Protocol
Variants seen in the corpus:
Protocolprotocol
Providers using this tag (48)
Ranked by API Evangelist rating — Exemplar and Strong are expanded by default.
Developing 6 Usable, with meaningful gaps to close
Thin 16 Limited public surface area
Emerging 17 Early or largely undocumented
APIs with this tag (47)
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 →
Developing 6 Usable, with meaningful gaps to close
Interhyp protocol APIaccess to submission protocolRicoh USA Protocol APICore OSC protocol endpointsPocket Network Shannon Chain APICosmos SDK-based REST and gRPC API for interacting with the Pocket Network Shannon protocol chain. Provides...Golioth PouchNon-IP device-to-cloud transport protocol from Golioth, with a companion Bluetooth gateway reference implem...Orca protocol APIOrca protocol information endpointsEuler Finance Protocol APIProtocol-wide summary endpoints and aggregate metrics. In v3, these endpoints are explicitly summary-orient...
Thin 15 Limited public surface area
TzKT Governance APIThe Governance API exposes Tezos on-chain governance data including voting periods, proposals, ballots, and...Monad Machine Payments ProtocolProtocol specification for programmable machine-to-machine payments on Monad, including account, channel, a...Superform Protocol APIThe Protocol API from Superform — 3 operation(s) for protocol.Fluentd Forward ProtocolThe Fluentd Forward Protocol is a binary protocol used to transport event streams between Fluentd nodes and...Filecoin Protocol Actor APIBuilt-in actor method interface exposed through Filecoin Virtual Machine (FVM). Covers Account, Datacap, Mi...LDAP Protocol InterfaceLightweight Directory Access Protocol interface for querying and modifying Active Directory.Towns ProtocolTowns Protocol is an open, decentralized messaging protocol built on Base. Builders integrate via first-par...Opentrons Python Protocol APIThe Opentrons Python Protocol API is an open-source Python framework for writing automated biology lab prot...Origin Protocol protocol APIThe protocol API from Origin Protocol — 8 operation(s) for protocol.Eclipse RDF4J Protocol APIProtocol version of the server.docomo Mail IMAP InterfaceThe docomo Mail IMAP interface is the one machine-interface specification NTT DOCOMO publishes openly, with...Snapchain HTTP APIThe read/write REST interface a Snapchain node serves on port 3381 under the /v1 path. Read endpoints (cast...Apache Thrift Server APIThe Thrift Server API provides server implementations for hosting Thrift services including TSimpleServer (...Sommelier Protocol APIProtocol-wide metrics such as total value locked.Bloomberg Open API (BLPAPI)Bloomberg's proprietary socket-based API protocol for accessing Bloomberg data, providing a high-performanc...
Emerging 24 Early or largely undocumented
Cucumber MessagesProtocol-buffer / JSON Schema specification of the messages exchanged between Cucumber components (parsers,...Restate Service ProtocolThe Restate Service Protocol is the wire protocol Restate Server uses to communicate with handler endpoints...Aave V4 Protocol (Smart Contracts)Next-generation Aave V4 protocol implementation with unified liquidity layer, hub-and-spoke architecture, a...MCP SpecificationThe authoritative protocol definition for the Model Context Protocol, maintained at modelcontextprotocol.io...Helium Protobuf DefinitionsCanonical protocol buffer definitions for Helium message formats used across packet routing, oracles, and r...APEX — Adaptive Payload EXchangeAPEX is Neros Technologies' open, MIT-licensed plug-and-play protocol for connecting drone platforms (hosts...MQTT Version 3.1.1 ProtocolPrevious OASIS Standard version of MQTT, still widely deployed across IoT brokers, devices, and cloud platf...MQTT Version 5.0 ProtocolOASIS Standard publish/subscribe messaging protocol for IoT and M2M communication. MQTT v5.0 defines the wi...CoAPThe Constrained Application Protocol, defined in IETF RFC 7252, is a RESTful protocol for constrained devic...gRPC StreaminggRPC supports four call patterns — unary, server streaming, client streaming, and bidirectional streaming —...MQTTA lightweight publish/subscribe protocol standardized by OASIS, designed for constrained devices and low-ba...Server-Sent Events (SSE)A unidirectional server-to-client streaming protocol over HTTP, defined by the WHATWG HTML Living Standard....WebRTCA peer-to-peer realtime communication framework for audio, video, and arbitrary data channels, standardized...WebSocketA full-duplex communication protocol over a single TCP connection, standardized by the IETF as RFC 6455 and...Delta Lake Storage FrameworkThe Delta Lake storage framework defines the on-disk transaction log and protocol that adds ACID transactio...Cap'n Proto RPC ProtocolCap'n Proto's RPC protocol is a capability-based RPC layer that supports promise pipelining, object referen...AMQPAdvanced Message Queuing Protocol. AMQP 1.0 is both an OASIS standard and an International Standard (ISO/IE...MQTTOASIS standard messaging protocol for the Internet of Things. Lightweight publish/subscribe transport for r...STOMPSimple (or Streaming) Text Oriented Messaging Protocol. Lightweight, text-based wire protocol for message-o...gRPC StreaminggRPC defines four RPC styles, three of which are streaming: server streaming, client streaming, and bidirec...Server-Sent Events (SSE)One-directional HTTP-based streaming from server to client using the `text/event-stream` media type. Define...WebSocketFull-duplex, bidirectional streaming protocol over a single TCP connection, upgraded from HTTP. RFC 6455. F...RTSP ProtocolThe Real-Time Streaming Protocol (RTSP) is a stateful protocol defined in RFC 2326 (1.0) and RFC 7826 (2.0)...LDAPLightweight Directory Access Protocol for accessing and maintaining distributed directory information servi...
