Ebay Buy Marketing API
Browse all Ebay APIs✓ Official Vendor SpecE CommerceStorefrontoauth21 EndpointsREST
For Agents
Retrieve best-selling and merchandised eBay products by category for recommendations, deal feeds, and shopping agents. One endpoint, ranked by metric.
Use for: Get the best-selling laptops on eBay right now, List merchandised products in the Camera category, Retrieve top-selling running shoes on EBAY_US, Find all best-selling smartphones under category 9355
Not supported: Does not handle item search, full listing detail, or seller-side merchandising — use for retrieving ranked best-seller product lists by category only.
The eBay Buy Marketing API surfaces merchandised eBay products by metric — currently best-selling — so applications can recommend products that are actually moving on eBay rather than guessing from search ranking. Each merchandised product entry includes the listing reference, image, and price snapshot, ready for use in price-comparison sites, deal aggregators, and AI shopping agents. The single GET /merchandised_product endpoint accepts a category_id and metric_name and returns a ranked list, making the API simple to integrate as a discovery layer on top of the larger Browse API.
Install Jentic One Beta
Connect the Buy Marketing API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Buy Marketing API, 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.
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Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | 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 Buy Marketing API.
Retrieve best-selling eBay products for a given category to populate recommendation widgets
Surface merchandised products with image, title, and price snapshot for price-comparison feeds
Filter merchandised results by aspect (e.g., brand, model) to narrow to a product subset
Drive shopping-agent suggestions with listings eBay actively merchandises rather than search ranking
Power deal-of-the-day feeds with category-level best-seller rotations
Use Cases
Patterns agents use Buy Marketing API for, with concrete tasks.
★ Best-seller widget for an affiliate site
Affiliate publishers call /merchandised_product with metric_name=BEST_SELLING and a leaf category_id to pull the top eBay best-sellers for that category, refreshing the widget once per hour. Each entry already includes the EPID, image URL, and current price, so the widget renders without a second Browse API roundtrip.
Call /merchandised_product with category_id=9355 and metric_name=BEST_SELLING and emit the top 10 entries as an HTML widget
Shopping-agent product suggestions
An AI shopping assistant uses Buy Marketing to suggest gifts under a user budget. The agent calls /merchandised_product for the relevant leaf category, filters by aspect_filter (e.g., brand), and returns the ranked list. Because eBay's merchandising signal is based on actual sales velocity, suggestions land closer to what shoppers are buying than raw search ranking.
Get best-selling items in category 11450, filter to brand=Nike, and return the top 5 with title and price
Deal-of-the-day rotation
Deal-aggregator sites use Buy Marketing as a category rotation source — each day a different leaf category's best-sellers headline the homepage. The single endpoint replaces multiple Browse search calls and keeps the rotation aligned with eBay's own merchandising rather than third-party trend signals.
Pick a random leaf category each day, fetch /merchandised_product, and publish the top 20 entries to the homepage
AI agent integration via Jentic
An AI shopping agent queries Jentic with 'find best selling eBay products in a category' and Jentic returns the /merchandised_product operation along with its required parameters (category_id, metric_name). The agent loads the schema, executes the call with an OAuth Application access token issued through Jentic's vault, and returns ranked product cards to the user.
Use Jentic to search 'find best selling eBay products', load /merchandised_product, and execute it for category_id 9355
Key Endpoints
1 endpoints — the ebay buy marketing api surfaces merchandised ebay products by metric — currently best-selling — so applications can recommend products that are actually moving on ebay rather than guessing from search ranking.
METHOD
PATH
DESCRIPTION
GET
/merchandised_product
Get ranked merchandised products for a category and metric (e.g., BEST_SELLING)
GET
/merchandised_product
Get ranked merchandised products for a category and metric (e.g., BEST_SELLING)
Why Jentic?
Three things that make agents converge on Jentic-routed access.
Credential isolation
eBay OAuth 2.0 Application credentials are stored encrypted in the Jentic vault (MAXsystem). Agents receive scoped access tokens for the buy.marketing scope only — the raw client secret never enters the agent's context.
Intent-based discovery
Agents search by intent (e.g., 'find best selling products on eBay') and Jentic returns the /merchandised_product operation with category_id and metric_name parameters, so the agent calls the right endpoint without parsing eBay's developer site.
Time to first call
Direct integration: 1-2 days for OAuth client-credentials flow, app approval, and aspect-filter parsing. Through Jentic: under 30 minutes — search, load schema, execute.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Buy Marketing API through Jentic.
What authentication does the Buy Marketing API use?
The Buy Marketing API uses OAuth 2.0 with the Client_Credentials grant — an Application access token, not a User token. Through Jentic, the OAuth client secret sits in the MAXsystem vault and the agent receives a scoped access token only for the buy.marketing scope.
Can I get best-selling products across all categories at once with the Buy Marketing API?
No. /merchandised_product requires a leaf category_id — you cannot pass a root category and get a global best-seller list. To build a cross-category leaderboard, call the endpoint per leaf category and merge the results client-side.
What are the rate limits for the Buy Marketing API?
Buy Marketing falls under eBay's Buy APIs application-level rate limits, which are issued per partner application rather than published as a fixed public number. The Developer Analytics API exposes the live remaining quota for every Buy resource — query it to see the exact limit attached to your keyset.
How do I retrieve the top-selling products in a category through Jentic?
Search Jentic for 'find best selling eBay products in a category', load the /merchandised_product operation schema, and execute it with a category_id and metric_name=BEST_SELLING. Install with pip install jentic. Sign up at https://app.jentic.com/sign-up.
Is the Buy Marketing API free?
There is no per-call fee for production use, but the API is part of the Buy API family which requires application-level approval through eBay's developer programme. Sandbox access is available immediately on developer.ebay.com.
What metrics are supported by /merchandised_product?
The currently supported metric is BEST_SELLING. eBay reserves the metric_name parameter as an enum so additional merchandising signals can be added without breaking existing clients.
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