Antigravity × Firebase Data Connect：GraphQL型安全APIをAIで最速構築する実践アーキテクチャ

# dataconnect/schema/schema.gql
 
type User @table {
  id: UUID\! @col(name: "user_id") @default(expr: "uuidV4()")
  email: String\! @col(dataType: "varchar(255)") @unique
  displayName: String\! @col(name: "display_name", dataType: "varchar(100)")
  createdAt: Date\! @col(name: "created_at") @default(expr: "request.time")
  posts: [Post\!]\! @hasMany(foreignKey: "author_id")
}
 
type Post @table {
  id: UUID\! @col(name: "post_id") @default(expr: "uuidV4()")
  title: String\! @col(dataType: "varchar(500)")
  content: String\! @col(dataType: "text")
  published: Boolean\! @default(value: false)
  authorId: UUID\! @col(name: "author_id")
  author: User\! @belongsTo(foreignKey: "author_id")
  tags: [Tag\!]\! @manyToMany(joinTable: "PostTag")
  createdAt: Date\! @col(name: "created_at") @default(expr: "request.time")
  updatedAt: Date @col(name: "updated_at")
}
 
type Tag @table {
  id: UUID\! @col(name: "tag_id") @default(expr: "uuidV4()")
  name: String\! @col(dataType: "varchar(50)") @unique
  posts: [Post\!]\! @manyToMany(joinTable: "PostTag")
}

# dataconnect/connector/queries.gql
 
# 公開済み投稿の一覧（ページネーション付き）
query ListPublishedPosts($limit: Int, $offset: Int) @auth(level: PUBLIC) {
  posts(
    where: { published: { eq: true } }
    orderBy: [{ createdAt: DESC }]
    limit: $limit
    offset: $offset
  ) {
    id
    title
    createdAt
    author {
      id
      displayName
    }
    tags {
      name
    }
  }
}
 
# ユーザーの全投稿（認証必須）
query GetUserPosts($userId: UUID\!) @auth(level: USER) {
  posts(
    where: {
      authorId: { eq: $userId }
      # 自分の投稿のみアクセス可能
      _and: [{ authorId: { eq_expr: "auth.uid" } }]
    }
    orderBy: [{ createdAt: DESC }]
  ) {
    id
    title
    published
    createdAt
    updatedAt
  }
}
 
# 投稿詳細（公開済みのみ、または自分の投稿）
query GetPostDetail($postId: UUID\!) @auth(level: PUBLIC) {
  post(
    id: $postId
    where: {
      _or: [
        { published: { eq: true } }
        { authorId: { eq_expr: "auth.uid" } }
      ]
    }
  ) {
    id
    title
    content
    published
    createdAt
    updatedAt
    author {
      id
      displayName
    }
    tags {
      id
      name
    }
  }
}

# dataconnect/connector/mutations.gql
 
# 投稿の新規作成（認証必須）
mutation CreatePost($title: String\!, $content: String\!, $tagIds: [UUID\!]) @auth(level: USER) {
  post_insert(data: {
    title: $title
    content: $content
    authorId_expr: "auth.uid"
    tags: { connect: $tagIds }
  }) {
    id
    title
    createdAt
  }
}
 
# 投稿の更新（オーナーのみ）
mutation UpdatePost($postId: UUID\!, $title: String, $content: String, $published: Boolean) @auth(level: USER) {
  post_update(
    id: $postId
    data: {
      title: $title
      content: $content
      published: $published
      updatedAt_expr: "request.time"
    }
    where: { authorId: { eq_expr: "auth.uid" } }
  ) {
    id
    title
    published
    updatedAt
  }
}
 
# 投稿の削除（オーナーのみ）
mutation DeletePost($postId: UUID\!) @auth(level: USER) {
  post_delete(
    id: $postId
    where: { authorId: { eq_expr: "auth.uid" } }
  )
}

// src/lib/dataconnect.ts
 
import {
  connectDataConnectEmulator,
  getDataConnect,
} from "firebase/data-connect";
import { connectorConfig } from "@firebasegen/my-app-connector";
 
// 開発環境ではエミュレーターに接続
const dc = getDataConnect(connectorConfig);
if (process.env.NODE_ENV === "development") {
  connectDataConnectEmulator(dc, "localhost", 9399);
}
 
export { dc };

