Specifications & Contracts
The machine-readable contracts APIs are defined, validated and governed with. 131 in the catalog.
| Standard | What it is |
|---|---|
| 3-D Secure | 3-D Secure is an EMVCo messaging protocol that adds cardholder authentication to card-not-present payments, sharing risk data between the merchant,... |
| ABNF | RFC 5234 defines Augmented Backus-Naur Form, the notation the IETF uses to specify the exact syntax of a protocol element. It is the shared grammar... |
| AEP | AEP is an open API design specification for resource-oriented REST and gRPC APIs — a numbered set of design guidelines (resources, standard methods... |
| AI Catalog | The AI Catalog Standard is the data model underneath Agentic Resource Discovery — a JSON manifest a publisher hosts at `/.well-known/ai-catalog.jso... |
| AI Preferences (aipref) | The IETF aipref working group is defining a vocabulary for expressing preferences about how content may be used by AI systems, and how to attach th... |
| API Blueprint | API Blueprint is a Markdown-based specification language for designing and documenting web APIs. It uses a human-readable syntax to describe resour... |
| API Catalog | RFC 9727 is the Standards Track specification that defines the `/.well-known/api-catalog` URI and the `api-catalog` link relation. A request to tha... |
| API Commons | API Commons is a collection of open-source building blocks for API operations. It began as a machine-readable way to define the parts of an API, an... |
| APIs.json | APIs.json is a machine-readable metadata format used to describe APIs (Application Programming Interfaces) and their associated resources. It acts ... |
| Accord Project | Accord Project is an open-source stack for smart legal contracts. Its Concerto modeling language and contract templates now position it as the agre... |
| AdES | The AdES family — PAdES for PDF, XAdES for XML, CAdES for CMS-wrapped data — are the ETSI standards defining how an advanced or qualified electroni... |
| Agent2Agent | The Agent2Agent (A2A) Protocol is an open standard for communication and interoperability among independent—often opaque—AI agent systems. Because ... |
| Agentic Resource Discovery | Agentic Resource Discovery (ARD) is a proposed open standard for the discovery layer the agentic web is missing — the step that happens *before* in... |
| Amazon S3 API | The HTTP API of Amazon Simple Storage Service, launched in March 2006 and since cloned by MinIO, Ceph, Cloudflare R2, Backblaze B2, Google Cloud St... |
| Arazzo | The Arazzo Specification is a community-driven, open standard within the OpenAPI Initiative (a Linux Foundation Collaborative Project). It defines ... |
| Asset Administration Shell | The Asset Administration Shell is the Industrie 4.0 standard for an industrial digital twin, maintained by the Industrial Digital Twin Association.... |
| AsyncAPI | AsyncAPI is an open specification for defining and documenting event-driven and asynchronous APIs in a machine-readable format. It describes messag... |
| Backstage Software Catalog Format | Backstage’s Software Catalog format is a structured, YAML-based specification that describes software components, services, APIs, resources, and th... |
| Bean Validation | Bean Validation is a Java/Jakarta EE specification (JSR 303, JSR 349, and JSR 380) that defines a declarative, annotation-based model for validatin... |
| Bruno Collection | Bruno collections are organized sets of API requests and environments within the Bruno API client, allowing developers to structure, test, and shar... |
| Bruno Environment | A Bruno environment is a set of key–value variables that let you switch configurations—such as URLs, tokens, or credentials—so you can run the same... |
| CAIP | The Chain Agnostic Improvement Proposals define identifiers and conventions that work across blockchains rather than within one — a chain ID format... |
| CALM | CALM (Common Architecture Language Model) is a machine-readable specification for describing software architecture as versioned code. It defines a ... |
| CDMI | SNIA's RESTful HTTP interface for cloud storage, standardized as ISO/IEC 17826 — data objects, container objects and queue objects, with metadata-d... |
| CKAN Action API | CKAN is the open-source data portal software behind a large share of the world's government open-data sites, and its Action API is the uniform JSON... |
| CLI Agent Spec | CLI Agent Spec is a behavioral contract for command-line tools invoked by AI agents rather than humans. It documents 74 failure modes an agent hits... |
