Ranked by the provider's API Evangelist rating — the Kin Score is scored per provider, not per API, so every API of a provider shares its band. How the rating works →

Exemplar 8 Complete, well-documented, and agent-ready

Cloudflare Memberships APIThe Memberships API from Cloudflare — 2 operation(s) for memberships.81.3 AfterShip Memberships APIThe Memberships API from AfterShip — 2 operation(s) for memberships.78.6 Close Memberships APIThe memberships API from Close — 3 operation(s) for memberships.75.8 Confluence Group API**[WARNING](https://support.atlassian.com/user-management/docs/create-and-update-groups/) The standard Atla...70.6 Mapp Marketing Cloud Membership APIThe Membership API from Mapp Marketing Cloud — 16 operation(s) for membership.70.4 Hint Health Membership APIThe Membership API from Hint Health — 6 operation(s) for membership.69.5 Webex Memberships APIThe Memberships API from Webex — 2 operation(s) for memberships.68.6 Bonitasoft Membership APIManage membership of users. There is a membership when a user belongs to a group and a role. Use this resou...66.8

Strong 11 Solid coverage with minor gaps

Commerce Layer Memberships APIresource type65.6 Amazon Clean Rooms Memberships APIOperations for managing collaboration memberships65.2 Eclipse Working Groups APIREST API for Eclipse working groups and special interest groups — participation levels, resources, particip...64.1 PixieBrix Memberships APIThe memberships API from PixieBrix — 1 operation(s) for memberships.62.2 NationBuilder Memberships APIA membership is a way to organize supporters and provide additional benefits based on actions they've taken...61.7 ServiceTitan Memberships APIManage membership types, customer memberships, membership invoice templates, recurring service types, and r...59.8 Amazon Web Services Membership APIThe Membership API from Amazon Web Services — 2 operation(s) for membership.59.4 Amazon Web Services Memberships APIThe Memberships API from Amazon Web Services — 14 operation(s) for memberships.59.4 Griffin Memberships APIMemberships represents the relationship between a [user](#tag/Users) and an [organization](#tag/Organizatio...58.5 Fintecture Memberships APIThe Memberships API from Fintecture — 2 operation(s) for memberships.55.1 Automattic Memberships APIThe memberships API from Automattic — 10 operation(s) for memberships.54.4

Developing 22 Usable, with meaningful gaps to close

Hang Memberships APIThe Memberships API from Hang — 10 operation(s) for memberships.53.3 Warwick SU Membership APIThe Warwick Students' Union publishes a Membership API for validating membership and retrieving member rost...52.6 Later Membership APIThe Membership API from Later — 7 operation(s) for membership.52.2 Cobot Membership APIRepresents a person being a member in a space. Can optionally be connected to a User.51.7 Mavrck Membership APIThe Membership API from Mavrck — 7 operation(s) for membership.51.6 MemberPress Memberships APIMemberships are the products members buy.46.4 SumUp Memberships APIEndpoints to manage user's memberships. Memberships are used to connect the user to merchant accounts and t...46.0 ADP Memberships APIList all memberships45.3 BJ's Wholesale Club Membership APIThe Membership API from BJ's Wholesale Club — 1 operation(s) for membership.45.3 University of Washington Membership APIGroup membership information44.5 Blackbird Memberships APIPer-(member, restaurant) loyalty records carrying check-in counts and tiers.43.4 DataCite membership — Fondren Library, Rice UniversityRice University is a DataCite direct member, registered 2017-11-13 as provider `rice` (symbol RICE) under F...42.7 Mode Memberships APIThe Memberships API from Mode — 2 operation(s) for memberships.42.7 ROR registration — Rice UniversityRice University's entry in the Research Organization Registry, ROR ID https://ror.org/008zs3103. It is the ...42.7 DataCite repository membership (QWBT.ULISBOA)An active DataCite repository client registered to the university's central services for minting DOIs over ...42.0 Crossref membership (7569, 16151)Two Crossref member records belong to the institution. Member 7569, "University of Ottawa Library", holds p...40.7 DataCite membership (UOTT)The University of Ottawa is a DataCite member and DOI registrant. Probed 2026-09-01: GET https://api.dataci...40.7 ROR registration (03c4mmv16)The University of Ottawa is registered in the Research Organization Registry as https://ror.org/03c4mmv16, ...40.7 OpenProject Memberships APIUsers and groups can become members of a project. Such a membership will also have one or more roles assign...40.6 Packet Host Memberships APIMembership Management (Project). Check out the product docs to learn more about [Membership](https://metal....40.5 DataCite Membership — Washington University in St. Louis LibrariesWashington University in St. Louis Libraries is a DataCite direct member, symbol WUSTL, registered 2018-08-...40.1 EZR Open PlatformThe EZR 开放平台 integration surface — 236 documented interfaces across 11 business domains (base data, member ...39.8

