niche · -0.7 capabilitymarket resourceschemadomain

Protocol

Score 18.8 / 100 24 providers +55 via APIs 69 APIs Search apis.io →
Business capabilities this tag reaches
Agent Infrastructure & Agentic Commerce 2
Variants seen in the corpus: ProtocolsProtocol

Providers using this tag (24)

Ranked by API Evangelist rating — Exemplar and Strong are expanded by default.

Strong 1 Solid coverage with minor gaps
wayza-comCompanyArtificial IntelligenceIntegration1 API55.4
Developing 3 Usable, with meaningful gaps to close
iLangCompanyArtificial IntelligenceOpen Source1 API44.2CflowAutomationBusiness Process AutomationIntegrationNo-Code1 API47.1Swift NavigationCompanyGNSSPrecise PositioningLocation4 APIs43.8
Thin 3 Limited public surface area
Capability Host ProtocolArtificial IntelligenceGovernanceCapabilities1 API31.8Here Not There LabsCompanyMessagingDecentralizedWeb31 API31.8IsometricCarbon RemovalCarbon RegistryClimateClimate Tech3 APIs31.2
Emerging 12 Early or largely undocumented
TapestryCompanySocialSolana2 APIs25.5TariCompanyBlockchainCryptocurrency1 API23.6KOA LabsAgentsMCPA2AAgent Discovery2 APIs23.5FarcasterFarcasterSocialDecentralized1 API23.3OT FabricCompanyIndustrial IoTOperational TechnologyOpen Source2 APIs18.8MQTTMQTTMessagingPublish SubscribeIoT2 APIs15.4AaveDeFiLendingBorrowingLiquidity8 APIs14.9PartyDAOCompanyWeb3BlockchainEthereum11.7Cap'n ProtoBinary FormatCapability-Based SecurityCode GenerationIPC5 APIs11.6Internet Engineering Task ForceInternetRFCStandards6 APIs25.4NerosCompanyDefenseDronesUnmanned Systems1 API20.3InferaCompanyLaboratory AutomationBiotechnologyLife Sciences15.9
Minimal 5 Almost no public developer surface
Internet Assigned Numbers AuthorityDomainsDNSIP AddressingMedia Types3 APIs10.3BitcoinCompanyCryptocurrencyBlockchainBitcoin9.9Agent ManifestRegistryValidationOpen Source1 API9.6Huangting ProtocolLifeformOSTaoismArtificial IntelligenceOpen Source5.1PlanetaryCompanySocialSocial MediaDecentralized5.1

APIs with this tag (69)

