---
title: "firebase 13.0.0, a new major version: 2026-10-07 | Harbyn"
description: "firebase 13.0.0, a new major version, announced Oct 7, 2026."
canonical: "https://harbyn.com/changes/firebase/2026-10-07-firebase-13-0-0"
last-updated: 2026-10-07
---

# firebase 13.0.0, a new major version

Markdown version of <https://harbyn.com/changes/firebase/2026-10-07-firebase-13-0-0>.

Breaking change - Firebase. medium severity. In effect.

Firebase JavaScript SDK 13.0.0 has breaking changes in AI Logic: VertexAIBackend and other deprecated APIs are removed, TemplateGenerativeModel methods take a single TemplateRequest, Part becomes a discriminated union, ChatSession is exported as an interface, and the default hybrid in-cloud model is now gemini-3.5-flash-lite. Cloud Firestore adds BSON types.

## Facts

| Fact | Value |
| --- | --- |
| Vendor | [Firebase](https://harbyn.com/vendors/firebase.md) |
| Kind | Breaking change |
| Severity | medium |
| Status | In effect |
| Announced | Oct 7, 2026 |
| Added to Harbyn | Oct 7, 2026 |
| Lead time | No dated deadline |
| Packages | `npm: firebase <13.0.0` |
| Vendor page | <https://github.com/firebase/firebase-js-sdk/releases/tag/firebase%4013.0.0> |
| Review | Reviewed by a person, extracted by a deterministic parser |

## Find it in your code

```sh
npx harbyn scan
```

The scanner reads your repository on your machine and reports every file and line that uses the identifiers above. Nothing leaves your machine.

## Sources

Where this event comes from: the page we read, when we read it, and the hash of that snapshot.

- <https://api.github.com/repos/firebase/firebase-js-sdk/releases?per_page=20> (release, fetched 2026-10-07 23:09 UTC, sha256 `8e81540f01beb46980ee4ce573e937502a69b38dce370e7eb55780e632888f69`)

## Related changes

### More from Firebase

- [AI Logic in JavaScript SDK 13.0.0 exports ChatSession as an interface, not a class](https://harbyn.com/changes/firebase/2026-10-07-chatsession-class-replaced-by-interface.md) (Breaking change, announced Oct 7, 2026)
- [AI Logic in JavaScript SDK 13.0.0 makes gemini-3.5-flash-lite the default hybrid in-cloud model](https://harbyn.com/changes/firebase/2026-10-07-default-hybrid-in-cloud-model-changed.md) (Behavior change, announced Oct 7, 2026)
- [AI Logic in JavaScript SDK 13.0.0 removes previously deprecated APIs](https://harbyn.com/changes/firebase/2026-10-07-deprecated-apis-removed.md) (Breaking change, announced Oct 7, 2026)
- [Remote Config in JavaScript SDK 13.0.0 stops false CONFIG\_UPDATE\_STREAM\_ERROR events on backgrounding](https://harbyn.com/changes/firebase/2026-10-07-expected-background-connection-closes-handled-differently.md) (Behavior change, announced Oct 7, 2026)

### Changes at other vendors

- [Amazon Selling Partner API: October listing attribute usage and enumeration value updates](https://harbyn.com/changes/amazon-sp-api/2026-10-14-sp-api-updates-new-listings-items-api-ivp-values-in-eu5-jp-and-ca-stores-oct-2.md) (effective Oct 26, 2026)
- [Supabase: four CBC-mode TLS 1.2 cipher suites will be removed from project HTTP APIs](https://harbyn.com/changes/supabase/2026-10-12-an-outdated-subset-of-tls-1-2-ciphers-will-be-disabled-on-project-http-apis.md) (effective Nov 10, 2026)
- [Google Workspace APIs: OAuth clients must be marked as agentic to call Google Workspace MCP servers](https://harbyn.com/changes/google-workspace/2026-10-12-oauth-clients-must-be-marked-as-agentic-to-call-google-workspace-mcp-servers.md) (effective Nov 11, 2026)
- [Bitbucket Cloud API: Git Credential Manager upgrade required for OAuth 2.0 Git authentication](https://harbyn.com/changes/bitbucket/2026-10-13-git-credential-manager-upgrade-required-for-oauth-2-0-git-authentication.md) (effective Nov 30, 2026)

[All upcoming deadlines](https://harbyn.com/deadlines.md)