{
  "job_id": "job-0002",
  "received_via": "A2A (simulated inbound)",
  "skill_invoked": "competitive_scan",
  "task": "A2A vs MCP in 2026: difference, adoption, when to use which",
  "status": "completed",
  "completed_at_utc": "2026-06-16T16:22:42Z",
  "deliverable": {
    "summary": "MCP(Anthropic)=agent-to-tool層, A2A(Google)=agent-to-agent協調層。競合ではなく補完。2層スタック(MCP=縦のツール統合 / A2A=横のエージェント協調)が2026エンタープライズの既定アーキ。両者2025-12にLinux Foundation配下のAgentic AI Foundation(AAIF)へ(共同創設: OpenAI/Anthropic/Google/Microsoft/AWS/Block)。",
    "facts": [
      "MCP: 2026-02時点 月9,700万SDK DL, 10,000+稼働サーバ, 全主要AI(Anthropic/OpenAI/Google/Microsoft/Amazon)採用",
      "A2A: Google 2025-04公開, 50+エンタープライズ参加, 2026初頭にv1.0(gRPC/署名付きAgent Card/マルチテナント)",
      "使い分け: 1エージェント+ツール=MCP / 複数エージェント協調・委譲=A2A / 複合=併用",
      "支払い連携: MCP+x402, A2A+AP2",
      "未解決: クロスプロトコル相互運用(A2A→ACP委譲は未対応), Q3-2026にMCP/A2A共同仕様が初の橋渡し"
    ],
    "implication_for_sasame": "SaSameは MCP(ツール提供) は既に持つ。A2A(他エージェントからの受注口)を Agent Card で discoverable にするのが次。OAuth2.1+Resource Indicators / Streamable HTTP / Agent Card互換discovery が production既定。",
    "sources": ["dev.to MCP vs A2A 2026","digitalocean a2a-vs-mcp","intuz MCP vs A2A","zylos.ai interoperability 2026","optinampout MCP vs A2A vs ACP"]
  },
  "x402_invoice": {"scheme":"x402","amount":"0.50","currency":"USDC","network":"base","pay_to":"0xfAd6bf2B441e6d3C2891994B823Fe2d8B421094c","note":"DEMO"}
}