile

Authorizations

​
Authorization
string
header
required

An API key linked to a Program in LoyaltyLion, with a set of permissions (scopes). API keys can be created manually, or acquired through an OAuth2 flow. The API key should be provided as a Bearer token in the Authorization header

Path Parameters

​
site_id
number
required

Your LoyaltyLion Site ID. If a new customer is created from this API call, they'll be created in this Site, which is relevant for multi-site programs

​
merchant_id
string
required

The ID of the customer in your platform or ecommerce store.

For Shopify stores, you can pass either a GID or a regular numeric ID. If you do pass a GID you must encode it as a URL parameter, e.g. gid%3A%2F%2Fshopify%2FCustomer%2F1001

Minimum length: 1

Query Parameters

​
channel
enum<string>

The sales channel from which this request is made. Must be provided as this query parameter, or the X-LoyaltyLion-Channel header

Available options:
web,
pos,
mobile

Body

application/json

Body

The body is of type object.

Response

200
application/json

200

The response is of type object.