| CMIS | OASIS's standard interface to enterprise content repositories — folders, documents, versioning, ACLs, a SQL-like query language and a change log — ... |
| CSIO | CSIO is Canada's insurance data standards body, and the operator of what appears to be the only public, tiered API certification programme in insur... |
| CWL | The Common Workflow Language is a vendor-neutral standard for describing analysis workflows and command-line tools so that they run identically acr... |
| Certificate Transparency | RFC 6962 and its v2 successor RFC 9162 define append-only, publicly auditable Merkle-tree logs of issued TLS certificates. The mechanism matters we... |
| Chantico | Chantico is a Kubernetes operator that brings energy intelligence to cloud-native data centers, monitoring the power usage of devices such as PDUs ... |
| CloudEvents | CloudEvents is a CNCF specification for describing event data in a common, vendor-neutral format. It defines required and optional context attribut... |
| CobaltCore | CobaltCore is an opinionated OpenStack distribution built on IronCore's foundation to run non-cloud-native workloads, with KVM hypervisor operators... |
| Collection+JSON | Collection+JSON is a JSON-based hypermedia media type for managing and querying collections of resources. It defines a standard document structure ... |
| DOI | A DOI is a persistent identifier for a document or dataset, standardised as ISO 26324 and operated through registration agencies — Crossref for sch... |
| EIP-1559 | EIP-1559 replaced Ethereum's first-price fee auction with a protocol-set base fee that adjusts with demand and is burned, plus an optional priority... |
| EMV Agentic Payments Framework | EMV Agentic Payments – Framework for Specifications is EMVCo's draft foundation for card-based payments made by AI agents on a consumer's behalf. I... |
| EMV Digital Payment Credential | The EMV Digital Payment Credential (DPC) is EMVCo's work to define a verifiable digital credential for card payments — a common, interoperable way ... |
| EMV Payment Tokenisation | EMV Payment Tokenisation replaces a card's primary account number (PAN) with a payment token that is constrained in how it can be used — to a speci... |
| EMV Secure Remote Commerce | EMV Secure Remote Commerce (SRC) is the EMVCo specification framework for a consistent, secure online card checkout, and the baseline behind the ne... |
| ERC-20 | ERC-20 is the Ethereum token standard: a small interface of six functions and two events that any fungible token contract implements. Because every... |
| ERC-721 | ERC-721 is the Ethereum standard for non-fungible tokens — assets that are individually distinguishable rather than interchangeable. It defines own... |
| FDC3 | FDC3 (Financial Desktop Connectivity and Collaboration Consortium) is an open standard for interoperability between financial desktop applications.... |
| FIXM | FIXM is the standard data model for exchanging flight information between air traffic management systems, developed jointly by the FAA, EUROCONTROL... |
| GBFS | GBFS is the open data standard for shared mobility — bikes, scooters, mopeds and car share — describing system information, station status and free... |
| Gardener | Gardener is an open source system that delivers Kubernetes clusters as a service across infrastructures: an extension API server and controllers th... |
| GraphQL | A query language for APIs and a runtime for executing those queries with existing data, providing a complete and understandable description of the ... |
| Greenhouse | Greenhouse is a cloud operations platform for day-two management of large, distributed Kubernetes infrastructure: team-based access control across ... |
| HAL | HAL (Hypertext Application Language) is a media-type specification for representing resources and their links in JSON or XML. It provides a simple,... |
| HTTP QUERY Method | RFC 10008 defines QUERY, an HTTP method that is safe and idempotent like GET but carries a request body like POST. It exists for the operation ever... |
| I/O Docs | I/O Docs was an early machine-readable API description format and interactive documentation framework, released as open source by Mashery in 2011. ... |
| IAB Tech Lab AAMP and OpenProposal | AAMP is IAB Tech Lab's umbrella for agentic advertising. Its 3.0 release adds OpenProposal, a draft format for sellers to describe advertising prod... |