Thin 28 Limited public surface area

Crossref membershipGhent University is a Crossref member in its own name - member id 9286, DOI prefix 10.21825, registered in ...39.2 IDEM GARR Identity Federation membershipPolitecnico di Milano's membership of IDEM, the Italian academic identity federation run by GARR. The feder...38.5 ROR registrationThe institution's entry in the Research Organization Registry, ROR ID 01nffqt88, carrying its canonical nam...38.5 Neon One Memberships APIMembership levels and terms held by an account.37.8 Luma Memberships APIThe Memberships API from Luma — 3 operation(s) for memberships.37.5 Equinix Memberships APIMembership Management (Project). Check out the product docs to learn more about [Membership](https://metal....37.2 Fulcrum Memberships APIAccount memberships and assignments37.2 Calyptia Membership APIThe membership API from Calyptia — 2 operation(s) for membership.35.8 DataCite membership and DOI registration (member AWZY)The university is a DataCite member and DOI registrant — a fact about the institution, recorded here as a m...35.7 ROR registration (Research Organization Registry)The institution's entry in the Research Organization Registry, ROR ID https://ror.org/03a1kwz48. A registry...35.7 CVAT Memberships APIMembership of users within organizations.34.6 Fourthwall Memberships APIThe Memberships API from Fourthwall — 3 operation(s) for memberships.33.5 GakuNin academic access management federation membershipNagoya University is a participating institution in GakuNin (学術認証フェデレーション), the Japanese national academic ...33.3 Whop Memberships APIA user's access to a product; lifecycle and access management.33.2 Crossref membership — Universiti Sains MalaysiaUSM is Crossref member 8963, registering DOIs under prefixes 10.21315 (USM Press journals such as the Malay...33.1 ROR record — Universiti Sains MalaysiaUSM's Research Organization Registry identifier, https://ror.org/02rgb2k63. The identifier is the join key ...33.1 Wodify Memberships APIMembership records, templates, holds, and billing configuration.33.0 GrowthZone Memberships APIMembership types and member rosters.32.7 Patreon API v2The Patreon REST API v2 follows the JSON:API specification. It exposes campaigns, members (patrons), posts,...32.7 Crossref Memberships — Keio unitsTwo Keio units are Crossref members in their own right: member 1082, "Keio Journal of Medicine", DOI prefix...32.6 DataCite Membership — provider `keio`Keio University is a registered DataCite provider — id `keio`, symbol KEIO, memberType consortium_organizat...32.6 ROR Registration — Keio UniversityKeio University is registered in the Research Organization Registry as https://ror.org/02kn6nx58, with doma...32.6 TableCheck Memberships APIThe memberships API from TableCheck — 2 operation(s) for memberships.32.5 PayFast Subscriptions APIManage recurring billing subscription agreements31.8 Cisco Collaboration Hybrid Solutions Memberships APIThe Memberships API from Cisco Collaboration Hybrid Solutions — 2 operation(s) for memberships.30.9 Userflow REST APIThe Userflow REST API allows back-end applications to synchronize user data, track events, and manage group...30.7 Ko-fi WebhookOutbound webhook that Ko-fi HTTP POSTs to a URL you configure whenever a payment happens on your Ko-fi page...26.7 Zen Planner Memberships APIThe Memberships API from Zen Planner — 1 operation(s) for memberships.26.7

Emerging 13 Early or largely undocumented

Crossref membership (AUB)AUB is a Crossref member in its own right — member id 13566, primary name "American University of Beirut", ...25.7 Race Entry Memberships APIThe Memberships API from Race Entry — 2 operation(s) for memberships.25.3 Medrio Users and Memberships APIAdminister the account user profile and per-study memberships - read and update your user, change password,...24.8 CARSI membership (CERNET Authentication and Resource Sharing Infrastructure)Wuhan University is a registered identity provider in CARSI, China's national research-and-education identi...24.3 Crossref Membership — Servicio de Publicaciones de la UAMUAM's publications service is a Crossref member (member id 6788) and mints DOIs under prefix 10.15366, with...24.1 ROR Registration — Universidad Autónoma de MadridUAM's Research Organization Registry identifier, https://ror.org/01cby8j38, the canonical machine-readable ...24.1 Strikingly Site Management APIInternal REST API for managing Strikingly website content, sections, blog posts, store products, form submi...22.4 Crossref membershipThe University of Chile is a Crossref member, id 3330, primary name "Universidad de Chile", DOI prefix 10.5...22.1 DataCite membership and repository registrationThe University of Chile is a DataCite member, not a DataCite operator. Evidenced 2026-09-01 from the DataCi...22.1 ROR organization recordThe University of Chile's Research Organization Registry record: https://ror.org/047gc3g35, established 184...22.1 Glofox Memberships, Plans & Credits APIManage Plans (the terms, duration, and pricing of a service offering), a member's Membership against a give...21.2 Boulevard Admin API - Memberships & PackagesAccess recurring membership and prepaid package data - plan status, renewal state, and entitlements. Member...19.6 HMB APICreate and access membership information for the HMB membership.17.2

