Capabilities deep-dive

Everything you need
to master your contracts

APIHUB catalogs machine-readable contracts — REST and GraphQL APIs, event APIs, database schemas (DDLAPI), and MCP tool surfaces — with shared versioning, diff, and governance.

Contract catalog

Supported Contracts & API Types

Classic API types (REST, GraphQL, AsyncAPI) remain first-class for operations. Newer contract types — DDLAPI and MCP — publish, version, search, compare, and export alongside them in the same package model.

Contract / API Type Backend Build K8s Discovery UI / Portal Diff Doc Viewer Linter
API OpenAPI 3.0 / 3.1
✓
✓
✓
✓
✓
✓
✓ Spectral + AI
API Swagger 2.0
✓ via conv.
✓ → OAS3
✓
✓
✓ → OAS3
✓
✓ Spectral + AI
API GraphQL
✓
✓
✓ introspect
✓
✓ apiKind
✓
✓ Spectral
API AsyncAPI 3.0
✓
✓
✓
✓
✓
✓
✓ Spectral
Contract DDLAPI (DB schemas)
✓ contracts
✓ ddlBuilder
—
✓ search + dashboards
✓ table Diff View
✓ tables
—
Contract MCP contracts
✓ contracts
✓ mcpBuilder
—
✓ search + dashboards
—
✓ tools / raw
—
Stub Protobuf / gRPC
✓
✓
— — — — —
Docs Markdown Docs
◑ storage
✓
✓
✓ + Mermaid
—
✓
—
Legend: ✓ Supported ◑ Partial — Not applicable Badges: API = operation API type · Contract = catalog contract type

MCP server (tools for agents/IDEs at /api/v1/mcp/) is separate from MCP contracts stored in the catalog. Both ship in current releases.

Find Any API in Seconds

Powerful global search across all operations, documents, and packages. Navigate the full hierarchy — workspace → group → package → version — with rich filters.

  • Search across REST operations, GraphQL queries, AsyncAPI channels, DDL tables, and MCP tools
  • Browse DDLAPI and MCP contracts in the same package hierarchy and on dashboards
  • Deep-link directly into the doc view or package summary
  • Filter by audience, tags, API kind, deprecation, and multiple version statuses
apihub.example.com/portal/search
GET /users/{id} — user profile
GET /api/v1/users/{id} User Service REST
GET /api/v1/users/{id}/profile Profile Service REST
query getUserById(id: ID!): User GraphQL Gateway GraphQL
GET /v2/customers/{customerId} CRM Service REST

Detect Breaking Changes Automatically

Version-to-version and operation-level diffs with automated classification. Compare versions, revisions, or REST path groups — including AsyncAPI and DDLAPI table schemas — with export to Excel for compliance.

  • Breaking / Semi-Breaking / Deprecated / Non-Breaking / Annotation severity
  • Compare versions or revisions across REST, GraphQL, AsyncAPI, and DDLAPI (table schema Diff View)
  • GraphQL no-BWC and experimental apiKind use the same change rules as REST
  • Export REST, GraphQL, AsyncAPI, DDL, and MCP change lists to Excel
API Changes comparison view showing breaking change classification
Product screenshot — click to enlarge
API Changes comparison view showing breaking change classification

Enforce API Standards Automatically

Multi-linter governance with Spectral rulesets and AI-powered analysis. Inline spec highlighting shows exactly which line violates a rule.

  • Spectral engine with configurable custom rulesets per API type
  • AI linter for OpenAI-powered quality recommendations
  • Inline problem highlighting directly in the spec viewer
  • Per-ruleset activation history and downloadable reports
API Quality tab showing multi-linter results with inline spec highlighting
Product screenshot — click to enlarge
API Quality tab showing multi-linter results with inline spec highlighting

Discover APIs Running in Your Clusters

Deploy lightweight agents to remote Kubernetes clusters. Agents automatically discover REST, GraphQL, and AsyncAPI services and promote specs into the central catalog.

  • Pluggable discovery runners: REST, GraphQL, AsyncAPI, JSON Schema
  • Limit a run to specified services, or keep namespace-wide discovery
  • PAT authentication for agents; heartbeat health checks with snapshot TTL cleanup
  • One-click promotion from agent snapshot to the governed portal catalog
Kubernetes API discovery visualization showing cluster pods and API spec detection

Try APIs Without Leaving the Portal

Spec-driven REST playground directly in the doc view. Pick server, fill parameters from the spec schema, send requests, and inspect responses.

  • Spec-driven parameter and body filling from OpenAPI schema
  • Multiple server support with custom server override
  • Agent Proxy for in-cluster testing via the K8s agent network
  • Server selection and custom URLs persisted in local storage
REST Playground sidebar showing request builder and response viewer

First-Class AsyncAPI Support

AsyncAPI 3.0 treated as a first-class citizen — full doc rendering, SEND/RECEIVE badges, channel addressing, Kafka/AMQP bindings, and complete diff engine integration.

  • AsyncAPI 3.0 operation rendering with SEND/RECEIVE semantics
  • Kafka, AMQP bindings at operation, channel, and message level
  • Breaking change detection, classification, and Diff View in Doc Viewer
  • Agent-based discovery of AsyncAPI services in Kubernetes clusters
AsyncAPI DocView showing SEND/RECEIVE operations with channel and binding details

Beyond API Types: Catalog Contracts

Publish DDLAPI database schemas and MCP tool/resource/prompt documents as first-class contracts in the same package versions. The Portal covers search, dashboards, changelog, and export — not only browse.

  • DDLAPI: table viewer, changelog, dashboards, and side-by-side schema Diff View
  • MCP contracts: configure endpoints before publish, then search, compare, and export
  • Shared build pipeline via ddlBuilder / mcpBuilder; document apiKind persisted on publish
  • MCP server for IDEs remains separate: it queries the catalog; it is not the contract type
Contract types — DDLAPI and MCP alongside classic API types