@molecule/api-ai-google

Google Gemini AI provider for molecule.dev.

Auto-generated, AI-first package reference for the molecule.dev ecosystem. It is written to be read by coding agents as much as by people, and is generated from this package's source — edit src/index.ts JSDoc, not this file.

Quick Start

// npm install @molecule/api-ai-google --workspace=api
import { setProvider, requireProvider } from '@molecule/api-ai'
import { provider } from '@molecule/api-ai-google'

// Named registration — several AI providers can be bonded side by side
// (getProviderByName('google') targets this one); the FIRST one
// registered also answers requireProvider() (see @molecule/api-ai).
setProvider('google', provider) // reads GOOGLE_AI_API_KEY from the environment

let reply = ''
for await (const event of requireProvider().chat({
  messages: [{ role: 'user', content: 'Hello!' }],
})) {
  if (event.type === 'text') reply += event.content // or forward the chunk to the client (SSE)
}

Type

provider

Installation

npm install @molecule/api-ai-google @molecule/api-ai @molecule/api-bond @molecule/api-i18n @molecule/api-secrets

API

Interfaces

`GoogleConfig`

Configuration for the Google Gemini AI provider.

interface GoogleConfig {
  /** Called on each rate-limited/overloaded upstream response, before any retry sleep. */
  onRateLimit?: AiRateLimitCallback
  /** API key. Defaults to the `GOOGLE_AI_API_KEY` env var. */
  apiKey?: string
  /**
   * Base URL override (for proxies / gateways). Defaults to the
   * `GOOGLE_AI_BASE_URL` env var, then Google's public Generative Language
   * endpoint (`https://generativelanguage.googleapis.com/v1beta`).
   */
  baseUrl?: string
  /**
   * Default model id when not overridden per-request. Defaults to the
   * `GOOGLE_AI_MODEL` env var, then `gemini-3.8-flash`.
   */
  model?: string
}

`ProcessEnv`

Process env vars read by the Google Gemini AI bond.

interface ProcessEnv {
  /** Google AI (Gemini) API key. */
  GOOGLE_AI_API_KEY: string
  /** Base URL override (for credential brokers / gateways). */
  GOOGLE_AI_BASE_URL?: string
  /** Default model id override. */
  GOOGLE_AI_MODEL?: string
}

Functions

`createProvider(config)`

Creates a Google Gemini AI provider instance.

function createProvider(config?: GoogleConfig): AIProvider

config — Google-specific configuration (API key, base URL, model).

Returns: An AIProvider backed by the Google Generative Language REST API.

Constants

`provider`

The provider implementation.

const provider: AIProvider

`aiGoogleSecretDefinitions`

Secret definitions required by the Google AI bond.

const aiGoogleSecretDefinitions: SecretDefinition[]

Core Interface

Implements @molecule/api-ai interface.

Bond Wiring

Setup function to register this provider with the bond system:

import { bond } from '@molecule/api-bond'
import { provider } from '@molecule/api-ai-google'

export function setupAiGoogle(): void {
  bond('ai', 'google', provider)
}

Injection Notes

Requirements

Peer dependencies:

@molecule/api-ai ^1.0.1
@molecule/api-bond ^1.0.1
@molecule/api-i18n ^1.0.1
@molecule/api-secrets ^1.0.1

Environment Variables

GOOGLE_AI_API_KEY (required) — Google AI (Gemini) API key
- Setup: Create a Gemini API key in Google AI Studio.
- Get it here: https://aistudio.google.com/apikey
- Example: AIza...

Runtime Dependencies

@molecule/api-ai
@molecule/api-bond
@molecule/api-i18n
@molecule/api-secrets

Config: GOOGLE_AI_API_KEY (SERVER-side only) plus an optional default model id/base URL. Missing GOOGLE_AI_API_KEY fails fast (throws naming the exact env var on first use — the exported provider is a lazy proxy, so this fires on the first chat() call).

Error message disambiguation: a plain 400 that ISN'T a context-length error (bad param, malformed tool schema) gets its own non-retryable message distinct from the generic "AI service error. Please try again." used for retryable failures.

E2E Tests

Integration checklist — drive the real UI (live preview, no mocks), adapt each item to this app's actual chat/AI screens, and check every box off one by one. A box you can't check is an integration bug to fix — not a skip. The sandbox HAS an AI provider bonded, so the flow runs live end-to-end; AI output is NON-DETERMINISTIC, so assert on STRUCTURE/behavior, not exact text:

A message sent through the real chat UI comes back as a RELEVANT AI reply — not an echo of the prompt, a hardcoded stub, or an empty bubble. Ask something with a checkable answer (e.g. "What is 2 + 2?") and confirm the response actually contains it ("4"), proving a live model answered.
If the app streams, tokens render INCREMENTALLY — text grows word by word in the UI, not one final blob dumped after a long frozen spinner. (A streamed chat() yields text chunks then a final done; a single late blob means the reply was awaited whole and streaming is broken.)
Multi-turn CONTEXT is preserved: a follow-up that refers back to the previous turn (e.g. after "2 + 2", ask "now double that" -> understood as 8) works — proving the full messages history is sent, not just the last line.
A provider failure (bad/missing key, rate limit, timeout) surfaces as a graceful in-UI error message, NOT a crash, blank screen, a spinner that never resolves, or an unhandled 500. Force one and watch the UI recover.
The provider key + the provider call are SERVER-side only: the key never reaches the browser (check the network tab, the JS bundle, and page globals), and no route proxies arbitrary prompts to the model without auth
- a token cap — an open AI endpoint is an unbounded bill and abuse vector.

`@molecule/api-ai-google`

How it works

Reference