APIs · shortlist
Free finance and payments APIs
Market data, currency exchange, accounting and payment endpoints you can call without a commercial contract. Bank and brokerage APIs are almost always gated; what is listed here is what is genuinely open.
How this list was ordered. There is no reliable popularity signal in the source registries, so entries are ranked by how completely the record is documented — a substantial description plus a documentation, repository or base URL — and then alphabetically. 59 apis in this scope clear the content bar; the top 24 are shown. A place here is not an endorsement or a paid slot.
Shortlisted entries
- 01
Account API
This API is used for the classic integration. If you are just starting your implementation, refer to our new integration guide instead. The Account API provides endpoints for managing account-related entities on your platform. These related entities include account holders, accounts, bank accounts, shareholders, and verification-related documents. The management operations include actions such as creation, retrieval, updating, and deletion of them. For more information, refer to our documentation. ## Authentication Your Adyen contact will provide your API credential and an API key. To connect to the API, add an X-API-Key header with the API key as the value, for example: curl -H "Content-Type: application/json" \ -H "X-API-Key: YOURAPIKEY" \ ... Alternatively, you can use the username and…
Payment auth: API Key
api.apis.guru/v2/specs/adyen.com/AccountService/6/openapi.json ↗
- 02
Adyen Balance Control API
The Balance Control API lets you transfer funds between merchant accounts that belong to the same legal entity and are under the same company account. ## Authentication To connect to the Balance Control API, you must authenticate your requests with an API key or basic auth username and password. To learn how you can generate these, see API credentials.Here is an example of authenticating a request with an API key: curl -H "X-API-Key: YourAPIkey" \ -H "Content-Type: application/json" \ ... Note that when going live, you need to generate API credentials to access the live endpoints. ## Versioning The Balance Control API supports versioning using a version suffix in the endpoint URL. This suffix has the following format: "vXX", where XX is the version number. For example: https://pal-test.ad…
Payment auth: API Key
api.apis.guru/v2/specs/adyen.com/BalanceControlService/1/openapi.json ↗
- 03
Adyen BinLookup API
The BIN Lookup API provides endpoints for retrieving information, such as cost estimates, and 3D Secure supported version based on a given BIN. ## Authentication You need an API credential to authenticate to the API. If using an API key, add an X-API-Key header with the API key as the value, for example: curl -H "Content-Type: application/json" \ -H "X-API-Key: YOURAPIKEY" \ ... Alternatively, you can use the username and password to connect to the API using basic authentication, for example: curl -U "ws@Company.YOURCOMPANYACCOUNT":"YOURBASICAUTHENTICATIONPASSWORD" \ -H "Content-Type: application/json" \ ... ## Versioning The BinLookup API supports versioning using a version suffix in the endpoint URL. This suffix has the following format: "vXX", where XX is the version number. For exampl…
Payment auth: API Key
api.apis.guru/v2/specs/adyen.com/BinLookupService/54/openapi.json ↗
- 04
Adyen Checkout API
Adyen Checkout API provides a simple and flexible way to initiate and authorise online payments. You can use the same integration for payments made with cards (including 3D Secure), mobile wallets, and local payment methods (for example, iDEAL and Sofort). This API reference provides information on available endpoints and how to interact with them. To learn more about the API, visit online payments documentation. ## Authentication Each request to Checkout API must be signed with an API key. For this, get your API key from your Customer Area, and set this key to the X-API-Key header value, for example: curl -H "Content-Type: application/json" \ -H "X-API-Key: YOURAPIKEY" \ ... ## Versioning Checkout API supports versioning using a version suffix in the endpoint URL. This suffix has the fol…
Payment auth: API Key
api.apis.guru/v2/specs/adyen.com/CheckoutService/70/openapi.json ↗
- 05
Adyen Data Protection API
