API Specifications
Meta-index of the specification languages used to describe APIs, events, schemas, and service interfaces across the modern API landscape. This repo is the META layer above the topical repos that profile each individual specification — it catalogs every major HTTP, event-driven, schema, and service interface specification along with its current version, governing body, license, and tooling ecosystem.
More than an index entry, but the surface is still mostly links rather than artifacts — the cohort most likely to move a full band from modest, well-targeted work.
API Evangelist profiles API Specifications the way a machine reads it — 49 machine-readable artifacts across 13 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — API Specifications scores 27.7/100 (emerging), with a separate agent-readiness read of 0/100 (human only). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile API Specifications
Each block below is one kind of artifact we hold for API Specifications. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 13
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
OpenAPI Specification (OAS)
The OpenAPI Specification (formerly Swagger) is the dominant industry standard for describing HTTP-based RESTful APIs. OAS describes endpoints, operations, parameters, request/r...
AsyncAPI Specification
AsyncAPI is the open standard for describing event-driven and message-driven APIs across protocols such as Kafka, AMQP, MQTT, WebSocket, NATS, and SNS/SQS. AsyncAPI 3.0 (Decembe...
JSON Schema
JSON Schema is a declarative language for annotating and validating JSON documents. It is the foundational schema language for most modern API specifications (OpenAPI 3.1, Async...
JSON Structure
JSON Structure is an emerging open specification that extends and complements JSON Schema with a clearer, more code-generation-friendly type system designed for data contracts a...
GraphQL SDL
GraphQL is a query language and runtime for APIs, defined by the GraphQL Specification. The GraphQL Schema Definition Language (SDL) is the declarative format used to define typ...
gRPC and Protocol Buffers
gRPC is a high-performance RPC framework using HTTP/2 and Protocol Buffers (Protobuf) as its IDL and wire format. Service definitions are written in .proto files. gRPC is a CNCF...
Smithy
Smithy is an open-source IDL and code-generation framework for defining services and SDKs, created and maintained by AWS. It is protocol-agnostic (HTTP REST, AWS JSON, MQTT, RPC...
TypeSpec
TypeSpec (formerly Cadl) is a language for describing API shapes developed by Microsoft. TypeSpec definitions emit OpenAPI 3.x, JSON Schema, Protobuf, and other artifacts, and s...
RAML (RESTful API Modeling Language)
RAML is a YAML-based modelling language for RESTful APIs, originally created by Mulesoft. RAML 1.0 (2016) is the current stable specification. RAML governance has effectively co...
API Blueprint
API Blueprint is a Markdown-based specification language for describing web APIs, originally created by Apiary (acquired by Oracle). The spec is MIT licensed but development eff...
WSDL / SOAP
The Web Services Description Language (WSDL) is the historical XML-based interface definition language for SOAP web services. WSDL 1.1 (2001) is the most widely deployed version...
JSON-RPC 2.0
JSON-RPC 2.0 is a stateless, light-weight remote procedure call (RPC) protocol encoded in JSON. It is widely used in blockchain/Web3 APIs (Ethereum, Bitcoin), IDE language serve...
Tinybird API Spec
The Tinybird API specification is a vendor-defined, declarative format for describing analytics endpoints (pipes), data sources, and parameters backed by ClickHouse. It is docum...
Scroll within the panel for all 13 ·
GraphQL 1
Where a provider ships GraphQL, the schema is the contract. We profile it alongside the REST surface so the whole interface is legible in one place.
GraphQL schemas published by this provider.
API Specifications GraphQL API
GraphQL is a query language and runtime for APIs, defined by the GraphQL Specification. The GraphQL Schema Definition Language (SDL) is the declarative format used to define typ...
GRAPHQLFeatures 6
The notable capabilities this provider advertises, captured as structured features so they can be searched and compared instead of read one landing page at a time.
Notable capabilities this provider offers.
HTTP Request/Response Specifications
Languages for describing synchronous HTTP APIs — paths, methods, parameters, request bodies, responses, and security. Includes OpenAPI, RAML, API Blueprint, and historically WSDL.
Event-Driven Specifications
Languages for describing message-driven and event-driven APIs across brokers and protocols. Primarily AsyncAPI 3.x, plus protocol-specific schemas (Avro, Protobuf) used in concert.