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 3 Complete, well-documented, and agent-ready
Delx Protocol APIThe protocol API from Delx — 5 operation(s) for protocol.75.7LDAP Protocol InterfaceLightweight Directory Access Protocol interface for querying and modifying Active Directory.71.3Match It Up Protocol APIThe Protocol API from Match It Up — 3 operation(s) for protocol.69.4
Strong 7 Solid coverage with minor gaps
Cisco Umbrella Protocols APIThe Protocols API from Cisco Umbrella — 2 operation(s) for protocols.63.6Atomadic Tech Protocol APIProtocol discovery endpoints: MCP and A2A agent card62.0Vaultfire Protocol Protocol APIProtocol-wide stats and contracts59.0AxioRank Protocols APIThe Protocols API from AxioRank — 1 operation(s) for protocols.58.8Vorn Protocol APIThe Protocol API from Vorn — 2 operation(s) for protocol.57.3XGuard Protocols APIThe Protocols API from XGuard — 1 operation(s) for protocols.55.1Leia Protocol APIThe Protocol API from Leia — 1 operation(s) for protocol.54.7
Developing 14 Usable, with meaningful gaps to close
SSSNACK Protocols APIThe Protocols API from SSSNACK — 2 operation(s) for protocols.54.1Cambio Healthcare Systems Protocol APIThe Protocol API from Cambio Healthcare Systems — 2 operation(s) for protocol.51.4AiFinPay Protocol APIprotocol router — see backend/routes/protocol.js51.3philidor-io Protocols APIThe Protocols API from philidor-io — 2 operation(s) for protocols.50.9Dyno Protocols APIThe protocols API from Dyno — 7 operation(s) for protocols.49.3sqlguard-io Protocol APIThe protocol API from sqlguard-io — 1 operation(s) for protocol.48.2Delta Lake Storage FrameworkThe Delta Lake storage framework defines the on-disk transaction log and protocol that adds ACID transactio...47.3Cenevo Protocols APIThe Protocols API from Cenevo — 2 operation(s) for protocols.45.6Golioth PouchNon-IP device-to-cloud transport protocol from Golioth, with a companion Bluetooth gateway reference implem...44.6Interhyp Protocol APIaccess to submission protocol43.8Swift Binary Protocol (SBP)The native binary protocol for Swift Navigation devices — Piksi and Duro GNSS receivers and the Starling po...43.8Signal Protocol SpecificationsThe Signal Protocol Specifications define the core cryptographic protocols that underpin Signal's end-to-en...43.2Fluentd Forward ProtocolThe Fluentd Forward Protocol is a binary protocol used to transport event streams between Fluentd nodes and...39.6TetraScience Protocols APIThe Protocols API from TetraScience — 11 operation(s) for protocols.39.4
Thin 27 Limited public surface area
BotFriendly Protocols APIThe Protocols API from BotFriendly — 1 operation(s) for protocols.38.3Collaborative Drug Discovery Protocols APIProtocols and their readout data38.0DeBank Protocol APIGet protocol info37.9Materials Zone Protocols APIProtocols are used to group parameters in tables.37.1Orca Protocol APIOrca protocol information endpoints37.0AcuiQ Protocols APIThe Protocols API from AcuiQ — 1 operation(s) for protocols.35.3Euler Finance Protocol APIProtocol-wide summary endpoints and aggregate metrics. In v3, these endpoints are explicitly summary-orient...35.2Apache Thrift Server APIThe Thrift Server API provides server implementations for hosting Thrift services including TSimpleServer (...32.8Physical Capability Cloud Protocol APIThe Protocol API from Physical Capability Cloud — 5 operation(s) for protocol.32.8Physical Capability Cloud Protocols APIThe Protocols API from Physical Capability Cloud — 7 operation(s) for protocols.32.8Superform Protocol APIThe Protocol API from Superform — 3 operation(s) for protocol.32.2Towns ProtocolTowns Protocol is an open, decentralized messaging protocol built on Base. Builders integrate via first-par...31.8LiteLLM MCP APIProvides /mcp endpoints for Model Context Protocol (MCP) integration, enabling LLMs to interact with extern...31.7Ricoh USA Protocol APICore OSC protocol endpoints31.6Opentrons Python Protocol APIThe Opentrons Python Protocol API is an open-source Python framework for writing automated biology lab prot...31.5Origin Protocol APIThe protocol API from Origin Protocol — 8 operation(s) for protocol.31.3AMQPAdvanced Message Queuing Protocol. AMQP 1.0 is both an OASIS standard and an International Standard (ISO/IE...29.3MQTTOASIS standard messaging protocol for the Internet of Things. Lightweight publish/subscribe transport for r...29.3STOMPSimple (or Streaming) Text Oriented Messaging Protocol. Lightweight, text-based wire protocol for message-o...29.3Monad Machine Payments ProtocolProtocol specification for programmable machine-to-machine payments on Monad, including account, channel, a...29.2Labguru Protocols APIThe Protocols API from Labguru — 2 operation(s) for protocols.29.0Sommelier Protocol APIProtocol-wide metrics such as total value locked.28.7Tezos Protocols APIThe Protocols API from Tezos — 6 operation(s) for protocols.28.4TzKT Governance APIThe Governance API exposes Tezos on-chain governance data including voting periods, proposals, ballots, and...28.4TzKT Protocols APIThe Protocols API returns metadata for each Tezos protocol version including hash, first and last cycle, co...28.4docomo Mail IMAP InterfaceThe docomo Mail IMAP interface is the one machine-interface specification NTT DOCOMO publishes openly, with...27.9MCP SpecificationThe authoritative protocol definition for the Model Context Protocol, maintained at modelcontextprotocol.io...26.7
Emerging 15 Early or largely undocumented
Messari Protocols APIThe Protocols API from Messari — 5 operation(s) for protocols.25.8Cucumber MessagesProtocol-buffer / JSON Schema specification of the messages exchanged between Cucumber components (parsers,...25.7Yarn ProtocolsYarn supports a rich set of dependency protocols beyond `npm:` semver — `git:`, `github:`, `file:`, `link:`...25.3Filecoin Protocol Actor APIBuilt-in actor method interface exposed through Filecoin Virtual Machine (FVM). Covers Account, Datacap, Mi...24.6Bloomberg Open API (BLPAPI)Bloomberg's proprietary socket-based API protocol for accessing Bloomberg data, providing a high-performanc...24.3Eclipse RDF4J Protocol APIProtocol version of the server.24.3APEX — Adaptive Payload EXchangeAPEX is Neros Technologies' open, MIT-licensed plug-and-play protocol for connecting drone platforms (hosts...20.3Dorsal APIDorsal API as documented publicly: 7 operations. Contract generated from the documentation by API Evangelis...20.3Helium Protobuf DefinitionsCanonical protocol buffer definitions for Helium message formats used across packet routing, oracles, and r...19.6OT Fabric Protocol Libraries and CLIsOpen-source, MIT-licensed pure-Go protocol libraries (Modbus, OPC UA, BACnet/IP, IEC 60870-5-104, IEC 61850...18.8Agent Traffic Lab Protocol APIThe Protocol API from Agent Traffic Lab — 1 operation(s) for protocol.17.0MQTT Version 3.1.1 ProtocolPrevious OASIS Standard version of MQTT, still widely deployed across IoT brokers, devices, and cloud platf...15.4MQTT Version 5.0 ProtocolOASIS Standard publish/subscribe messaging protocol for IoT and M2M communication. MQTT v5.0 defines the wi...15.4Aave V4 Protocol (Smart Contracts)Next-generation Aave V4 protocol implementation with unified liquidity layer, hub-and-spoke architecture, a...14.9Cap'n Proto RPC ProtocolCap'n Proto's RPC protocol is a capability-based RPC layer that supports promise pipelining, object referen...11.6
Minimal 3 Almost no public developer surface
IANA Protocol RegistriesThe IANA Protocol Registries publish the authoritative assignments for Internet protocol parameters. Bulk r...10.3Postfix SMTPPostfix implements SMTP (RFC 5321) for sending and receiving electronic mail, with submission (port 587), S...9.0OpenLDAP Directory ServiceLDAP v3 protocol interface provided by the slapd directory server for reading, writing, and managing hierar...6.0

