Specifications & Contracts
The machine-readable contracts APIs are defined, validated and governed with. 57 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,... |
| 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... |
| 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 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 ... |
| 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... |
| Arazzo | The Arazzo Specification is a community-driven, open standard within the OpenAPI Initiative (a Linux Foundation Collaborative Project). It defines ... |
| 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... |
| 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 ... |
| 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... |
| CloudEvents | CloudEvents is a CNCF specification for describing event data in a common, vendor-neutral format. It defines required and optional context attribut... |
| Collection+JSON | Collection+JSON is a JSON-based hypermedia media type for managing and querying collections of resources. It defines a standard document structure ... |
| 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... |
| 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.... |
| GraphQL | A query language for APIs and a runtime for executing those queries with existing data, providing a complete and understandable description of the ... |
| HAL | HAL (Hypertext Application Language) is a media-type specification for representing resources and their links in JSON or XML. It provides a simple,... |
| 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. ... |
| 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... |
| 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... |
| 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... |
| OData | OData (Open Data Protocol) is an OASIS and ISO/IEC-approved standard for building and consuming RESTful APIs, defining consistent conventions for q... |
| Open Collections | A modern, developer-first specification pioneered by Bruno for defining and sharing API collections. Designed for simplicity and collaboration. |
| 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 ... |
| 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... |
| 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... |
| 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... |
| 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... |
| 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 ... |
| WADL | WADL (Web Application Description Language) is an XML-based specification for describing HTTP-based web applications and RESTful services. It model... |
| 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... |
| 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... |