Service Interface Definition Languages (IDLs)
Languages that define language-agnostic service contracts intended for code generation across clients and servers. Includes gRPC/Protobuf, Smithy, TypeSpec, and historically WSDL.
Schema Languages
Languages for describing data shapes independent of a specific transport. Includes JSON Schema (the de facto standard, embedded in OpenAPI and AsyncAPI) and the emerging JSON St...
RPC Protocol Specifications
Specifications for remote procedure call protocols. Includes JSON-RPC 2.0 (used heavily in blockchain and LSP) and gRPC for high-performance RPC.
Vendor-Defined Specifications
Vendor-specific specification formats that govern modern API products (e.g. Tinybird pipes). These often emit OpenAPI as a derived artifact while keeping a higher-level domain m...
Semantic Vocabularies 1
JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.
JSON-LD contexts and semantic vocabularies used across these APIs.
Specifications Context
JSON-LDSpectral Rules 1
Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.
API Specifications API Rules
SPECTRALJSON Schema 1
Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.
Standalone JSON Schema definitions for this provider's data models.
SpecificationRecord
JSON SCHEMAJSON Structure 1
JSON Structure captures the data shapes in a form built for tooling — a complement to JSON Schema that keeps the model machine-legible.
JSON Structure definitions describing this provider's data shapes.
Specification Record Structure
JSON STRUCTUREExamples 13
Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.
Example request and response payloads for these APIs.
Api Blueprint Example
EXAMPLEAsyncapi Example
EXAMPLEGraphql Example
EXAMPLEGrpc Protobuf Example
EXAMPLEJson Rpc Example
EXAMPLEJson Schema Example
EXAMPLEJson Structure Example
EXAMPLEOpenapi Example
EXAMPLERaml Example
EXAMPLESmithy Example
EXAMPLETinybird Example
EXAMPLETypespec Example
EXAMPLEWsdl Soap Example
EXAMPLEScroll within the panel for all 13 ·
Security Posture 1
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Use Cases 5
What developers actually build with this provider — captured so the catalogue answers 'what is this for', not just 'what does this expose'.
What developers build with this provider.
Specification Discovery and Cataloging
Maintaining an enterprise inventory of specifications used across internal and partner APIs, mapped to their governing bodies and tooling.
Multi-Format Code Generation
Choosing or layering specifications (TypeSpec or Smithy as a high-level model emitting OpenAPI, JSON Schema, and Protobuf) to generate SDKs across protocols.
Event-Driven Architecture Contracts
Using AsyncAPI alongside Avro/Protobuf to define event schemas, channels, and operations for streaming and message-driven systems.
Governance and Linting Across Specs
Applying Spectral or other linting frameworks against OpenAPI, AsyncAPI, and JSON Schema artifacts as part of an API governance program.
Legacy SOAP/WSDL Modernization
Migrating legacy WSDL/SOAP interfaces to OpenAPI-described REST or gRPC service contracts as part of modernization initiatives.
Integrations 6
Pre-built integrations with other platforms tell you where this provider already fits in a stack.
Pre-built integrations with other platforms and tools.
Spectral
Open-source linting engine (Stoplight) for OpenAPI, AsyncAPI, and JSON Schema. The de facto governance engine across HTTP and event-driven specs.
Redocly CLI
Open-source CLI for linting, bundling, and rendering OpenAPI specs; enforces style guides and integrates with CI.
AsyncAPI Generator
Template-driven code and documentation generator for AsyncAPI specs across languages and brokers.
Protoc / Buf
The canonical Protobuf compiler and Buf's modern toolchain for linting, breaking-change detection, and code generation against .proto files.
Smithy CLI
AWS-maintained CLI for compiling Smithy models and generating OpenAPI, JSON Schema, and SDK artifacts.
TypeSpec Compiler
Microsoft-maintained compiler that emits OpenAPI 3, JSON Schema, Protobuf, and other artifacts from TypeSpec sources.
Resources
Every other property we hold for API Specifications — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Documentation 1
Reference material describing how the API behaves
Design & Contract 3
Pagination, idempotency, versioning, errors, and events
Build 11
SDKs, sample code, and the tooling you integrate with
Scroll within the panel for all 11 ·
Access & Security 1
Authentication, authorization, and security posture
Company 1
The organization behind the API
← All providers · Data indexed from github.com/api-evangelist/specifications · machine-readable index on apis.io