Adyen Data Protection API provides a way for you to process Subject Erasure Requests as mandated in GDPR. Use our API to submit a request to delete shopper's data, including payment details and other related information (for example, delivery address or shopper email).## Authentication Each request to the Data Protection API must be signed with an API key. Get your API Key from your Customer Area, as described in How to get the API key. Then set this key to the X-API-Key header value, for example: curl -H "Content-Type: application/json" \ -H "X-API-Key: YourAPIkey" \ ... Note that when going live, you need to generate a new API Key to access the live endpoints. ## Versioning Data Protection Service API supports versioning using a version suffix in the endpoint URL. This suffix has the fo…
Payment auth: API Key
api.apis.guru/v2/specs/adyen.com/DataProtectionService/1/openapi.json ↗
- 06
Adyen Payment API
A set of API endpoints that allow you to initiate, settle, and modify payments on the Adyen payments platform. You can use the API to accept card payments (including One-Click and 3D Secure), bank transfers, ewallets, and many other payment methods. To learn more about the API, visit Classic integration. ## Authentication You need an API credential to authenticate to the API. If using an API key, add an X-API-Key header with the API key as the value, for example: curl -H "Content-Type: application/json" \ -H "X-API-Key: YOURAPIKEY" \ ... Alternatively, you can use the username and password to connect to the API using basic authentication, for example: curl -U "ws@Company.YOURCOMPANYACCOUNT":"YOURBASICAUTHENTICATIONPASSWORD" \ -H "Content-Type: application/json" \ ... ## Versioning Payment…
Payment auth: API Key
api.apis.guru/v2/specs/adyen.com/PaymentService/68/openapi.json ↗
- 07
Adyen Payout API
A set of API endpoints that allow you to store payout details, confirm, or decline a payout. For more information, refer to Online payouts. ## Authentication To use the Payout API, you need to have two API credentials: one for storing payout details and submitting payouts, and another one for confirming or declining payouts. If you don't have the required API credentials, contact our Support Team. Both of these API credentials must be authenticated with basic authentication.The following example shows how to authenticate your request when submitting a payout: curl -U "storePayout@Company.YOURCOMPANYACCOUNT":"YOURBASICAUTHENTICATIONPASSWORD" \ -H "Content-Type: application/json" \ ... ## Versioning Payments API supports versioning using a version suffix in the endpoint URL. This suffix has…
Payment auth: unknown
api.apis.guru/v2/specs/adyen.com/PayoutService/68/openapi.json ↗
- 08
Adyen Recurring API
The Recurring APIs allow you to manage and remove your tokens or saved payment details. Tokens should be created with validation during a payment request. For more information, refer to our Tokenization documentation. ## Authentication You need an API credential to authenticate to the API. If using an API key, add an X-API-Key header with the API key as the value, for example: curl -H "Content-Type: application/json" \ -H "X-API-Key: YOURAPIKEY" \ ... Alternatively, you can use the username and password to connect to the API using basic authentication, for example: curl -U "ws@Company.YOURCOMPANYACCOUNT":"YOURBASICAUTHENTICATIONPASSWORD" \ -H "Content-Type: application/json" \ ... ## Versioning Recurring API supports versioning using a version suffix in the endpoint URL. This suffix has t…
Payment auth: API Key
api.apis.guru/v2/specs/adyen.com/RecurringService/68/openapi.json ↗
- 09
Fire Financial Services Business API
The fire.com API allows you to deeply integrate Business Account features into your application or back-office systems. The API provides read access to your profile, accounts and transactions, event-driven notifications of activity on the account and payment initiation via batches. Each feature has its own HTTP endpoint and every endpoint has its own permission. The API exposes 3 main areas of functionality: financial functions, service information and service configuration. ## Financial Functions These functions provide access to your account details, transactions, payee accounts, payment initiation etc. ## Service Functions These provide information about the fees and limits applied to your account. ## Service configuration These provide information about your service configs - applicat…
Financial auth: Token
- 10
Fund API
