You can't review a provider you haven't paid
Every review on Onlist requires at least one billed API call with that provider. How the payment gate works, what shows next to each review, and what it still cannot fix.
Reviews on infrastructure products are usually the least trustworthy thing on the page. Writing one costs nothing, so they attract everyone whose interest is not using the product: the vendor's own team, competitors, accounts with grudges. On an AI API marketplace the stakes are higher than for a restaurant, because the buyer is choosing who sits between their application and their users.
Onlist's answer is one hard rule: you cannot review a provider you have not paid. This post documents how the rule works, what we display next to each review, and what the rule still does not fix.
The gate is a ledger query, not a heuristic
To review a provider you need at least one billed API call settled against that provider. Not an account, not a bookmark, not a test request: a row in the settlement ledger that moved money from your wallet toward that provider. The check runs inside the same transaction that writes the review. Without the settlement row the API returns 403, and the review form does not render at all; what you see instead is a single sentence telling you a billed call is required first.
There is no minimum spend. One billed call qualifies, because the point is not to prove you are a big customer. The point is that every review is attached to a real commercial relationship.
You also get exactly one review per provider. Submitting again overwrites your previous one; the original date is kept and an edited note is shown. However strongly you feel, there is no path to volume.
What shows up next to your words
Each review carries three things beside the stars and the comment: a masked username, cumulative spend with that provider, and a call-count bucket (10+, 100+, 1,000+). Spend displays as whole dollars and caps at "$100+".
The coarseness is deliberate. Exact figures like "21,028 calls, $8.05" are a fingerprint: a seller could line them up against their own books and identify the reviewer. Rounded buckets keep the useful signal (this person genuinely used the service, and roughly this much) while destroying the fingerprint. Your own reviews page shows your own numbers precisely; everyone else sees the buckets.
The average is just an average
A provider's score is the arithmetic mean of its visible reviews. No Bayesian smoothing, no decay curves, no secret weighting.
We originally shipped a Bayesian prior, the textbook defense against small-sample rating abuse. We removed it. With the payment gate already limiting fake volume, the prior's main visible effect was to punish small providers: one honest five-star review displayed as 3.75 stars. That misleads buyers and demoralizes exactly the new sellers a marketplace needs most.
Ratings also feed routing. The scoring post covers the full trust model; the short version is that objective fulfillment comes first, and ratings act as a tiebreaker among providers in similar standing. A provider with no reviews routes on a neutral default until real ones arrive. Reviews are not decoration here. A bad rating costs a seller traffic.
What this does not fix
A provider can still pay itself. Nothing stops a seller from running API calls through their own storefront and leaving a five-star review from the buying account. The gate turns that from free into a costed action, since every self-directed call pays platform commission, but a deterrent is not a wall. The rating tooltip on model pages reads "For reference only, may be manipulated", and that wording is deliberate. We would rather undersell the signal than pretend it is tamper-proof.
Two more honest limits. Sellers cannot reply to reviews yet, so a provider facing an unfair one has no public right of reply beyond their support channel. And moderation is manual: a review that breaks the rules is hidden by an admin, at which point it drops out of both the public list and the average.
The rule does not make reviews perfect. It makes them expensive to fake: every review you read on Onlist was written by someone who put their own money on this provider, and the page shows you roughly how much.