// src/app/posts/page.tsx（Next.js App Router の例）
 
import {
  executeQuery,
  listPublishedPostsRef,
} from "@firebasegen/my-app-connector";
import { dc } from "@/lib/dataconnect";
 
async function getPosts(limit = 10, offset = 0) {
  try {
    const result = await executeQuery(listPublishedPostsRef(dc, { limit, offset }));
    return result.data.posts;
  } catch (error) {
    // Data Connect のエラーは FirebaseError 型
    if (error instanceof Error && error.message.includes("permission")) {
      console.error("アクセス権限エラー:", error.message);
      return [];
    }
    throw error;
  }
}
 
export default async function PostsPage() {
  const posts = await getPosts();
  return (
    <ul>
      {posts.map((post) => (
        <li key={post.id}>
          <a href={`/posts/${post.id}`}>{post.title}</a>
          <span>{post.author.displayName}</span>
        </li>
      ))}
    </ul>
  );
}

# ❌ 危険：ログイン済みなら誰でも他人の投稿を削除できる
mutation DeletePost($postId: UUID\!) @auth(level: USER) {
  post_delete(id: $postId)
}
 
# ✅ 安全：自分の投稿しか削除できない
mutation DeletePost($postId: UUID\!) @auth(level: USER) {
  post_delete(
    id: $postId
    where: { authorId: { eq_expr: "auth.uid" } }
  )
}

// src/lib/auth-dataconnect.ts
 
import { getAuth, onAuthStateChanged } from "firebase/auth";
import { getDataConnect, setInitialUserToken } from "firebase/data-connect";
import { connectorConfig } from "@firebasegen/my-app-connector";
 
const auth = getAuth();
const dc = getDataConnect(connectorConfig);
 
// Firebase Auth の状態変化を Data Connect に反映する
onAuthStateChanged(auth, async (user) => {
  if (user) {
    const token = await user.getIdToken();
    await setInitialUserToken(dc, token);
  } else {
    // ログアウト時はトークンをクリア
    await setInitialUserToken(dc, undefined);
  }
});

// src/app/actions/posts.ts
 
"use server";
 
import { revalidatePath } from "next/cache";
import { executeMutation, createPostRef } from "@firebasegen/my-app-connector";
import { dc } from "@/lib/dataconnect";
 
export async function createPost(title: string, content: string) {
  try {
    const result = await executeMutation(
      createPostRef(dc, { title, content })
    );
    // Next.js のキャッシュを無効化
    revalidatePath("/posts");
    return { success: true, post: result.data.post_insert };
  } catch (error) {
    console.error("投稿作成エラー:", error);
    return { success: false, error: "投稿の作成に失敗しました" };
  }
}

import { z } from "zod";
 
const uuidSchema = z.string().uuid("無効なIDフォーマットです");
 
export async function getPost(postId: string) {
  // バリデーション
  const validatedId = uuidSchema.parse(postId);
  
  try {
    const result = await executeQuery(
      getPostDetailRef(dc, { postId: validatedId })
    );
    return result.data.post;
  } catch (error) {
    if (error instanceof z.ZodError) {
      throw new Error("無効なリクエストです");
    }
    throw error;
  }
}

function formatJST(dateString: string): string {
  return new Intl.DateTimeFormat("ja-JP", {
    timeZone: "Asia/Tokyo",
    year: "numeric",
    month: "2-digit",
    day: "2-digit",
    hour: "2-digit",
    minute: "2-digit",
  }).format(new Date(dateString));
}

# 本番環境へのデプロイ
firebase deploy --only dataconnect
 
# スキーママイグレーション（破壊的変更がある場合）
firebase dataconnect:sql:migrate --force
 
# デプロイ前のドライラン（推奨）
firebase dataconnect:sql:migrate --dry-run

// カスタム MCP サーバー：Data Connect をAIエージェントに公開する例
// mcp-server/src/tools/dataconnect.ts
 
import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { executeQuery, listPublishedPostsRef } from "@firebasegen/my-app-connector";
import { dc } from "../lib/dataconnect.js";
 
export function registerDataConnectTools(server: Server) {
  server.setRequestHandler("tools/call", async (request) => {
    if (request.params.name === "get_recent_posts") {
      const { limit = 5 } = request.params.arguments as { limit?: number };
      
      try {
        const result = await executeQuery(
          listPublishedPostsRef(dc, { limit })
        );
        return {
          content: [{
            type: "text",
            text: JSON.stringify(result.data.posts, null, 2)
          }]
        };
      } catch (error) {
        return {
          content: [{
            type: "text",
            text: `エラー: ${error instanceof Error ? error.message : "不明なエラー"}`
          }],
          isError: true
        };
      }
    }
  });
}