St. Nebula
158 lines
4.0 KiB
Markdown
158 lines
4.0 KiB
Markdown
# Genkit Examples
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This reference contains minimal, reproducible examples (MREs) for common Genkit patterns.
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> **Disclaimer**: These examples use **Google AI** models (`googleAI`, `gemini-*`) for demonstration. The patterns apply to **any provider**. To use a different provider:
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> 1. Search the docs for the correct plugin: `genkit docs:search "plugins"`.
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> 2. Install and configure the plugin.
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> 3. Swap the model reference in the code.
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## Basic Text Generation
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```ts
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import { genkit } from "genkit";
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import { googleAI } from "@genkit-ai/google-genai";
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const ai = genkit({
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plugins: [googleAI()],
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});
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const { text } = await ai.generate({
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model: googleAI.model('gemini-2.5-flash'),
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prompt: 'Tell me a story in a pirate accent',
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});
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```
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## Structured Output
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```ts
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import { z } from 'genkit';
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const JokeSchema = z.object({
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setup: z.string().describe('The setup of the joke'),
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punchline: z.string().describe('The punchline'),
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});
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const response = await ai.generate({
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model: googleAI.model('gemini-2.5-flash'),
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prompt: 'Tell me a joke about developers.',
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output: { schema: JokeSchema },
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});
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// response.output is strongly typed
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const joke = response.output;
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if (joke) {
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console.log(`${joke.setup} ... ${joke.punchline}`);
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}
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```
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## Streaming
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```ts
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const { stream, response } = ai.generateStream({
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model: googleAI.model('gemini-2.5-flash'),
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prompt: 'Tell a long story about a developer using Genkit.',
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});
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for await (const chunk of stream) {
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console.log(chunk.text);
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}
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// Await the final response
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const finalResponse = await response;
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console.log('Complete:', finalResponse.text);
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```
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## Advanced Configuration
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### Thinking Mode (Gemini 3 Only)
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Enable "thinking" process for complex reasoning tasks.
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```ts
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const response = await ai.generate({
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model: googleAI.model('gemini-3.1-pro-preview'),
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prompt: 'what is heavier, one kilo of steel or one kilo of feathers',
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config: {
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thinkingConfig: {
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thinkingLevel: 'HIGH', // or 'LOW'
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includeThoughts: true, // Returns thought process in response
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},
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},
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});
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```
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### Google Search Grounding
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Enable models to access current information via Google Search.
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```ts
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const response = await ai.generate({
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model: googleAI.model('gemini-2.5-flash'),
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prompt: 'What are the top tech news stories this week?',
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config: {
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googleSearchRetrieval: true,
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},
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});
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// Access grounding metadata (sources)
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const groundingMetadata = (response.custom as any)?.candidates?.[0]?.groundingMetadata;
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if (groundingMetadata) {
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console.log('Sources:', groundingMetadata.groundingChunks);
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}
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```
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## Multimodal Generation
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### Image Generation / Editing
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**Critical**: You MUST set `responseModalities: ['TEXT', 'IMAGE']` when using image generation models.
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```ts
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// Generate an image
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const { media } = await ai.generate({
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model: googleAI.model('gemini-2.5-flash-image'),
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config: { responseModalities: ['TEXT', 'IMAGE'] },
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prompt: "generate a picture of a unicorn wearing a space suit on the moon",
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});
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// media.url contains the data URI
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```
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```ts
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// Edit an image
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const { media } = await ai.generate({
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model: googleAI.model('gemini-2.5-flash-image'),
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config: { responseModalities: ['TEXT', 'IMAGE'] },
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prompt: [
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{ text: "change the person's outfit to a banana costume" },
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{ media: { url: "https://example.com/photo.jpg" } },
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],
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});
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```
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### Speech Generation (TTS)
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Generate audio from text.
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```ts
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import { writeFile } from 'node:fs/promises';
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const { media } = await ai.generate({
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model: googleAI.model('gemini-2.5-flash-preview-tts'),
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config: {
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responseModalities: ['AUDIO'],
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speechConfig: {
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voiceConfig: {
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prebuiltVoiceConfig: { voiceName: 'Algenib' }, // Options: 'Puck', 'Charon', 'Fenrir', etc.
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},
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},
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},
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prompt: 'Genkit is an amazing library',
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});
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// The response contains raw PCM data in media.url (base64 encoded).
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// CAUTION: This is NOT an MP3/WAV file. It requires conversion (e.g., PCM to WAV).
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// DO NOT GUESS. Run `genkit docs:search "speech audio"` to find the correct
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// conversion code for your provider.
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```
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