This API is used for the classic integration. If you are just starting your implementation, refer to our new integration guide instead. The Fund API provides endpoints for managing the funds in the accounts on your platform. These management operations include, for example, the transfer of funds from one account to another, the payout of funds to an account holder, and the retrieval of balances in an account. For more information, refer to our documentation. ## Authentication Your Adyen contact will provide your API credential and an API key. To connect to the API, add an X-API-Key header with the API key as the value, for example: curl -H "Content-Type: application/json" \ -H "X-API-Key: YOURAPIKEY" \ ... Alternatively, you can use the username and password to connect to the API using ba…
Payment auth: API Key
api.apis.guru/v2/specs/adyen.com/FundService/6/openapi.json ↗
- 11
Hosted onboarding API
This API is used for the classic integration. If you are just starting your implementation, refer to our new integration guide instead. The Hosted onboarding API provides endpoints that you can use to generate links to Adyen-hosted pages, such as an onboarding page or a PCI compliance questionnaire. You can provide these links to your account holders so that they can complete their onboarding. ## Authentication Your Adyen contact will provide your API credential and an API key. To connect to the API, add an X-API-Key header with the API key as the value, for example: curl -H "Content-Type: application/json" \ -H "X-API-Key: YOURAPIKEY" \ ... Alternatively, you can use the username and password to connect to the API using basic authentication. For example: curl -U "ws@MarketPlace.YOURPLATF…
Payment auth: API Key
api.apis.guru/v2/specs/adyen.com/HopService/6/openapi.json ↗
- 12
Legal Entity Management API
The Legal Entity Management API enables you to manage legal entities that contain information required for verification. ## Authentication To connect to the Legal Entity Management API, you must use the basic authentication credentials of your web service user. If you don't have one, contact the Adyen Support Team. Use the web service user credentials to authenticate your request, for example: curl -U "ws123456@Scope.BalancePlatformYourBalancePlatform":"YourWsPassword" \ -H "Content-Type: application/json" \ ... Note that when going live, you need to generate new web service user credentials to access the live endpoints. ## Versioning The Legal Entity Management API supports versioning of its endpoints through a version suffix in the endpoint URL. This suffix has the following format: "vX…
Payment auth: unknown
api.apis.guru/v2/specs/adyen.com/LegalEntityService/3/openapi.json ↗
- 13
Notification Configuration API
This API is used for the classic integration. If you are just starting your implementation, refer to our new integration guide instead. The Notification Configuration API provides endpoints for setting up and testing notifications that inform you of events on your platform, for example when a verification check or a payout has been completed. For more information, refer to our documentation. ## Authentication Your Adyen contact will provide your API credential and an API key. To connect to the API, add an X-API-Key header with the API key as the value, for example: curl -H "Content-Type: application/json" \ -H "X-API-Key: YOURAPIKEY" \ ... Alternatively, you can use the username and password to connect to the API using basic authentication. For example: curl -U "ws@MarketPlace.YOURPLATFOR…
Payment auth: API Key
api.apis.guru/v2/specs/adyen.com/NotificationConfigurationService/6/openapi.json ↗
- 14
Paylocity API
For general questions and support of the API, contact: webservices@paylocity.com # Overview Paylocity Web Services API is an externally facing RESTful Internet protocol. The Paylocity API uses HTTP verbs and a RESTful endpoint structure. OAuth 2.0 is used as the API Authorization framework. Request and response payloads are formatted as JSON. Paylocity supports v1 and v2 versions of its API endpoints. v1, while supported, won't be enhanced with additional functionality. For direct link to v1 documentation, please click here. For additional resources regarding v1/v2 differences and conversion path, please contact webservices@paylocity.com. ##### Setup Paylocity will provide the secure client credentials and set up the scope (type of requests and allowed company numbers). You will receive t…
Financial auth: OAuth
- 15
Transfers API