| IronCore | IronCore is an open source system for managing compute, storage and networking workloads across providers, exposing a declarative infrastructure-as... |
| JAX-WS | JAX-WS (Java API for XML Web Services), now Jakarta XML Web Services, is the Java specification for building and consuming SOAP-based web services ... |
| JPA | JPA (Java Persistence API), now standardized as Jakarta Persistence, is the Java specification for object-relational mapping that lets applications... |
| JSF | JSF (JavaServer Faces), now standardized as Jakarta Faces, is a Java specification for building component-based, server-side user interfaces for we... |
| JSON Pointer | RFC 6901 defines a string syntax for identifying one specific value inside a JSON document — a slash-delimited path like /components/schemas/Produc... |
| JSON Schema | JSON Schema enables the confident and reliable use of the JSON data format, bringing consistency, validity, and interoperability to enterprise oper... |
| JSON-LD | JSON-LD (JavaScript Object Notation for Linking Data) is a W3C standard for expressing linked data in JSON. It adds lightweight semantics to ordina... |
| JSON:API | JSON:API is a specification for building APIs in JSON that standardizes how clients fetch and modify resources, including pagination, filtering, sp... |
| JSR-303 | JSR-303 (Bean Validation) is the Java specification that defines a metadata model and API for declaring and enforcing validation constraints on Jav... |
| Jakarta EE | Jakarta EE is the open-source, vendor-neutral set of specifications for building enterprise Java applications, stewarded by the Eclipse Foundation ... |
| Java EE | Java EE (Java Platform, Enterprise Edition), formerly J2EE, is Oracle's set of specifications for building large-scale, multi-tier enterprise Java ... |
| MCP Registry | The MCP Registry gives MCP clients a list of MCP servers, and server.json is the standardized file that describes an MCP server for registry publis... |
| MCP Server Cards | An MCP Server Card is a static metadata document that describes a remote MCP server well enough for a client to discover and connect to it. Domain-... |
| MDS | MDS is the data standard cities use to regulate shared micromobility, developed by the Los Angeles Department of Transportation and now governed by... |
| Machine Payments Protocol (MPP) | The Machine Payments Protocol (MPP) is an open specification that finally gives HTTP's long-reserved `402 Payment Required` status code a defined s... |
| Mastercard Agent Pay | Mastercard Agent Pay is Mastercard's program for agent-initiated payments. Its acceptance framework registers and verifies agents before they trans... |
| Microcks Examples | APIExamples is Microcks' own specification format for defining reusable request/response examples that drive Microcks mocks and contract tests, ind... |
| Model Context Protocol (MCP) | MCP (Model Context Protocol) is an open protocol that standardizes how applications provide context to large language models (LLMs). It offers a co... |
| NAICS | NAICS is the North American Industry Classification System — the six-digit code set that the United States, Canada and Mexico use to say what a bus... |
| Nextflow | Nextflow is a workflow language and runtime for data-driven computational pipelines, created in 2013 at the Centre for Genomic Regulation and now d... |
| OAuth 2.0 Protected Resource Metadata | RFC 9728 is the Standards Track specification that lets an API describe how it is protected, in a JSON document served at `/.well-known/oauth-prote... |
| OCI | OCI (Open Container Initiative) is an open governance project under the Linux Foundation that defines vendor-neutral specifications for container i... |
| OCI Distribution Specification | The OCI Distribution Specification defines the HTTP API a container registry exposes for pushing, pulling and discovering artifacts, including the ... |
| OCI Image Specification | The OCI Image Specification defines the container image format — the manifest, the image configuration, the filesystem layers and the descriptors t... |
| OCI Runtime Specification | The OCI Runtime Specification defines the configuration, execution environment and lifecycle of a container — what a runtime is handed and what ope... |
| ODRL (Open Digital Rights Language) | ODRL is a W3C language for expressing permissions, prohibitions and obligations over content and services. A draft charter for a W3C Digital Policy... |
