Firebase AI Logic Basics Agent Skill

Firebase AI Logic Basics

Overview

Firebase AI Logic is a product of Firebase that allows developers to add gen AI

to their mobile and web apps using client-side SDKs. You can call Gemini models

directly from your app without managing a dedicated backend. Firebase AI Logic,

which was previously known as "Vertex AI for Firebase", represents the evolution

of Google's AI integration platform for mobile and web developers.

It supports the two Gemini API providers:

• Gemini Developer API: It has a free tier ideal for prototyping, and

pay-as-you-go for production

• Agent Platform Gemini API (formerly branded Vertex AI): Ideal for scale

with enterprise-grade production readiness, requires Blaze plan

Use the Gemini Developer API as a default, and only Agent Platform Gemini API

(formerly branded Vertex AI) if the application requires it.

Setup & Initialization

Prerequisites

• Before starting, ensure you have Node.js 16+ and npm installed. Install

them if they aren’t already available.

• Identify the platform the user is interested in building on prior to

starting: Android, iOS, Flutter or Web.

• If their platform is unsupported, Direct the user to Firebase Docs to learn

how to set up AI Logic for their application (share this link with the user

https://firebase.google.com/docs/ai-logic/get-started)

Installation

The library is part of the standard Firebase Web SDK.

npm install -g firebase@latest

If you're in a firebase directory (with a firebase.json) the currently selected

project will be marked with "current" using this command:

npx -y firebase-tools@latest projects:list

Ensure there's at least one app associated with the current project

npx -y firebase-tools@latest apps:list

Initialize AI logic SDK with the init command

npx -y firebase-tools@latest init ailogic

This will automatically enable the Gemini Developer API in the Firebase console.

More info in

Firebase AI Logic Getting Started

Core Capabilities

> [!WARNING] CRITICAL: Use current model names: Always check the

> Firebase AI Logic Models documentation

> for the currently supported model names. Do NOT use gemini-2.0-pro or

> gemini-2.0-flash or other older models that are shutdown.

Text-Only Generation

Multimodal (Text + Images/Audio/Video/PDF input)

Firebase AI Logic allows Gemini models to analyze image files directly from your

app. This enables features like creating captions, answering questions about

images, detecting objects, and categorizing images. Beyond images, Gemini can

analyze other media types like audio, video, and PDFs by passing them as inline

data with their MIME type. For files larger than 20 megabytes (which can cause

HTTP 413 errors as inline data), store them in Cloud Storage for Firebase and

pass their URLs to the Gemini Developer API.

Chat Session (Multi-turn)

Maintain history automatically using startChat.

Streaming Responses

To improve the user experience by showing partial results as they arrive (like a

typing effect), use generateContentStream instead of generateContent for

faster display of results.

Generate Images with Nano Banana

> [!WARNING] Use current Image model names: Always check the

> Firebase AI Logic Models documentation

> for the currently supported image generation (Nano Banana) model names.

• Requires an upgraded Blaze pay-as-you-go billing plan.

Search Grounding with the built in googleSearch tool

Supported Platforms and Frameworks

Supported Platforms and Frameworks include Kotlin and Java for Android, Swift

for iOS, JavaScript for web apps, Dart for Flutter, and C Sharp for Unity.

Advanced Features

Structured Output (JSON)

Enforce a specific JSON schema for the response.

On-Device AI (Hybrid)

Hybrid on-device inference for web apps, where the Firebase Javascript SDK

automatically checks for Gemini Nano's availability (after installation) and

switches between on-device or cloud-hosted prompt execution. This requires

specific steps to enable model usage in the Chrome browser, more info in the

hybrid-on-device-inference documentation.

Security & Production

App Check

> [!WARNING] Critical Safety Requirement: In order to use AI Logic safely,

> you MUST set up App Check on your app. This prevents unauthorized clients from

> using your API quota and accessing your backend resources.

See

App Check with reCAPTCHA Enterprise

for setup instructions.

App Check Debug Tokens for Local Development & CI/CD

Because App Check attestation providers (like Play Integrity or DeviceCheck)

reject emulators, simulators, or CI environments, you must use **App Check Debug

Tokens** during development and testing to bypass standard attestation.

Local Development (Auto-Generated)

• Configure your code's App Check provider to use the debug factory:
• Web: Set self.FIREBASE_APPCHECK_DEBUG_TOKEN = true; before

initializing App Check.

• Android: Install DebugAppCheckProviderFactory.getInstance().
• iOS: Set provider factory to AppCheckDebugProviderFactory().
• Run your app in the emulator/localhost.
• Look at your runtime debugger console / Logcat logs for the generated UUID:
• *Example:* `AppCheck debug token:

"123a4567-b89c-12d3-e456-789012345678"`

• Register this token in the Firebase Console under **Security > App Check >

Apps > Manage debug tokens**.

CI/CD Pipelines (Pre-Provisioned)

• Generate and register a new debug token in the Firebase Console under

Security > App Check > Apps > Manage debug tokens.

• Add this token string as an encrypted secret in your CI system (e.g.

APP_CHECK_DEBUG_TOKEN).

• Configure your build to pass this secret as an environment variable to the

SDK during test execution (e.g. `self.FIREBASE_APPCHECK_DEBUG_TOKEN =

process.env.APP_CHECK_DEBUG_TOKEN`).

Remote Config

Consider that you do not need to hardcode model names (e.g., a specific model

version string). Use Firebase Remote Config to update model versions dynamically

without deploying new client code. See

Changing model names remotely

> [!WARNING] CRITICAL: Backend Provisioning Required For all platforms

> (Flutter, Android, iOS, Web), you MUST run npx firebase-tools init ailogic

> to provision the service. flutterfire configure ONLY handles client

> configuration and does NOT enable the AI service, leading to

> PERMISSION_DENIED errors.

Initialization Code References

| Language, | Gemini API | Context URL |

: Framework, : provider : :

: Platform : : :

| :---------- | :--------- | :---------------------------------------------- |

| Web Modular | Gemini | firebase://docs/ai-logic/get-started |

: API : Developer : :

: : API : :

: : (Developer : :

: : API) : :

| iOS (Swift) | Gemini | ios_setup.md |

: : Developer : :

: : API : :

| Flutter | Gemini | flutter_setup.md |

: (Dart) : Developer : :

: : API : :

> [!WARNING] CRITICAL: Use current model names: Always check the

> Firebase AI Logic Models documentation

> for the currently supported model names. Do NOT use gemini-2.0-pro or

> gemini-2.0-flash or other older models that are shutdown.

References

Web SDK code examples and usage patterns

iOS SDK code examples and usage patterns

Flutter SDK code examples and usage patterns

Android (Kotlin) SDK usage patterns