Payment Uat Unifiedpost OPG Transaction Initiation
★ Only Publicly Available OpenAPI DocumentPaymentsPayment Processingbearer2 EndpointsREST
For Agents
Generate payment initiation URLs for single and batch transactions through Unifiedpost's Online Payment Gateway, enabling merchants to collect payments via secure redirect links.
Use for: I need to create a payment link for a customer, I want to initiate a batch of payment requests, Generate a payment URL for a single transaction, Set up a payment redirect for a specific merchant
Not supported: Does not handle payment confirmation, refunds, reconciliation, or subscription management - use for payment URL generation and transaction initiation only.
Jentic publishes the only available OpenAPI specification for OPG Transaction Initiation, keeping it validated and agent-ready. The OPG (Online Payment Gateway) Transaction Initiation API from Unifiedpost enables merchants to create payment initiation URLs for single and batch transactions. It supports generating secure payment links that redirect consumers to complete payments, covering both individual item payments and multi-item batch processing through two dedicated endpoints.
Install Jentic One Beta
Connect the OPG Transaction Initiation to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the OPG Transaction Initiation, 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%2Fpayment.uat.unifiedpost.com%2Funifiedpost" | 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%2Fpayment.uat.unifiedpost.com%2Funifiedpost" | 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 OPG Transaction Initiation API.
Generate secure payment initiation URLs for individual transactions
Create batch payment initiation requests for multiple items in a single call
Support merchant-specific payment flows via configurable merchant IDs
Enable consumer-facing payment pages through redirect-based checkout
Use Cases
Patterns agents use OPG Transaction Initiation API for, with concrete tasks.
★ Single Payment Link Generation
Create a one-time payment URL that redirects the consumer to a secure payment page. The merchant provides the transaction amount and details, and the API returns a URL that can be sent via email, SMS, or embedded in an invoice. The consumer completes payment on the hosted page without the merchant handling card data directly.
Create a single payment initiation URL for merchant {merchant_id} with amount 50.00 EUR via POST /item/initiate/single/{merchant_id}
Batch Payment Initiation
Generate payment requests for multiple items or invoices in a single API call. The batch endpoint accepts an array of payment items each with their own amount and reference, returning individual payment URLs for each. This supports scenarios like monthly invoice runs where dozens of payment links need to be created simultaneously.
Submit a batch of 5 payment items to POST /item/initiate/{merchant_id} with individual amounts and references, and retrieve the generated payment URLs
AI Agent Payment Link Creation via Jentic
AI agents use Jentic to generate payment initiation URLs without managing API authentication or constructing merchant-specific request payloads manually. Jentic provides the operation schema so agents can create payment links for invoicing workflows or e-commerce checkouts with validated inputs.
Search Jentic for 'create a payment link', load the OPG operation schema, and execute it to generate a payment URL for a 75.00 EUR transaction
Key Endpoints
2 endpoints — jentic publishes the only available openapi specification for opg transaction initiation, keeping it validated and agent-ready.
METHOD
PATH
DESCRIPTION
POST
/item/initiate/single/{merchant_id}
Create a single payment initiation URL
POST
/item/initiate/{merchant_id}
Create batch payment initiation URLs
POST
/item/initiate/single/{merchant_id}
Create a single payment initiation URL
POST
/item/initiate/{merchant_id}
Create batch payment initiation URLs
Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
Wiring the Unifiedpost OPG API by hand means handling its bearer auth against the secured payment host and building transaction initiation payloads yourself. Through Jentic you install once, import the OPG Transaction Initiation API from the API Directory, store the token once, and your agent calls it.
Permission scoping
OPG puts the merchant id in the URL path (/item/initiate/single/{merchant_id}), so a rule can pin your agent to one merchant: it can initiate transactions for that merchant and nothing else. You choose the operations it may call, so no operation runs beyond the set you allow.
Credential isolation
Your Unifiedpost OPG bearer token is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.
Intent-based discovery
Agents search Jentic by intent such as 'generate a payment link for a merchant', and Jentic returns the matching OPG operation with its merchant id path parameter and payment item 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 API
Global payment platform with hosted checkout, payment links, and full lifecycle management
Choose Stripe when you need a complete payment solution with refunds, disputes, subscriptions, and global coverage rather than just payment URL generation.
FAQs
Specific to using OPG Transaction Initiation API through Jentic.
Why is there no official OpenAPI spec for OPG Transaction Initiation?
Unifiedpost does not publish an OpenAPI specification for the OPG API. Jentic generates and maintains this spec so that AI agents and developers can call OPG Transaction Initiation 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 OPG Transaction Initiation API use?
The OPG API uses Bearer token authentication. You include your merchant API token in the Authorization header. The secured base path indicates all requests require authentication. Through Jentic, the bearer token is stored in your Jentic One instance and injected into requests automatically.
Can I create payment links for multiple invoices at once?
Yes. The POST /item/initiate/{merchant_id} endpoint accepts a batch of payment items in a single request. Each item includes its own amount, currency, and reference. The API returns individual payment URLs for each item, enabling bulk invoice payment link generation in one call.
What is the difference between the single and batch endpoints?
POST /item/initiate/single/{merchant_id} creates one payment URL for a single transaction. POST /item/initiate/{merchant_id} accepts an array of items and generates multiple payment URLs in one request. Use the single endpoint for real-time checkout flows and the batch endpoint for invoice runs or scheduled billing.
How do I generate a payment link through Jentic?
Search Jentic for 'create a payment initiation URL' to find the POST /item/initiate/single/{merchant_id} operation. Jentic returns the input schema showing required fields like merchant_id, amount, and currency. Execute through Jentic and receive the payment URL ready to send to your customer. Install with pip install jentic.
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