| OData | OData (Open Data Protocol) is an OASIS and ISO/IEC-approved standard for building and consuming RESTful APIs, defining consistent conventions for q... |
| OMOP CDM | The Observational Medical Outcomes Partnership Common Data Model is a standardized relational schema and vocabulary for observational health data, ... |
| Open Agentic Schema Framework | The Open Agentic Schema Framework (OASF) is a standardized schema system for defining and managing AI agent capabilities, interactions and metadata... |
| Open Collections | A modern, developer-first specification pioneered by Bruno for defining and sharing API collections. Designed for simplicity and collaboration. |
| Open Component Model | The Open Component Model (OCM) is an open standard for describing software bills of delivery (SBoD) — a technology-agnostic, machine-readable forma... |
| Open Graph Protocol | The Open Graph Protocol is a set of metadata tags that let any web page describe itself as a rich object — title, type, image, description, canonic... |
| Open Resource Discovery | Open Resource Discovery (ORD) is a protocol that lets applications and services self-describe their exposed resources and capabilities — APIs, even... |
| OpenAPI | OpenAPI (formerly known as Swagger) is a specification for building, documenting, and consuming RESTful APIs. It defines a standard, language-agnos... |
| OpenAPI Overlays | The Overlay Specification is an auxiliary standard that complements the OpenAPI Specification. An OpenAPI description defines API operations, data ... |
| OpenCLI Specification | OpenCLI Specification is a YAML/JSON document format for describing a command-line interface the way OpenAPI describes an HTTP API — a versioned `o... |
| OpenControlPlane | OpenControlPlane (openMCP) delivers extensible Infrastructure- and Configuration-as-Data capabilities as a service: managed Kubernetes control plan... |
| OpenPredicate (formerly JSON Query Language) | JSON Query Language is a JSON-encoded, SQL-flavoured predicate language for the request body of search operations, described entirely by a single J... |
| OpenRTB | OpenRTB is the IAB Tech Lab specification for real-time bidding — the message format and protocol by which an ad exchange asks demand-side platform... |
| OpenTelemetry GenAI Semantic Conventions | The OpenTelemetry GenAI Semantic Conventions define spans, metrics and events for generative AI — LLM client inference, agents, tool execution, emb... |
| OpenTelemetry Semantic Conventions | The OpenTelemetry Semantic Conventions define a common set of attribute names and meanings for telemetry, so traces, metrics, logs and events from ... |
| OpenUSD | OpenUSD (Universal Scene Description) is the scene-composition framework originating at Pixar and now governed by the Alliance for OpenUSD, definin... |
| OpenXR | OpenXR is the Khronos Group's royalty-free API standard for virtual and augmented reality, providing a common interface between applications and XR... |
| Personal Agent Protocol | Personal Agent Protocol ("Poppy") is an open protocol, announced by Sierra and Meta on 6 October 2026, for how a personal agent acting for one pers... |
| Phenopackets | Phenopackets is a GA4GH schema for exchanging phenotypic and clinical descriptions of an individual alongside genomic findings, standardized as ISO... |
| Platform Mesh | Platform Mesh is an open, multi-tenant developer platform built on kcp that establishes interoperability between service providers using the Kubern... |
| Postman Collections | A Postman Collection is a portable JSON artifacts that organizes one or more API requests—plus their params, headers, auth, scripts, and examples—s... |
| Postman Environments | Postman environments are collections of variables that let you easily switch between different configurations (like development, staging, and produ... |
| Problem Details for HTTP APIs | Problem Details for HTTP APIs, defined in RFC 7807 (now obsoleted by RFC 9457), is a standardized machine-readable format for carrying error detail... |
| Product Tree Standard | A draft standard from the Business Gardening framework for representing and exchanging a product as a portable snapshot with a fixed Product → Goal... |
| RAML | RAML (RESTful API Modeling Language) is a YAML-based specification for describing RESTful APIs in a structured, reusable format. It emphasizes patt... |
| RCS | Rich Communication Services is the GSMA's successor to SMS — an operator-standardised messaging protocol supporting rich media, read receipts, typi... |
