Migrating from Legacy Coupon Server

Why migrate

LE 2025 replaces the legacy coupon/voucher fields with a single rule engine that supports more discount types, real-time limits and stackability, and gamification on top of the same engine. Moving your integration unlocks these without changing your overall POS-led architecture if you stay on Coupon Server mode.

What changes for your team

• One rule engine instead of flat coupon fields — more promotion types (BOGO, tiered quantity, combo price, strikethrough, bundles) become available without new integration work per type.
• A campaign catalog (GET /discounts) replaces single-voucher validation as the main read call.
• Interpreting rule_conditions / rule_application / rule_effects (JSON) replaces reading flat coupon fields — this is the main development effort.
• Voucher lifecycle actions (select, deselect, freeze, unfreeze, print, rollback) stay available. For New Engine Coupon Server amount confirmation, prefer POST /discounts/redeem over POST /vouchers/redeem — see Vouchers redeem vs Discounts redeem.
• Customer custom fields (custom1–custom11, custom1f–custom8f) are replaced by the attributes object — a data model change, not a promo engine change.

Choose your target model

Before mapping endpoints, confirm the target integration model with the client:

Model	Who calculates the final price	Guide
New Engine Promo Engine	Loyal Guru	New Engine Promo Engine
New Engine Coupon Server	POS / external system (same responsibility split as legacy)	New Engine Coupon Server

This guide assumes New Engine Coupon Server, since it keeps the same responsibility split as the legacy flow — the POS keeps calculating the final price.

Endpoint migration table

Legacy endpoint	New Engine Coupon Server	What changes
(no equivalent — legacy has no campaign catalog)	GET /discounts (+ customer_id/customer_code, location_id/location_code)	New: full campaign catalog with rule JSON, not a single voucher lookup
GET /vouchers/{code} + customer_id + location_id (validate)	GET /vouchers/{code} (same call) + GET /discounts for campaign context	Voucher validation call is unchanged; campaign/eligibility detail now comes from GET /discounts, not flat coupon fields
GET /customers/{id}/vouchers/selected	GET /discounts?customer_id=&selected=true	Dedicated endpoint replaced by a filter on the catalog endpoint
POST /vouchers/{code}/select / PUT /vouchers/select	Same	No change (shared voucher entity)
POST /vouchers/{code}/deselect / PUT /vouchers/deselect	Same	No change
POST /vouchers/{code}/freeze / POST /vouchers/{code}/unfreeze	Same	No change
POST /vouchers/redeem	Prefer POST /discounts/redeem for New Engine Coupon Server amount confirmation; keep POST /vouchers/redeem only for Legacy Coupon Server voucher-lifecycle-only flows	See Vouchers redeem vs Discounts redeem. Do not call both for the same confirmation
POST /vouchers/rollback	Same	No change
POST /vouchers/print	Same	No change
custom1–custom11 / custom1f–custom8f on Customer	attributes object	Data model change, not an endpoint change — see Custom fields → Attributes

Interpreting GET /discounts

This is the main development effort in the migration. See Reading and interpreting GET endpoints and the field-by-field reference in Reading from GET. rule_effects — with 6 effect types and 3 distribution modes — is typically the most complex part to replicate locally.

Implementation checklist

• Confirm target model (Promo Engine vs Coupon Server) with the client.
• Replace single-voucher validation reads with GET /discounts catalog reads, keeping GET /vouchers/{code} for final code validation.
• Implement rule_conditions / rule_application / rule_effects parsing.
• Confirm select, deselect, freeze, unfreeze, rollback, and print calls in the client's codebase do not need changes.
• For New Engine Coupon Server amount confirmation, switch usage confirmation to POST /discounts/redeem and stop calling POST /vouchers/redeem for the same confirmation — see Vouchers redeem vs Discounts redeem.
• Migrate any customN / customNf reads or writes on Customer to attributes.
• Re-test voucher print ordering and redemption/rollback error handling against the new catalog-based eligibility.

Troubleshooting

Symptom	What to check
A campaign that existed in legacy is missing from GET /discounts	Confirm it was recreated as a discount campaign in LE 2025 — legacy coupons are not auto-migrated.
POS discount amount differs after migration	Confirm rule_effects interpretation matches the effect type (percentage, direct_value, ratio, strikethrough, combo_price, formula) and its distribution.
Custom field values missing after migration	Confirm the company's attributes JSON Schema is configured and that the property name and case match exactly.