Fiat on/off-ramp API

Five providers, all under /api/defi. Blazpay charges nothing here; each provider's own spread applies and the UI compares them.

Product page: buy / sell.

Unified quote comparison

Method	Path	Controller
POST	/defi/on-off-ramp-quotes	services/buy.js → buyQuotes

Queries every integrated ramp in parallel and returns the resulting crypto amount from each. Per-provider failures are caught and logged rather than failing the whole comparison — the user sees fewer options, not an error.

Chain and country maps live in bz-backend/utils/onRampConst.js (onRampChain, onrampCountries).

OnRamp.money

The India rail — INR via UPI, IMPS and bank transfer, with no international card needed.

Method	Path	Purpose
POST	/defi/onramp/quotes	Quote
GET	/defi/onramp/save-crypto	Admin — refresh the crypto catalogue into onRampCrypto
GET	/defi/onramp/save-fiat	Admin — refresh fiat types
GET	/defi/onramp/assign	Assign a reference for webhook correlation
POST	/defi/onramp/setWebhook	Register the webhook URL with OnRamp
POST	/defi/onramp/webhook	Receive status callbacks

SECRET_KEY_ONRAMP. Controller: onRampController.js.

Changelly (fiat)

Method	Path	Purpose
POST	/defi/changelly/quotes	Quote
POST	/defi/changelly/crypto-list	Currency list
POST	/defi/changelly/webhook-url	Register webhook
GET	/defi/changelly/save-crypto	Admin — refresh changellyCrypto
GET	/defi/changelly/save-fiat	Admin — refresh changellyFiat
GET	/defi/changelly/assign	Assign a crypto reference
GET	/defi/changelly/assign-fiat	Assign a fiat reference

CHANGELLY_PRIVATE_KEY / PRIVATE_KEY_CHANGELLY for request signing. Controller: changellyFiat.js.

Changelly's instant crypto-to-crypto endpoints are separate (POST /defi/changelly, POST /defi/changelly/transaction) and documented under provider proxies.

AlchemyPay

Method	Path	Purpose
POST	/defi/alchemy/quotes	Quote
POST	/defi/alchemy/sign	Sign a payload for AlchemyPay's checkout
GET	/defi/alchemy/save-crypto	Admin — refresh alchemyCrypto
GET	/defi/alchemy/save-fiat	Admin — refresh alchemyFiat
GET	/defi/alchemy/assign	Assign a crypto reference
GET	/defi/alchemy/assign-fiat	Assign a fiat reference
GET	/defi/alchemy/webhook	Status callback

SECRET_KEY_ALCHEMY. Controller: alchemyController.js.

Transak

Method	Path	Purpose
GET	/defi/transak	Currency list; also refreshes transacCrypto / transacFiat
GET	/defi/transak/assign	Assign a reference (transaction.controller.js → assignTokensTransac)

Controller: transak.js. The frontend also uses @transak/transak-sdk directly for the widget.

MoonPay

Method	Path	Purpose
GET	/defi/moonpay	Currency list

Controller: moonPay.js.

Patterns worth knowing

Reference assignment

Every provider needs a reference so its webhook can be correlated back to a Blazpay order. Hence the assign* endpoint pairs above. Without one, a completed purchase cannot be attributed.

Catalogue caching

Provider catalogues (which tokens on which chains, which fiat currencies) are cached in Mongo rather than queried live:

Collection	Refreshed by
alchemyCrypto, alchemyFiat	GET /defi/alchemy/save-crypto, /save-fiat
changellyCrypto, changellyFiat	GET /defi/changelly/save-crypto, /save-fiat
onRampCrypto	GET /defi/onramp/save-crypto
transacCrypto, transacFiat	GET /defi/transak

There is no refresh cron

A newly listed token on a provider does not appear in Blazpay until someone calls the corresponding save-* endpoint. "Provider X supports token Y but Blazpay does not offer it" is almost always a stale catalogue, not a missing integration.

These are GET requests that mutate

GET /defi/alchemy/save-crypto writes to the database. They are administrative endpoints with no auth. Do not infer safety from the verb — see conventions.

Order records

Orders are persisted in models/buySellOrders.js. The Blazpay-side record is created through POST /defi/order/create or POST /defi/order, and read with GET /defi/order/:walletAddress.

Currency coverage

20+ fiat currencies:

INR  USD  EUR  GBP  AED  TRY  MXN  VND  NGN  BRL
PEN  COP  CLP  PHP  IDR  KES  ZAR  THB  MYR  ARS

The emerging-market entries — VND, NGN, KES, IDR, PHP, COP, PEN, CLP — are the differentiated ones. Off-ramp coverage is narrower than on-ramp for several of these corridors.

In BlazAI

The BUY intent returns action buy_sell, rendered by swapAI/buy/BuyQuoteContainer. So a user can say "buy 10000 rupees of bitcoin" and get the same provider comparison inline. See intent catalogue.

Failure modes

Symptom	Cause
A provider missing from the comparison	Its quote call failed; errors are caught and logged per provider
A token the provider supports is not offered	Stale catalogue — call the relevant save-crypto endpoint
A completed purchase not reflected	Reference not assigned, or webhook not registered
KYC stuck	Provider-side. Blazpay holds no identity documents and cannot resolve it
Off-ramp unavailable for a currency	That provider does not support that direction for that corridor