@ziro-agent/google

Google Gemini provider for the ZiroAgent SDK. Targets the Generative Language API over an API key, or Vertex AI via custom OAuth headers.

pnpm add @ziro-agent/google

Quick start

import { generateText } from '@ziro-agent/core';
import { google } from '@ziro-agent/google';

const result = await generateText({
  model: google('gemini-2.5-flash'),
  prompt: 'Explain quantum entanglement in two sentences.',
});

console.log(result.text);

API key resolution order:

1. createGoogle({ apiKey })
2. process.env.GOOGLE_GENERATIVE_AI_API_KEY
3. process.env.GEMINI_API_KEY

Streaming

import { streamText } from '@ziro-agent/core';
import { google } from '@ziro-agent/google';

const stream = await streamText({
  model: google('gemini-2.5-flash'),
  prompt: 'Stream a haiku about TypeScript',
});

for await (const delta of stream.toTextIterable()) process.stdout.write(delta);

The adapter targets :streamGenerateContent?alt=sse. Each SSE chunk is a JSON-encoded GenerateContentResponse and its parts are surfaced as either text-delta or tool-call events.

Tool calling

const result = await generateText({
  model: google('gemini-2.5-flash'),
  prompt: 'What time is it in Hanoi?',
  tools: [
    {
      name: 'getTime',
      description: 'Returns the current time in a city',
      parameters: {
        type: 'object',
        properties: { city: { type: 'string' } },
        required: ['city'],
      },
    },
  ],
});

Note that Gemini's API does not return ids for function calls. The adapter synthesizes a stable gemini_<name>_<index> id so downstream tool-result correlation still works. Treat them as opaque.

Vertex AI / OAuth

Pass an Authorization header — the adapter detects this and skips the ?key=... query parameter:

import { createGoogle } from '@ziro-agent/google';

const vertex = createGoogle({
  baseURL: 'https://us-central1-aiplatform.googleapis.com/v1/projects/<proj>/locations/us-central1/publishers/google',
  headers: { Authorization: `Bearer ${oauthToken}` },
});

Model ids

Verified against https://ai.google.dev/pricing on 2026-04-22:

| Id | Tier | Status | | --------------------------- | ------- | ---------- | | gemini-2.0-flash | Mid | verified | | gemini-2.0-flash-lite | Small | verified | | gemini-2.5-pro | Flagship| unverified | | gemini-2.5-flash | Mid | unverified | | gemini-2.5-flash-lite | Small | unverified |

The 2.5-series rows are marked unverified: true per RFC 0004's trust-recovery convention — Budget Guard's pre-flight USD bound returns pricingAvailable: false until they can be cross-referenced against the live pricing page. This avoids silently shipping a speculative rate.