Firebase Data Connect

Firebase Data Connect is a relational database service using Cloud SQL for PostgreSQL with GraphQL schema, auto-generated queries/mutations, and type-safe SDKs.

Project Structure

dataconnect/
├── dataconnect.yaml      # Service configuration
├── schema/
│   └── schema.gql        # Data model (types with @table)
└── connector/
    ├── connector.yaml    # Connector config + SDK generation
    ├── queries.gql       # Queries
    └── mutations.gql     # Mutations

Development Workflow

Follow this strict workflow to build your application. You must read the linked reference files for each step to understand the syntax and available features.

1. Define Data Model (schema/schema.gql)

Define your GraphQL types, tables, and relationships.

Read reference/schema.md for:

• @table, @col, @default
• Relationships (@ref, one-to-many, many-to-many)
• Data types (UUID, Vector, JSON, etc.)

2. Define Operations (connector/queries.gql, connector/mutations.gql)

Write the queries and mutations your client will use. Data Connect generates the underlying SQL.

Read reference/operations.md for:

• Queries: Filtering (where), Ordering (orderBy), Pagination (limit/offset).
• Mutations: Create (_insert), Update (_update), Delete (_delete).
• Upserts: Use _upsert to "insert or update" records (CRITICAL for user profiles).
• Transactions: use @transaction for multi-step atomic operations.

3. Secure Your App (connector/ files)

Add authorization logic closely with your operations.

Read reference/security.md for:

• @auth(level: ...) for PUBLIC, USER, or NO_ACCESS.
• @check and @redact for row-level security and validation.

4. Generate & Use SDKs

Generate type-safe code for your client platform.

Read reference/sdks.md for:

• Android (Kotlin), iOS (Swift), Web (TypeScript), Flutter (Dart).
• How to initialize and call your queries/mutations.
• Nested Data: See how to access related fields (e.g., movie.reviews).

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Feature Capability Map

If you need to implement a specific feature, consult the mapped reference file:

Feature	Reference File	Key Concepts
Data Modeling	reference/schema.md	@table, @unique, @index, Relations
Vector Search	reference/advanced.md	Vector, @col(dataType: "vector")
Full-Text Search	reference/advanced.md	@searchable
Upserting Data	reference/operations.md	_upsert mutations
Complex Filters	reference/operations.md	_or, _and, _not, eq, contains
Transactions	reference/operations.md	@transaction, response binding
Environment Config	reference/config.md	dataconnect.yaml, connector.yaml

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Deployment & CLI

Read reference/config.md for deep dive on configuration.

Common commands (run from project root):

# Initialize Data Connect
npx -y firebase-tools@latest init dataconnect

# Start local emulator
npx -y firebase-tools@latest emulators:start --only dataconnect

# Generate SDK code
npx -y firebase-tools@latest dataconnect:sdk:generate

# Deploy to production
npx -y firebase-tools@latest deploy --only dataconnect

Examples

For complete, working code examples of schemas and operations, see examples.md.