Firebase SQL Connect Streaming Lands in the JavaScript SDK

Firebase shipped streaming support for SQL Connect in the JavaScript SDK this month, making the @refresh directive (announced at Cloud Next in April) usable in web apps for the first time.

Key Takeaways

• JS SDK streaming support for SQL Connect is rolling out and will reach all projects by the end of June 2026 (Firebase JS SDK release notes).
• Eight new expression functions landed alongside streaming: parent, timestamp_trunc, timestamp_diff, timestamp_extract, nor, switchOn, ifNull, and coalesce.
• Any SQL Connect query can become a live subscription. The SDK pushes updates when backend data changes, without polling.
• Streaming operations are billed at the same rate as standard queries: $0.90 per million operations (Firebase pricing).

What the @refresh directive does

SQL Connect’s realtime subscriptions bind a query to a stream of results. Annotate a query with @refresh and the client SDK holds an open connection, applying incremental updates as they arrive:

query GetLeaderboard @refresh {
  scores(orderBy: { score: DESC }, limit: 10) {
    player
    score
  }
}

Refresh behavior is configurable: trigger on a time interval, or tie it to a specific mutation so a score write only updates the leaderboard subscribers that care about it. The SQL Connect SDK also ships query-level and entity-level caching. The app shows cached data immediately, then replaces it when the subscription delivers fresh results (Realtime PostgreSQL: From Data Connect to SQL Connect, Firebase Blog, April 2026).

New expression functions

Eight functions joined the SQL Connect expression language in this release. timestamp_trunc and timestamp_diff cover date bucketing, specifically the hourly or daily groupings common in dashboards. switchOn provides multi-branch conditional logic, avoiding chains of nested ifNull calls. coalesce returns the first non-null value from a list, useful for fallback lookups across normalized tables. parent navigates document hierarchy in a single expression.

All eight work in both standard queries and @refresh-annotated subscriptions.

Availability

The rollout is gradual. If the streaming subscription API isn’t in your project yet, it should arrive before July 1. SQL Connect requires a Cloud SQL Postgres backend; Realtime Database and Firestore are unaffected. The feature is part of the broader SQL Connect product that replaced Firebase Data Connect at Cloud Next 2026; existing Data Connect project APIs are unchanged (Firebase SQL Connect).