APIs.json Reserved Words

These are the reserved type values for the properties array in an APIs.json index. Using these standard types ensures your API is correctly indexed by APIs.io and understood by tools that consume APIs.json files. Custom types are allowed using the X- prefix.

These reserved words apply to the type field of each entry in the properties array of an API entry, in the root-level common array, and in the prompts, rules, and workflows collections added in 0.21 (at both the top level and the API level). They are validated by the JSON Schema included with the specification.
Naming convention. Reserved type values are CamelCase with no spaces, no hyphens, and no underscores, and they are case-sensitive. Acronyms are kept in their conventional form (FAQ, SDKs, CLI, JSONSchema). Use TermsOfService, not Terms of Service or terms-of-service; use GettingStarted, not Getting Started. The corresponding API Commons property files use kebab-case filenames (terms-of-service.md) — that is a Jekyll filename convention, not the type value.

Technical Contracts

ALPS JSONForms DataContract Compare Evolution OpenAPI AsyncAPI JSONSchema GraphQLSchema WSDL WADL RAML Blueprint Swagger JSONStructure JSONLD JSONLDContext GraphQL Vocabulary SpectralRules Arazzo

Collections & Workspaces

PostmanCollection PostmanWorkspace InsomniaCollection BrunoCollection Specification

Onboarding & Access

Signup GettingStarted Documentation Authentication SignUp Login SDKs CLI Console Sandbox Versioning Training

Reference & Examples

UseCases Examples ApiExamples ErrorCodes FAQ Summary Tutorials Features APIReference Solutions Tools Careers

Plans & Operations

Plans Pricing RateLimits StatusPage ServiceLevelAgreement DeprecationPolicy

Legal & Compliance

TermsOfService InterfaceLicense PrivacyPolicy Security Compliance License Standards

Community & Support

Support Forums Blog BlogFeed Contact Community StackOverflow Slack Discord

Lifecycle

ChangeLog ReleaseNotes RoadMap

Integrations & Automation

Webhooks Integrations Services OpenAIPluginManifest ModelContextProtocol MockRestServer MockMCPServer AgentSkills LlmsText BackstageApi

Web & Portal

Website Portal DeveloperPortal About YouTube LinkedIn

Source Control & Social

GitHubOrg GitHubOrganization GitHubRepo GitHubRepository GitHubHttpUrl GitHubSshUrl GitHubIssues GitHubDiscussions Twitter X AlertsTwitterHandle

AI Prompts — the prompts collection (new in 0.21)

Prompt AgentPrompt PromptTemplate

Governance & Rules — the rules collection (new in 0.21)

SpectralRules Rules GovernanceRules

API Workflows — the workflows collection (new in 0.21)

Arazzo ServerlessWorkflow Workflow

FinOps & Sustainability

FinOps FinOpsFramework FocusBillingExport FocusConformanceReport FocusContractCommitments OpenCostSpecification OpenCostAllocationAPI UnitEconomics ChargebackPolicy TaggingPolicy InvoiceReconciliation SoftwareCarbonIntensity SCIReport GHGProtocolReport

Discovery & Catalog

PublicAPIsListing Review

Organisation & Context

BlogRSS CaseStudies ContactUs Crunchbase Events Facebook Instagram InvestorRelations Leadership Newsletter Newsroom ParentCompany Partners PressReleases Roadmap Sustainability Wikipedia

Privacy & Regulation

AccessibilityConformance AgeAssurance AITransparency BiometricDataPolicy DataResidency DataSubjectRequest ExitAssistance GlobalPrivacyControl IncidentNotification NoticeAndAction Subprocessors SupportLifetime TrainingDataSummary TransparencyReport

Agent & AI Surface

A2A AgentCard AgenticAccess AgentSkill LLMsTxt MCPClient MCPServer MCPServerCard X402

Security & Trust

APICatalog AuthorizationServerMetadata DomainSecurity OAuthScopes OpenIDConnect ProtectedResourceMetadata SecurityPolicy SecurityTxt TrustCenter VulnerabilityDisclosure WellKnown

Consent & Content Policy

ContentSignal

Authentication & Credentials

APIKey APIKeys

Standards & Conformance

Certification Conformance Standard

Licensing

Licensing

Operational & Developer Experience

APIOnboarding CodeExamples Components Conventions DataModel DeclineCodes Deprecation ErrorCatalog HelpCenter Idempotency KnowledgeBase Lifecycle MailingList Overlay Packages Playground Postman Protobuf Quickstart

Open Source & Supply Chain

Attestation CodeOfConduct ContributionGuide Contributors DockerImage HelmChart IssueTracker KubernetesOperator Maintainers Provenance Releases Repository SBOM SourceCode

Accepted alternate spellings

These spellings validate, because publishers already use them. Prefer the canonical name in new indexes.

A2AAgentCard API Documentation API Key API Keys APIDocumentation Changelog Connect Go SDK Connect Node.js SDK Connect Python SDK ContentSignals Deprecation Notice Deprecations Developer Portal Discourse ExecutiveTeam Forum GitHub GitHub Org Go SDK Help Center Java SDK JavaScript SDK JSON Schema JSON-LD Context Knowledge Base Knowledge Center KnowledgeCenter LeadershipTeam LLMsText LLMSTxt LlmsTxt Mailing List Mailing Lists MailingLists Management MCP News Node.js SDK OpenAPI Source OpenAPISource PHP SDK Postman Collection Press Privacy Privacy Policy Python SDK Reference Register Registration Ruby SDK SDK Security Policy Sign Up Source Code Spectral Spectral Rules SpectralRuleset Status Terms of Service Terms of Use TermsOfUse Trust x402

Custom Extensions

x-{name}

Any type prefixed with x- or X- is valid for custom, non-standard property types. Lower case is preferred. See section 3.9 of the specification for extensions elsewhere in a document.