| RDF | RDF (Resource Description Framework) is a W3C standard data model for describing resources as subject-predicate-object triples, providing a common,... |
| SLA4OAI | SLA4OAI is an open specification for describing service level agreements over REST APIs that are defined with OpenAPI. It extends an OpenAPI descri... |
| STAC | STAC is a specification for describing geospatial assets — satellite imagery, aerial photography, derived data products — so they can be discovered... |
| Schema.org | Schema.org is a collaborative, community-driven vocabulary (launched in 2011 by Google, Microsoft, Yahoo!, and Yandex) that defines shared types an... |
| Siren | Siren is a hypermedia specification for representing entities in JSON, including their properties, actions, and links. It enables clients to discov... |
| Sparkplug | Sparkplug is an Eclipse Foundation specification that defines topic namespace, payload structure and state management on top of MQTT, so that indus... |
| Specification | In the API world a specification is a machine-readable document that formally describes how an API behaves — its endpoints, operations, schemas, an... |
| Spectral | Spectral is a flexible, open-source tool designed for linting and validating API specifications such as OpenAPI, AsyncAPI, and JSON Schema files. I... |
| Standard Webhooks | Standard Webhooks is a set of open source tools and guidelines to send webhooks easily, securely and reliably. Webhooks are becoming increasingly p... |
| Swagger | An open-source framework for designing, building, documenting, and consuming RESTful web services. Swagger provides a specification (OpenAPI) and t... |
| Turbo EA Reference Catalog | The Turbo EA Reference Catalog is an open, MIT-licensed reference model for business architecture, covering three orthogonal artefacts — business c... |
| VAST | VAST — the Video Ad Serving Template — is the IAB Tech Lab XML specification that tells a video player what ad to play, where to fetch it, and whic... |
| Vacuum | RuleSets are how to configure vacuum to know which rules to run for each specification, and how it should evaluate those rules, and a RuleSet is a ... |
| W3C DID Resolution | DID Resolution defines how a decentralized identifier is resolved to its DID document, and how DID URLs are dereferenced, including the product-lev... |
| W3C Web of Things | The W3C Web of Things is a set of standards for describing IoT devices as web resources. Its central artifact, the Thing Description, is a JSON-LD ... |
| WADL | WADL (Web Application Description Language) is an XML-based specification for describing HTTP-based web applications and RESTful services. It model... |
| WDL | WDL is a human-readable workflow language that originated at the Broad Institute for genome analysis pipelines and is now governed by the OpenWDL c... |
| WSDL | WSDL (Web Services Description Language) is an XML-based format for describing the operations, messages, bindings, and endpoints of a SOAP web serv... |
| Web Standards | Web standards are the specifications and guidelines — largely from the W3C, WHATWG, and IETF — that define how core web technologies like HTML, CSS... |
| WebHDFS | Apache Hadoop's HTTP interface to HDFS, introduced in 2011 — a complete file-system vocabulary over REST (list, status, open with offset and length... |
| WebMCP | WebMCP lets a web page give AI agents JavaScript tools through a registerTool() API in the browser, so an agent can act on a site through functions... |
| XBRL | XBRL (eXtensible Business Reporting Language) is the XML-based standard for machine-readable business and financial reporting, used by securities r... |
| glTF | glTF is the Khronos Group's royalty-free specification for transmitting and loading 3D scenes and models, often described as "the JPEG of 3D". It d... |
| oEmbed | oEmbed is a simple format allowing a site to display embedded content from another site without parsing its markup — a consumer requests a URL agai... |
| x402 | x402 is an open payments protocol that uses HTTP's `402 Payment Required` status code to let a client pay for a resource in the course of requestin... |
| xDS | xDS is the family of discovery APIs that Envoy and other data planes use to receive their configuration dynamically. It defines Protobuf services f... |
| xRegistry | xRegistry defines an abstract model for managing metadata about resources and a REST-based interface for creating, modifying, deleting and discover... |