Nuapay TPP API Specification
★ Only Publicly Available OpenAPI DocumentPaymentsPayment ProcessingapiKey, oauth212 EndpointsREST
For Agents
Initiate PSD2 open-banking payments and refunds, browse supported banks, and query payment status across the Nuapay TPP network.
Use for: Initiate a pay-by-bank payment for a customer, List all banks available for open banking initiation, Get the status of a Nuapay payment by ID, Retrieve the full event history of an open-banking payment
Not supported: Does not handle card processing, KYC onboarding, or accounting reconciliation - use for PSD2 open-banking payment initiation and refunds only.
Jentic publishes the only available OpenAPI specification for Nuapay TPP API Specification, keeping it validated and agent-ready. Nuapay is a regulated PSD2 third-party provider that initiates open-banking payments directly from a payer's bank account across the UK and EU. The TPP API exposes payment initiation, refund, payment history, and bank discovery endpoints for merchants and partner integrators that want to bypass card rails. It is used by SaaS billing, e-commerce checkouts, and B2B collections where Pay-by-Bank is preferred over card networks.
Install Jentic One Beta
Connect the Nuapay TPP API Specification to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Nuapay TPP API Specification, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
1
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fnuapay.com%2Fnuapay" | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fnuapay.com%2Fnuapay" | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with Nuapay TPP API Specification API.
Initiate a Pay-by-Bank payment from a payer's bank account
Retrieve a payment record and its current open-banking status
List all payments created by a merchant or partner
Retry a failed or expired payment initiation
Refund a previously settled open-banking payment
Browse supported bank families and individual banks for payer selection
Inspect the event history of a specific payment for audit and reconciliation
Use Cases
Patterns agents use Nuapay TPP API Specification API for, with concrete tasks.
★ Pay-by-Bank Checkout
Merchants offer Pay-by-Bank as a checkout option to avoid card processing fees. The flow starts with POST /payments, the customer authenticates at their bank, and the merchant polls GET /payments/{paymentId} until the open-banking status confirms settlement. Nuapay handles the regulated AISP and PISP flows in the background.
Call POST /payments with the order amount and payer bank, then poll GET /payments/{paymentId} until the status reaches settled
Bank Selection and Discovery
Checkout pages render a bank picker driven by GET /bankfamilies and GET /banks so the payer can choose their institution before authorisation. The endpoints return logos, identifiers, and payment-rail support that the front end uses to filter selectable banks.
Call GET /bankfamilies, then GET /banks to populate a bank picker for an open-banking checkout
Refunds and Payment History
Operations teams reconcile open-banking flows by calling GET /payments/{paymentId}/history for the full event timeline and POST /payments/{paymentId}/refunds to push money back to the payer. Refunds and history are scoped to a specific payment ID to preserve audit trails.
Call POST /payments/{paymentId}/refunds with the refund amount, then GET /payments/{paymentId}/refunds/{refundId} to confirm status
Agent-Driven Open-Banking Workflow
An AI agent initiates Pay-by-Bank checkouts on behalf of a finance team, polls payment status, and triggers refunds when an order is cancelled. Through Jentic the agent searches for 'initiate open banking payment', loads the POST /payments schema, and executes without learning Nuapay's TPP-specific OAuth flow.
Search Jentic for 'initiate open banking payment', load the schema for POST /payments, and execute with the merchant ID and amount
Key Endpoints
12 endpoints — jentic publishes the only available openapi specification for nuapay tpp api specification, keeping it validated and agent-ready.
METHOD
PATH
DESCRIPTION
POST
/payments
Create an open-banking payment
GET
/payments/{paymentId}
Retrieve a payment by ID
PATCH
/payments/{paymentId}
Retry a payment
GET
/payments/{paymentId}/history
Retrieve payment event history
POST
/payments/{paymentId}/refunds
Refund a payment
GET
/bankfamilies
List bank families
GET
/banks
List supported banks
POST
/payments
Create an open-banking payment
GET
/payments/{paymentId}
Retrieve a payment by ID
PATCH
/payments/{paymentId}
Retry a payment
GET
/payments/{paymentId}/history
Retrieve payment event history
POST
/payments/{paymentId}/refunds
Refund a payment
GET
/bankfamilies
List bank families
GET
/banks
List supported banks
Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
Wiring the Nuapay TPP API by hand means handling both HTTP basic keys and an OAuth 2.0 password flow, carrying the right open-banking scopes into calls to api.nuapay.com/tpp, and mapping payment initiation, refunds, and bank lookups yourself. Through Jentic you install once, import the Nuapay TPP API from the API Directory, store the credentials once, and your agent calls it.
Permission scoping
Nuapay puts the payment id in the URL path (/payments/{paymentId}), so a rule can pin your agent to one payment: it can read that payment's status and history and nothing else. You choose the operations it may call, so initiating payments and posting refunds are not included unless you add them.
Credential isolation
Your Nuapay merchant and partner credentials, including the API keys and OAuth2 client secrets, are stored once, encrypted, by your own Jentic One instance and injected at execution time. They never enter the agent's prompt, logs, or context.
Intent-based discovery
Agents search Jentic by intent such as 'initiate an open banking payment' or 'refund a pay-by-bank transaction', and Jentic returns the matching Nuapay operation with its input schema so the agent calls the right endpoint without browsing the reference docs.
Related APIs
Alternatives and complements available in the Jentic catalogue.
Alternative
Stripe
Card-first payment processor with optional bank-debit rails
Choose Stripe for card-led checkout with global coverage; choose Nuapay when Pay-by-Bank is the primary rail and TPP licensing is required.
FAQs
Specific to using Nuapay TPP API Specification API through Jentic.
Why is there no official OpenAPI spec for Nuapay TPP API Specification?
Nuapay does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call Nuapay TPP API Specification via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.
What authentication does the Nuapay TPP API use?
The spec defines four schemes: MerchantApiKey and PartnerApiKey for HTTP key auth, plus MerchantOAuth2 and PartnerOAuth2 client-credentials flows. Through Jentic the appropriate credential is stored in the vault and injected at execution, so the agent never holds the raw key or token.
Can I retry a payment that failed at the bank?
Yes. PATCH /payments/{paymentId} retries a payment whose initiation expired or failed before the payer authenticated. Use this rather than creating a brand-new payment so the audit trail remains continuous.
How do I refund an open-banking payment through Jentic?
Search Jentic for 'refund open banking payment', load the schema for POST /payments/{paymentId}/refunds, and execute with the refund amount. Jentic injects the merchant credential and returns the created refund record.
What are the rate limits for the Nuapay TPP API?
The OpenAPI spec does not declare explicit rate limits. Nuapay applies regulated TPP limits and merchant-tier quotas in production; check your Nuapay dashboard or contact your account manager for the limits attached to your client ID.
How do I show a bank picker on my checkout?
Call GET /bankfamilies to list grouped institutions, then GET /banks to render individual selectable banks with logos and identifiers. Filter by country and the payment rails the bank supports before showing the picker.
Can I limit what my agent is allowed to do with the Nuapay TPP API?
Yes. Jentic One is self-hosted, so your own rules decide which operations and credentials the agent may use: because Nuapay puts the payment id in the URL path (/payments/{paymentId}), a rule can pin the agent to a single payment and let it read only that payment's status and history. You choose the operations it may call, so initiating payments and posting refunds are excluded unless you explicitly add them.
GET STARTED