marketplace ranking api // decisioning infrastructure

Marketplace ranking that balances
relevance and revenue.

The ranking layer between candidate generation and the listings a buyer sees. Gortex orders every search and browse surface and fills sponsored slots in one call, balancing relevance, take-rate, and supply fairness without a ranking team to run it.

request access → view the simulation

# 01 / the problem

Ranking a marketplace is a moving target, not a solved problem.

Every listing you show trades off three things at once: buyer relevance, the take-rate you earn, and whether supply stays healthy enough to keep sellers. The weights shift as inventory, seasonality, and seller mix change, so the team that ranks the marketplace keeps re-tuning it, on the request path, forever.

01 three objectives, one slot

Buyer relevance, monetization, and supply fairness pull in different directions, and every ranked position has to reconcile all three at once.

02 latency on every query

Ranking runs on the request path. Every added signal is latency you pay on every search and every browse page, for both sides of the market.

03 sponsored listings bolted on later

Sponsored placement gets built as a second auction, then reconciled with organic ranking by hand, release after release.

04 no record of why a listing ranked

When a seller disputes placement or a buyer complaint lands, there is often no trace of why a listing placed where it did.

# 02 / how it works

One endpoint ranks the listings and places sponsored slots in the same response.

You send a buyer, a surface, and the listings you already retrieved. Gortex returns the organic order and the sponsored placements together, weighted for relevance, take-rate, and supply fairness, inside one sub-200ms p99 budget, with a decision id you can audit later.

your retrieval

you gather the candidate listings for the query: products, services, or sellers.

gortex decides

rank the listings against your objectives and resolve sponsored slots, in one call.

your surface

render the ranked results with sponsored listings already placed and priced.

01 you keep retrieval

Gortex ranks the listings you bring. No data migration, no re-platforming.

02 ranking and monetization in one call

Organic order and sponsored slots resolve against each other, so a paid listing only takes a slot when the placement still serves the buyer and the supply mix.

03 every decision is traceable

Each response carries a decision id and a trace id. The reason a listing ranked is recorded, not reconstructed after a dispute.

04 seven typed sdks

Generated from one OpenAPI 3.1 spec, so contract drift across languages is mechanically impossible.

# 03 / the call

One request. Ranked listings and their sponsored slots.

POST /v1/decide
200 OK · 71ms
 // Rank a marketplace search and fill its sponsored slots.
$ curl api.gortex.ai/v1/decide \
  -H "Authorization: Bearer $GORTEX_KEY" \
  -d '{
    "recipient": { "id": "b_8120" },
    "context":   { "surface": "marketplace_search" },
    "items":     [ /* 200 candidate listings */ ]
  }'

{
  "ranked":      [ /* ordered listing IDs */ ],
  "sponsored":   [{ "slot": 2, "price": 0.58 }],
  "decision_id": "d_01HXZ3M",
  "trace_id":    "t_01HXZ3N"
} 

# 04 / questions

Marketplace ranking, answered plainly.

What is a marketplace ranking API?

An endpoint that takes the listings you retrieved for a search or browse query and returns them in the order a buyer should see them. Gortex places sponsored listings in the same response, so relevance ranking and monetization resolve together.

How does it balance buyer relevance against seller and supply health?

You pass the objectives that matter for the surface: buyer relevance, take-rate, and supply fairness. Gortex resolves them against one ranked order in a single call, so you tune the balance by policy instead of re-tuning a ranking stack.

How fast is a marketplace ranking call?

Ranking and sponsored placement resolve inside one sub-200ms p99 budget, on the request path, so you can call it on every search and every browse page.

# 05 / start

See a marketplace ranking decision, live.

The private beta is by invitation. Tell us the surface you rank and the objectives you balance, and we will get you a key.

request access → view the simulation read the anatomy read the guide

Marketplace ranking that balances relevance and revenue.