--- title: "Legacy Vertex AI initialization syntax removed from Firebase AI Logic SDKs: 2026-10-15 | Harbyn" description: "Legacy Vertex AI initialization syntax removed from Firebase AI Logic SDKs, effective Oct 15, 2026; replacement: agentPlatform, AgentPlatformBackend." canonical: "https://harbyn.com/changes/firebase/2026-10-15-legacy-vertex-ai-initialization-syntax-removed-from-firebase-ai-logic-sdks" last-updated: 2026-10-25 --- # Legacy Vertex AI initialization syntax removed from Firebase AI Logic SDKs Markdown version of . Breaking change - Firebase. medium severity. In effect. History: recorded after the fact. The latest Firebase AI Logic SDK versions have removed the legacy Vertex AI initialization syntax in favor of Agent Platform syntax. Apps using the Agent Platform Gemini API must update their initialization syntax when upgrading. The new backend defaults to global instead of us-central1; specify a location explicitly if needed. The deadline passed on Oct 15, 2026. ## Facts | Fact | Value | | --- | --- | | Vendor | [Firebase](https://harbyn.com/vendors/firebase.md) | | Kind | Breaking change | | Severity | medium | | Status | In effect | | Announced | Oct 15, 2026 | | Effective | Oct 15, 2026 | | Added to Harbyn | Oct 25, 2026 | | Lead time | Recorded after the fact: added 10 days after the deadline | | Symbols | `vertexAI`, `VertexAIBackend` | | Replacement | `agentPlatform`, `AgentPlatformBackend` | | Review | Reviewed by a person, extracted by a model | ## Find it in your code ```sh npx harbyn scan ``` This change names no identifier the scanner can match line by line, so the scan tells you whether your repository uses Firebase, from its packages and API hosts. Nothing leaves your machine. ## Sources Where this event comes from: the page we read, when we read it, and the hash of that snapshot. - (changelog, fetched 2026-10-21 14:31 UTC, sha256 `d7865473e313c5d5488bc88b4041d0a86a290681edd2cc31f533d9d2ea9d7ef2`) ## Related changes ### More from Firebase - [Auth initialization handles invalidated users selectively](https://harbyn.com/changes/firebase/2026-10-21-auth-initialization-handles-invalidated-users-selectively.md) (Behavior change, announced Oct 21, 2026) - [Firebase CLI v15.34.1 updates command behavior](https://harbyn.com/changes/firebase/2026-10-22-firebase-cli-v15-34-1-updates-command-behavior.md) (Behavior change, announced Oct 22, 2026) - [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) ### 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)