Companies reaching this through an API (55)

These companies publish an API, specification or operation carrying “Protocol” 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.

AcuiQ Agent Traffic Lab AiFinPay Apache Thrift Atomadic Tech AxioRank Bloomberg Proprietary Technologies BotFriendly Cambio Healthcare Systems Cenevo Cisco Umbrella Collaborative Drug Discovery Cucumber DeBank Delta Lake Delx Dorsal Dyno Eclipse RDF4J Euler Finance Events Filecoin Fluentd Golioth Helium Network Interhyp Labguru Leia LiteLLM Match It Up Materials Zone Messari Microsoft Active Directory Model Context Protocol (MCP) Monad NTT Docomo OpenLDAP Opentrons Orca Origin Protocol philidor-io Physical Capability Cloud Postfix Ricoh USA Signal Sommelier sqlguard-io SSSNACK Superform TetraScience
Show all 55 companies ↓
Tezos Vaultfire Protocol Vorn XGuard Yarn

Score breakdown

Frequency
54.4
log-scaled weighted occurrences
Breadth
0.3
spread across providers
Quality lift
23.1
mean composite of providers using it
Cohesion
3.3
strength of nearest seed neighbor

Related tags

Vault 5 co-occurrences Reference 5 co-occurrences Schema 6 co-occurrences TypeScript 5 co-occurrences DeFi 9 co-occurrences x402 6 co-occurrences

Where this tag comes from

Provider tag24
Api tag68
Openapi tag34
Openapi op tag120

Work with this as data

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

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

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/protocol"
All tags 
curl "https://apis.io/api/v1/tags?limit=25"
As a scored cohort (paid plan)
The distribution (Pro)

Calls without X-API-Key need no key. Calls with it need a paid plan — get a key.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.