The Payments tag at apis.io/tags/payments/ is carried by 1,561 providers and 933 APIs. Its aggregate composite is 35.9, which places it in the emerging band, and it has not moved: trend flat, delta 0.0 against a previous composite of 35.9.
The interesting number is the ratio. 933 APIs to 1,561 providers — 60% propagation.
A tag that mostly survives the trip
Last week’s read of the Open-Source tag found 1,087 providers and only 210 APIs — a five-to-one inversion, because open source is a property of a company and rarely reaches the API. Payments does the opposite. Six APIs in ten inherit the tag from their provider, because taking money is a thing an API does, not a thing a company merely is.
The facet breakdown says the same:
| Facet | Value |
|---|---|
| Frequency | 81.7 |
| Quality lift | 38.4 |
| Cohesion | 33.7 |
| Breadth | 11.0 |
Breadth at 11.0 is the constraint. Payments appears constantly, but almost entirely inside financial services, commerce, and the platforms adjacent to them. It is a high-frequency, low-spread tag — the opposite of a horizontal concern like authentication.
Why 35.9 is lower than it feels
Payments feels like it should be a top-scoring tag. Every well-known name in it — Stripe, Adyen, Square, PayPal, Paystack, Airwallex — is exemplar or strong.
The aggregate is 35.9 because the tag also pulls in a very long tail. Scroll the membership list and you get 2C2P, 99Bill, AbacatePay, ACI Worldwide, Addi, and hundreds more: regional processors, single-market acquirers, and companies whose payments capability is a checkout page rather than a described API. Every one of them is legitimately tagged and most of them publish nothing machine-readable.
That is the honest shape of payments as an industry. A handful of global platforms with excellent contracts, and a very large number of local processors where integration still means a PDF, a sandbox credential, and a phone call.
Cohesion at 33.7
Cohesion measures whether the things wearing a tag resemble each other. At 33.7, payments is middling — and it should be, because “payments” spans card acquiring, bank transfers, payouts, wallets, crypto rails, tax, invoicing, and fraud scoring. Those are not one capability. They are a supply chain that happens to share a noun.
Anyone using this tag as a shortlist should treat it as a starting corpus, not an answer. Narrow by region and by function before comparing anything, because a Brazilian acquirer and a cross-border payout API have no overlap beyond the word.
Takeaway
1,561 providers, 933 APIs, 60% tag propagation, and a flat 35.9. Payments is a genuinely API-native capability — unlike open source, the tag survives the trip from company to contract — sitting on a long tail of regional processors that keeps the average well below what its leaders deserve.
Browse the tag at apis.io/tags/payments/.