The Transfers API provides endpoints that you can use to get information about all your transactions, move funds within your balance platform or send funds from your balance platform to a transfer instrument. ## Authentication Your Adyen contact will provide your API credential and an API key. To connect to the API, add an X-API-Key header with the API key as the value, for example: curl -H "Content-Type: application/json" \ -H "X-API-Key: YOURAPIKEY" \ ... Alternatively, you can use the username and password to connect to the API using basic authentication. For example: curl -H "Content-Type: application/json" \ -U "ws@BalancePlatform.YOURBALANCEPLATFORM":"YOURWSPASSWORD" \ ... ## Roles and permissions To use the Transfers API, you need an additional role for your API credential. Transfe…
Payment auth: API Key
api.apis.guru/v2/specs/adyen.com/TransferService/3/openapi.json ↗
- 16
Configuration API
The Configuration API enables you to create a platform where you can onboard your users as account holders and create balance accounts, cards, and business accounts. ## Authentication Your Adyen contact will provide your API credential and an API key. To connect to the API, add an X-API-Key header with the API key as the value, for example: curl -H "Content-Type: application/json" \ -H "X-API-Key: YOURAPIKEY" \ ... Alternatively, you can use the username and password to connect to the API using basic authentication. For example: curl -H "Content-Type: application/json" \ -U "ws@BalancePlatform.YOURBALANCEPLATFORM":"YOURWSPASSWORD" \ ... ## Versioning The Configuration API supports versioning using a version suffix in the endpoint URL. This suffix has the following format: "vXX", where XX…
Payment auth: API Key
api.apis.guru/v2/specs/adyen.com/BalancePlatformService/2/openapi.json ↗
- 17
NOWPayments API
NOWPayments is a non-custodial cryptocurrency payment processing platform. Accept payments in a wide range of cryptos and get them instantly converted into a coin of your choice and sent to your wallet. Keeping it simple – no excess. # Sandbox Before production usage, you can test our API using the Sandbox. Details can be found here # Authentication To use the NOWPayments API you should do the following: Sign up at nowpayments.io Specify your outcome wallet Generate an API key # Standard e-commerce flow for NOWPayments API: 1. API - Check API availability with the "GET API status" method. If required, check the list of available payment currencies with the "GET available currencies" method. 2. UI - Ask a customer to select item/items for purchase to determine the total sum; 3. UI - Ask a…
Financial auth: API Key
- 18
Portfolio Optimizer
Portfolio Optimizer is a Web API to analyze and optimize investment portfolios (collection of financial assets such as stocks, bonds, ETFs, crypto-currencies) using modern portfolio theory algorithms (mean-variance, VaR, etc.). # API General Information Portfolio Optimizer is based on REST for easy integration, uses JSON for the exchange of data and uses a standard HTTP verb (POST) to represent the action(s). Portfolio Optimizer is also as secured as a Web API could be: 256-bit HTTPS Encryption No usage of cookies No usage of personal data ## API Headers The following HTTP header(s) are required when calling Portfolio Optimizer endpoints: Content-type: application/json This header specifies that the data provided in input to the endpoint is in JSON format The following HTTP header(s) are…
Financial auth: API Key
api.apis.guru/v2/specs/portfoliooptimizer.io/1.0.9/openapi.json ↗
- 19
POS Terminal Management API
This API provides endpoints for managing your point-of-sale (POS) payment terminals. You can use the API to obtain information about a specific terminal, retrieve overviews of your terminals and stores, and assign terminals to a merchant account or store. For more information, refer to Assign terminals. ## Authentication Each request to the Terminal Management API must be signed with an API key. For this, obtain an API Key from your Customer Area, as described in How to get the API key. Then set this key to the X-API-Key header value, for example: curl -H "Content-Type: application/json" \ -H "X-API-Key: YourAPIkey" \ ... Note that when going live, you need to generate new web service user credentials to access the live endpoints. ## Versioning Terminal Management API supports versioning…
Payment auth: API Key
api.apis.guru/v2/specs/adyen.com/TfmAPIService/1/openapi.json ↗
- 20
Budgea API Documentation
