#Generating

You can generate responses using ADK with the Vercel AI SDK's generateText or streamText functions. ADK orchestrates the agent loop natively on Android while the provider bridges tool execution and streaming back to JavaScript. Import the default provider, call adk() to construct a language model, and pass it to the AI SDK — the default export targets on-device Gemini Nano.

#Requirements

• Physical Android device with AICore - Required for Gemini Nano; the device must be capable of running Gemini Nano. Please consult the ML Kit GenAI documentation. We provide runtime checks for this capability - please refer to Getting Started - On-device Gemini Nano.
• Polyfills - Streaming requires ReadableStream; see Polyfills
• Prepare Nano - Call prepareNano() or model.prepare() before first on-device use (see Getting Started - On-device Gemini Nano)

#Text Generation

import { adk } from '@react-native-ai/adk'
import { generateText } from 'ai'

await adk.prepareNano()

const { text } = await generateText({
  model: adk(),
  prompt: 'Explain quantum computing in simple terms',
})

#Cloud Gemini

Cloud models use ADK's LlmAgent with Google's Gemini API. This is useful when Gemini Nano is unavailable, you need a more capable model, or you want to develop on an emulator without AICore. Create a provider with modelType: 'gemini' and an API key:

import { createAdkProvider } from '@react-native-ai/adk'
import { generateText } from 'ai'

const adk = createAdkProvider({
  modelType: 'gemini',
  modelName: 'gemini-2.5-flash',
  apiKey: process.env.GOOGLE_API_KEY,
})

const { text } = await generateText({
  model: adk(),
  prompt: 'Explain quantum computing in simple terms',
})

Cloud models do not require a separate download or prepare step.

Do not embed API keys in production client apps. Prefer a backend proxy or secure runtime configuration.

#Streaming

Stream responses for real-time output:

import { adk } from '@react-native-ai/adk'
import { streamText } from 'ai'

await adk.prepareNano()

const { textStream } = await streamText({
  model: adk(),
  prompt: 'Write a short story about a robot learning to paint',
})

for await (const delta of textStream) {
  console.log(delta)
}

During streaming, the provider emits standard AI SDK stream parts: text-start, text-delta, text-end, and finish with usage metadata.

#Usage Metadata

ADK returns token usage in response events (promptTokenCount, candidatesTokenCount, totalTokenCount). The provider maps this into AI SDK usage on both generateText results and streaming finish events:

import { adk } from '@react-native-ai/adk'
import { generateText } from 'ai'

await adk.prepareNano()

const { usage } = await generateText({
  model: adk(),
  prompt: 'Count to five.',
})

console.log(usage.inputTokens.total) // promptTokenCount
console.log(usage.outputTokens.total) // candidatesTokenCount
console.log(usage.raw?.totalTokenCount)

#Tool Calling

Enable ADK agents to call JavaScript tools during generation. Works on both on-device Nano and cloud Gemini.

#Important ADK-Specific Behavior

Tools are orchestrated by ADK natively, which means:

• Pre-register executors: Pass tools to createAdkProvider via availableTools so ADK can invoke their execute handlers
• Provider-executed: Streamed tool calls are marked with providerExecuted: true
• Native agent loop: ADK runs the multi-turn tool loop; AI SDK maxSteps does not control ADK's internal iteration

#Setup

ADK needs tool executors registered both in the AI SDK and on the provider. Use createAdkProvider with availableTools, then pass tools to the AI SDK and call adk() as usual. Example:

import { createAdkProvider } from '@react-native-ai/adk'
import { generateText, tool } from 'ai'
import { z } from 'zod'

const getCurrentTime = tool({
  description: 'Get the current time for a city',
  inputSchema: z.object({
    city: z.string(),
  }),
  execute: async ({ city }) => ({
    city,
    time: new Date().toLocaleTimeString(),
  }),
})

const adk = createAdkProvider({
  availableTools: { getCurrentTime },
})

await adk.prepareNano()

const { text } = await generateText({
  model: adk(),
  tools: { getCurrentTime },
  prompt: 'What time is it in Warsaw?',
})

During streaming, the provider emits tool-input-start, tool-input-delta, tool-input-end, and tool-call stream parts when ADK surfaces function calls from the model.

Pass tools through the AI SDK tools option as usual; the provider bridges execution to JavaScript while ADK orchestrates the agent loop natively.

#Updating Tools at Runtime

Register tools when creating the provider so ADK can execute them from JavaScript:

import { adk } from '@react-native-ai/adk'

const model = adk()

// Add or replace tools on an existing model instance
model.updateTools({
  getCurrentTime,
})

To register executors at provider creation time:

import { createAdkProvider } from '@react-native-ai/adk'
import { tool } from 'ai'
import { z } from 'zod'

const getCurrentTime = tool({
  description: 'Get the current time for a city',
  inputSchema: z.object({ city: z.string() }),
  execute: async ({ city }) => ({
    city,
    time: new Date().toLocaleTimeString(),
  }),
})

const adk = createAdkProvider({
  availableTools: { getCurrentTime },
})

const model = adk()

model.updateTools({
  getCurrentTime,
})

#Multimodal Input

Pass file parts in user messages using the standard AI SDK prompt format:

import { adk } from '@react-native-ai/adk'
import { generateText } from 'ai'

await adk.prepareNano()

const { text } = await generateText({
  model: adk(),
  messages: [
    {
      role: 'user',
      content: [
        { type: 'text', text: 'What is in this image?' },
        {
          type: 'file',
          mediaType: 'image/jpeg',
          data: base64Image,
        },
      ],
    },
  ],
})

Supported file data formats:

• Base64 strings - Raw base64 or data:image/jpeg;base64,... data URLs
• Uint8Array - Binary image data

Note: File URLs (file:// or HTTP) are not supported yet. Pass base64 or Uint8Array data directly.

#Structured Output

Generate JSON responses using AI SDK JSON mode:

import { adk } from '@react-native-ai/adk'
import { generateText } from 'ai'

await adk.prepareNano()

const { text } = await generateText({
  model: adk(),
  prompt: 'Return a JSON object with name and age fields.',
  responseFormat: { type: 'json' },
})

Note: JSON schema constraints (responseFormat.schema) are not supported yet. Use JSON mode without a schema, or parse and validate the response in your app.

Streaming structured JSON is not supported by ADK yet.

#Available Options

Configure model behavior with generation options:

Example:

import { adk } from '@react-native-ai/adk'
import { generateText } from 'ai'

await adk.prepareNano()

const { text } = await generateText({
  model: adk(),
  prompt: 'Write a creative story',
  temperature: 0.8,
  maxOutputTokens: 500,
  topP: 0.9,
  topK: 40,
})

#Limitations

The following features are not yet supported:

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