Minimal 4 Almost no public developer surface

FreshPass Delivery SubscriptionFreshPass is the Albertsons-family paid subscription that provides unlimited free grocery delivery, exclusi...9.7 E by EquinoxUltra-luxury, invitation-only tier of Equinox membership offering hyper-personalized coaching, recovery, nu...7.7 Personify MemberClicks (MC Professional) APIJSON REST API for the MemberClicks MC Professional AMS, secured with OAuth 2.0. Base URL is organization-sc...7.1 Personify Wild Apricot APIRESTful API for the Wild Apricot small-association product, secured with OAuth 2.0 against base https://api...7.1

Companies reaching this through an API (57)

These companies publish an API, specification or operation carrying “Membership” but do not classify their business under it. Listed unranked and kept out of the count above, because one tagged operation is not a statement about what a company does.

Acme Markets ADP AfterShip Amazon Clean Rooms Amazon Web Services American University of Beirut Automattic Autonomous University of Madrid Bonitasoft Boulevard Calyptia Cisco Collaboration Hybrid Solutions Close Cloudflare Commerce Layer Confluence CVAT Eclipse Foundation Equinix Fintecture Fulcrum Ghent University Griffin GrowthZone Guardian Life Hint Health Keio University Later Luma Mapp Marketing Cloud Mavrck Medrio Mode Nagoya University NationBuilder Neon One OpenProject Packet Host PayFast PixieBrix Politecnico di Milano Race Entry Rice University SumUp TableCheck Universiti Sains Malaysia University of Chile University of Lisbon University of Ottawa University of Tübingen

Show all 57 companies ↓

University of Warwick University of Washington Userflow Washington University in St. Louis Webex Wodify Wuhan University

Score breakdown

Frequency

65.3

log-scaled weighted occurrences

Breadth

2.4

spread across providers

Quality lift

27.1

mean composite of providers using it

Cohesion

0.0

strength of nearest seed neighbor

Where this tag comes from

Provider tag91

Api tag85

Openapi tag39

Openapi op tag180

Cohort brief

Auto-generated

The 89 providers in the APIs.io catalog tagged Membership, scored on the Kin Score. Every figure below is computed from the catalog — nothing here is written.

Providers

of 91 in the catalog

Mean Kin Score

22.4

-0.5 vs catalog 22.9

Mean Agent Readiness

-0.9 vs catalog 11.9

Spread

0–78

median 15.8 · σ 16.2

How the 89 split by band

Exemplar 2Strong 1Developing 12Thin 16Emerging 36Minimal 22

Facet averages, against the whole catalog

Facet	This cohort	Catalog	Difference	Scored
Access Clarity	32.8	26.5	+6.3	89
Discoverability	58.4	58.1	+0.3	89
Operational Transparency	12.3	13.7	-1.4	89
Contract Governance	4.7	6.3	-1.6	89
Contract Quality	15.8	17.6	-1.8	89
Developer Ergonomics	19.3	23.2	-3.9	89

A facet is averaged over the members that carry it, not over the whole cohort — the “Scored” column is that count. Averaging an absent facet as zero would score our own coverage gaps as the providers’ posture.

What this cohort publishes

Artifact	This cohort	Catalog	Difference
MCP server (any)	12%	14%	-2
MCP server (first-party)	10%	12%	-2
Agent Skills	0%	0%	0
OAuth scopes	15%	11%	+4
Security	100%	98%	+2
Arazzo workflows	0%	2%	-2
Governance rules	10%	14%	-4

mcp_pct counts any mcp/ artifact including ones API Evangelist derived from the provider OpenAPI; mcp_first_party_pct counts only servers the provider publishes. Prefer the latter.

Top by Kin Score

1 Ghost 78
2 Antavo 66.9
3 Kartra 58.6
4 ServiceTitan 53.6
5 Hang 53.3
6 SendOwl 53.2
7 Cobot 51.7
8 Teachable 49.7
9 MemberPress 46.4
10 Unlock Protocol 45.9

Work with this as data

Every tag here is available over the APIs.io API and to AI agents over MCP.

MCP server

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https://apis.io/mcp

Tools for tags

7 MCP tools reach this

find_tagsBrowse and filter every tag in the catalog.
get_cohortThis tag as a scored cohort — every provider carrying it, with scores.
cohort_statsPRO — the distribution across this tag: mean, median, band split, adoption rates.
cohort_rankingsPRO — the leaderboard, on composite AND agent-readiness axes.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This tag

curl "https://apis.io/api/v1/tags/membership"

All tags

curl "https://apis.io/api/v1/tags?limit=25"

As a scored cohort

curl "https://apis.io/api/v1/cohorts/tag/membership"

The distribution (Pro)

curl "https://apis.io/api/v1/cohorts/tag/membership/stats" \
  -H "X-API-Key: $APIS_IO_KEY"

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Membership

Providers using this tag (91)

APIs with this tag (86)