Budgea Development Guides Welcome to Budgea's documentation. This documentation is intended to get you up-and-running with our APIs and advise on the implementation of some regulatory aspects of your application, following the DSP2's guidelines. ## Getting Started IMPORTANT Depending on your status with regard of the DSP2 regulation, agent or partner, you may call our APIs or simply use our Webview and callbacks to get the financial data of your users. As an agent, you are allowed to call directly our APIs and implement your own form to get the user's credentials. As a partner, you cannot manipulate the credentials, and have to delegate this step to us through our webview. The sections below will document how to use our APIs, make sure you have the agent status to do so. For the partner…
Financial auth: OAuth
- 21
Rebilly REST API
Introduction The Rebilly API is built on HTTP. Our API is RESTful. It has predictable resource URLs. It returns HTTP response codes to indicate errors. It also accepts and returns JSON in the HTTP body. You can use your favorite HTTP/REST library for your programming language to use Rebilly's API, or you can use one of our SDKs (currently available in PHP and Javascript). We have other APIs that are also available. Every action from our app is supported by an API which is documented and available for use so that you may automate any workflows necessary. This document contains the most commonly integrated resources. # Authentication When you sign up for an account, you are given your first secret API key. You can generate additional API keys, and delete API keys (as you may need to rotat…
Payment auth: API Key
- 22
Account and Transaction API Specification - UK
Functionality at a glance The NBG "UK OPB - Account and Transaction v3.1.5" API follows the UK Open Banking Specification v3.1.5 This Account and Transaction API Specification describes the flows and payloads for retrieving a list of accounts and their transactions. The API endpoints described here allow a AISP to: Create the Consent with the appropriate permissions in order to be able to access the API Endpoints Retrieve the list of accounts Retrieve an account's details Retrieve an account's balances Retrieve an account's transactions Retrieve an account's beneficiaries Retrieve an account's standing orders Retrieve an account's party Retrieve an account's scheduled payments Retrieve an account's statements ## Quick Getting Started 1. Login/Register to the NBG Technology HUB 2. Go to…
Financial auth: OAuth
- 23
Swiss NextGen Banking API-Framework
Summary The Swiss NextGen API is based on the NextGenPSD2 Framework Version 1.3.4 of the Berlin Group which offers a modern, open, harmonised and interoperable set of Application Programming Interfaces (APIs) as the safest and most efficient way to provide data securely. The NextGen Framework reduces XS2A complexity and costs, addresses the problem of multiple competing standards in Europe and, aligned with the goals of the Euro Retail Payments Board, enables European banking customers to benefit from innovative products and services ('Banking as a Service') by granting TPPs safe and secure (authenticated and authorised) access to their bank accounts and financial data. The Swiss edtion refines the message formats specific to Switzerland and defines some matching examples. The possible…
Financial auth: OAuth
- 24
Frankie Financial API
This API allows developers to integrate the Frankie Financial Compliance Utility into their applications. The API allows: - Checking name, address, date of birth against national databases - Validating Australian driver's licences, passports, medicare, visas and other Australian national ID documents - Validating Australian electricity bills - Validating NZ driver's licences - Validating Chinese bank cards and national ID card - Validating International passports and national ID documents - PEP, Sanctions, Watchlist and adverse media checking - Australian visa checks - Fraud list and fraud background checks - ID validation and selfie check comparisons. ------ Industry specific services - Comparing Australian electricity retailers for a better deal. ------ KYB specific services - Qu…
Financial auth: API Key
api.apis.guru/v2/specs/frankiefinancial.io/1.5.3/swagger.json ↗
Snapshot 2026-09-18. Fields shown are what the source registry stated, not a live probe — check the linked documentation before integrating. See the methodology.