firebase-data-connect

PostgreSQL-backed GraphQL backend with auto-generated type-safe SDKs for web, mobile, and Flutter. Define GraphQL schema with @table decorators and relationships; Data Connect generates SQL and GraphQL operations automatically Write queries and mutations in GraphQL with filtering, ordering, pagination, and upsert support; transactions available via @transaction Secure operations with @auth levels (PUBLIC, USER, NO_ACCESS) and row-level controls using @check and @redact Generate type-safe SDKs for TypeScript, Kotlin, Swift, and Dart with nested data access and local emulator support for development

INSTALLATION
npx skills add https://github.com/firebase/agent-skills --skill firebase-data-connect
Run in your project or agent environment. Adjust flags if your CLI version differs.

SKILL.md

$2d

Key Tools for Validation

Rely on these two mechanisms to ensure project correctness:

  • Review GraphQL Schema: Both user-defined and generated extensions (in .dataconnect/schema/main/).
  • Validate Operations: Run npx -y firebase-tools@latest dataconnect:compile against the schema.

Operation Strategies: GraphQL vs. Native SQL

Always default to Native GraphQL. Native SQL lacks type safety and bypasses schema-enforced structures. Only use Native SQL when the user explicitly requests it or when the task requires advanced database features.

Strategy

When to use

Implementation

Native GraphQL (Default)

Almost all use cases. Standard CRUD, basic filtering/sorting, simple relational joins. Requires full type safety.

Auto-generated fields (movie_insert, movies). Strong typing and schema enforcement.

Native SQL (Advanced)

PostgreSQL extensions (e.g., PostGIS), window functions (RANK()), complex aggregations, or highly tuned sub-queries.

Raw SQL string literals via _select, _execute, etc. Requires strict positional parameters ($1). No type safety.

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 (which map to a Postgres schema).

Read reference/schema.md for:

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

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

Write the queries and mutations your client will use, including authorization logic. SQL Connect is secure by default.

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. Use _expr: "response.<prevStep>" to pass data between steps.

Read reference/security.md for authorization:

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

Read reference/realtime.md for real-time subscriptions:

  • @refresh directive for time-based polling and event-driven updates.
  • CEL conditions to scope refresh triggers precisely.

Read reference/native_sql.md for Native SQL operations:

  • Embedding raw SQL with _select, _selectFirst, _execute
  • Strict rules for positional parameters ($1, $2), quoting, and CTEs
  • Advanced PostgreSQL features (PostGIS, Window Functions)

3. Use type-safe SDK in your apps

Generate type-safe code for your client platform.

Configure SDK generation in connector.yaml:

connectorId: my-connector

generate:

  javascriptSdk:

    outputDir: "../web-app/src/lib/dataconnect"

    package: "@movie-app/dataconnect"

  kotlinSdk:

    outputDir: "../android-app/app/src/main/kotlin/com/example/dataconnect"

    package: "com.example.dataconnect"

  swiftSdk:

    outputDir: "../ios-app/DataConnect"

Generate SDKs:

npx -y firebase-tools@latest dataconnect:sdk:generate

For platform-specific instructions on how to use the generated SDKs, read:

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

Realtime Subscriptions

reference/realtime.md

@refresh, subscribe(), auto-refresh

Starter Templates

templates.md

CRUD, user-owned resources, many-to-many, SDK init

Deployment &#x26; CLI

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

Follow these patterns based on your current task:

How to initialize SQL Connect in a Firebase project

  • Understand the app idea. Ask clarification questions if unclear.
  • Run npx -y firebase-tools@latest init dataconnect.
  • Validate that the app template and generated SDK are setup.

How to build apps using SQL Connect locally

  • Start the emulator: npx -y firebase-tools@latest emulators:start --only dataconnect.
  • Write schema and operations.
  • Run npx -y firebase-tools@latest dataconnect:compile or npx -y firebase-tools@latest dataconnect:sdk:generate to

validate them.

  • Use the operations in your app and build it.

How to deploy SQL Connect to Cloud SQL

  • Run npx -y firebase-tools@latest deploy --only dataconnect.

Examples

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

examples.md.

For ready-to-use starter templates (CRUD, user-owned resources, many-to-many, YAML configs, SDK init), see templates.md.

BrowserAct

Let your agent run on any real-world website

Bypass CAPTCHA & anti-bot for free. Start local, scale to cloud.

Explore BrowserAct Skills →

Stop writing automation&scrapers

Install the CLI. Run your first Skill in 30 seconds. Scale when you're ready.

Start free
free · no credit card