MCP, A2A + API integration

Connect agents, gateways and enterprise APIs

Vendor-neutral guidance on MCP servers and gateways, A2A agent interoperability, tool contracts, authentication and reliable integration.

Current specifications

Check these versions before you read any MCP or A2A tutorial. Material written before mid-2026 often describes sessions, server-initiated sampling and the older A2A message names.

Specification	Current version	Notable
Model Context Protocol	2026-07-28	Stateless core; no `initialize` or `Mcp-Session-Id`; Multi Round-Trip Requests; `Mcp-Method` / `Mcp-Name` headers; Roots, Sampling and Logging deprecated
Agent2Agent (A2A)	v1.0 (v1.0.1 patch)	JSON-RPC, gRPC and HTTP+JSON bindings; signed Agent Cards; `tenant` field; renamed operations (`SendMessage`, `GetTask`)
MCP authorization	OAuth 2.1 profile	Protected Resource Metadata, resource indicators, `iss` validation; Client ID Metadata Documents preferred over Dynamic Client Registration

Guides

🔌

MCP 2026-07-28 explained

What the stateless revision changes for servers, gateways and load balancers.

Read guide →

🚦

MCP gateway architecture

Per-tool authorization, filtered discovery, OAuth and a worked order-status example.

Read guide →

🧩

SAP Integration Suite MCP Gateway

Expose SAP APIs, iFlows and RFCs as governed MCP tools.

Read guide →

⇄

A2A for enterprise integration

Agent Cards, task lifecycle, push notifications and partner onboarding.

Read guide →

🗺

MCP vs A2A: the protocol stack

Where MCP, A2A, UCP, ACP and AP2 each fit.

Read guide →

🔗

API-centric integration

Predictable, managed interfaces to business capabilities, ready for agents.

Read guide →

MCP gateway landscape

Commonly evaluated gateways for governing MCP (and often A2A) traffic. Listed for orientation, not ranked or endorsed; confirm features with each vendor.

Gateway	Typical fit	Protocols
SAP Integration Suite MCP Gateway	SAP-centric landscapes; endorsed SAP pathway	MCP (federation on roadmap)
Amazon Bedrock AgentCore Gateway	AWS-hosted agents	MCP; A2A targets
Azure API Management	Microsoft / Entra ID estates	MCP tools
Kong AI Gateway	Existing Kong platforms	LLM, MCP, A2A
agentgateway (AAIF)	Open-source, multi-cloud	MCP, A2A
IBM ContextForge	Open-source federation	MCP, A2A
Microsoft MCP Gateway	Kubernetes, open-source	MCP

Reference architecture

Agent clients  ⇄ A2A ⇄  partner agents
      ↓
Identity · policy · approval
      ↓
MCP gateway ↔ MCP servers        (stateless, header-routed)
      ↓
API gateway / integration orchestration
      ↓
Enterprise apps, databases & event systems

An architectural pattern, not a specific vendor's implementation.