Minimal 2 Almost no public developer surface
Score breakdown
Frequency
50.7
log-scaled weighted occurrences
Breadth
1.3
spread across providers
Quality lift
28.4
mean composite of providers using it
Cohesion
3.0
strength of nearest seed neighbor
Related tags
IETF 6 co-occurrences
RPC 5 co-occurrences
gRPC 5 co-occurrences
Ethereum 5 co-occurrences
Blockchain 14 co-occurrences
DeFi 6 co-occurrences
Open-Source 17 co-occurrences
SDK 10 co-occurrences
Where this tag comes from
Provider tag18
Api tag47
Openapi tag8
Openapi op tag22
Cohort brief
Auto-generatedThe 48 providers in the APIs.io catalog tagged Protocol, scored on the Kin Score. Every figure below is computed from the catalog — nothing here is written.
Providers
48
all scored
Mean Kin Score
23.8
+3.1 vs catalog 20.7
Mean Agent Readiness
10.6
+0.9 vs catalog 9.7
Spread
4.1–46.3
median 24.7 · σ 11.8
How the 48 split by band
Exemplar 0Strong 0Developing 6Thin 16Emerging 17Minimal 9
Facet averages, against the whole catalog
| Facet | This cohort | Catalog | Difference | Scored |
|---|---|---|---|---|
| Contract Quality | 24.9 | 17.5 | +7.4 | 48 |
| Discoverability | 66.7 | 60.4 | +6.3 | 48 |
| Developer Ergonomics | 23.1 | 17.9 | +5.2 | 48 |
| Operational Transparency | 16.2 | 11.3 | +4.9 | 48 |
| Contract Governance | 8.2 | 6.4 | +1.8 | 48 |
| Access Clarity | 17 | 22.3 | -5.3 | 48 |
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) | 13% | 16% | -3 |
| MCP server (first-party) | 2% | 7% | -5 |
| Agent Skills | 0% | 0% | 0 |
| OAuth scopes | 2% | 9% | -7 |
| Security | 96% | 88% | +8 |
| Arazzo workflows | 2% | 2% | 0 |
| Governance rules | 31% | 13% | +18 |
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 Interhyp 46.3
- 2 Ricoh USA 44.5
- 3 Pocket Network 43.1
- 4 Golioth 42.9
- 5 Orca 40.5
- 6 Euler Finance 40.1
- 7 Tezos 39.1
- 8 Monad 39
- 9 Superform 35.3
- 10 Fluentd 35
Top by Agent Readiness
- 1 Interhyp 32.9
- 2 Orca 31.7
- 3 Euler Finance 30.6
- 4 Microsoft Active Directory 24.8
- 5 Fluentd 23.4
- 6 Opentrons 23
- 7 Monad 22.3
- 8 Sommelier 21.9
- 9 Here Not There Labs 20.7
- 10 Superform 20.7
All 48 members of this roster resolve to a scored provider in
the catalog.Generated from the catalog build of
25 August 2026, across 26891
providers, using the same computation served by the
APIs.io cohort API. Briefs are published for rosters of
5 or more scored providers; below that a distribution is not meaningful.
Work with this as data
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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.
Call it yourself
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As a scored cohort
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The distribution (Pro)
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-H "X-API-Key: $APIS_IO_KEY"Discovery needs no key. Ratings and market analysis are Pro.