The Google Gemini adapter provides access to Google's Gemini models, including text generation, image generation with both Imagen and Gemini native image models (NanoBanana), and experimental text-to-speech.
For a full working example with image generation, see the media generation example app.
npm install @tanstack/ai-geminiimport { chat } from "@tanstack/ai";
import { geminiText } from "@tanstack/ai-gemini";
const stream = chat({
adapter: geminiText("gemini-3.1-pro-preview"),
messages: [{ role: "user", content: "Hello!" }],
});import { chat } from "@tanstack/ai";
import { createGeminiChat } from "@tanstack/ai-gemini";
const adapter = createGeminiChat("gemini-3.1-pro-preview", process.env.GEMINI_API_KEY!, {
// ... your config options
});
const stream = chat({
adapter,
messages: [{ role: "user", content: "Hello!" }],
});import { createGeminiChat, type GeminiTextConfig } from "@tanstack/ai-gemini";
const config: Omit<GeminiTextConfig, "apiKey"> = {
httpOptions: {
baseUrl: "https://generativelanguage.googleapis.com/v1beta", // Optional
},
};
const adapter = createGeminiChat("gemini-3.1-pro-preview", process.env.GEMINI_API_KEY!, config);import { chat, toServerSentEventsResponse } from "@tanstack/ai";
import { geminiText } from "@tanstack/ai-gemini";
export async function POST(request: Request) {
const { messages } = await request.json();
const stream = chat({
adapter: geminiText("gemini-3.1-pro-preview"),
messages,
});
return toServerSentEventsResponse(stream);
}import { chat, toServerSentEventsResponse, toolDefinition } from "@tanstack/ai";
import { geminiText } from "@tanstack/ai-gemini";
import { z } from "zod";
const getCalendarEventsDef = toolDefinition({
name: "get_calendar_events",
description: "Get calendar events for a date",
inputSchema: z.object({
date: z.string(),
}),
});
const getCalendarEvents = getCalendarEventsDef.server(async ({ date }) => {
// Fetch calendar events
return { events: [] };
});
export async function POST(request: Request) {
const { messages } = await request.json();
const stream = chat({
adapter: geminiText("gemini-3.1-pro-preview"),
messages,
tools: [getCalendarEvents],
});
return toServerSentEventsResponse(stream);
}Gemini's Interactions API (currently in Beta) offers server-side conversation state — the Gemini equivalent of OpenAI's Responses API. Instead of replaying the full message history on every turn, you pass a previous_interaction_id and the server retains the transcript. This also improves cache hit rates for repeated prefixes.
The geminiTextInteractions adapter routes through client.interactions.create and surfaces the server-assigned interaction id via an AG-UI CUSTOM event (name: 'gemini.interactionId') emitted just before RUN_FINISHED, so you can chain turns.
⚠️ Experimental. Google marks the Interactions API as Beta and explicitly flags possible breaking changes until it reaches general availability. The adapter is exported from the @tanstack/ai-gemini/experimental subpath so the experimental status is load-bearing in your editor and bundle. Text output, function tools, and the built-in tools google_search, code_execution, url_context, file_search, and computer_use are supported. google_search_retrieval, google_maps, and mcp_server still throw on this adapter — use geminiText() for those or wait for follow-up work.
import { chat } from "@tanstack/ai";
import { geminiTextInteractions } from "@tanstack/ai-gemini/experimental";
// Turn 1: introduce yourself, capture the interaction id.
let interactionId: string | undefined;
for await (const chunk of chat({
adapter: geminiTextInteractions("gemini-3.5-flash"),
messages: [{ role: "user", content: "Hi, my name is Amir." }],
})) {
if (
chunk.type === "CUSTOM" &&
chunk.name === "gemini.interactionId" &&
chunk.value &&
typeof chunk.value === "object" &&
"interactionId" in chunk.value
) {
interactionId = String(chunk.value.interactionId);
}
}
// Turn 2: only send the new turn's content — the server has the history.
for await (const chunk of chat({
adapter: geminiTextInteractions("gemini-3.5-flash"),
messages: [{ role: "user", content: "What is my name?" }],
modelOptions: {
previous_interaction_id: interactionId,
},
})) {
// ...stream "Your name is Amir." back to the client.
}The Interactions API is stateful and does not accept multi-turn history without a previous_interaction_id — if a chat client sends [user, assistant, user] to a fresh interaction the adapter throws cannot send prior conversation history on a fresh interaction. To make useChat work, persist the server-assigned id and send it back on the next turn:
Server route (e.g. TanStack Start handler):
import {
chat,
chatParamsFromRequestBody,
toServerSentEventsResponse,
} from "@tanstack/ai";
import { geminiTextInteractions } from "@tanstack/ai-gemini/experimental";
export async function POST({ request }: { request: Request }) {
const params = await chatParamsFromRequestBody(await request.json());
// The client sends body.previousInteractionId; AG-UI maps `body` into
// `forwardedProps` on the wire.
const previousInteractionId =
typeof params.forwardedProps.previousInteractionId === "string"
? params.forwardedProps.previousInteractionId
: undefined;
const stream = chat({
adapter: geminiTextInteractions("gemini-3.5-flash"),
messages: params.messages,
modelOptions: {
previous_interaction_id: previousInteractionId,
store: true, // required for chaining on the next turn
},
});
return toServerSentEventsResponse(stream);
}React client:
import { useEffect, useMemo, useState } from "react";
import { fetchServerSentEvents, useChat } from "@tanstack/ai-react";
function GeminiChat() {
const [interactionId, setInteractionId] = useState<string | undefined>();
const body = useMemo(
() => (interactionId ? { previousInteractionId: interactionId } : {}),
[interactionId],
);
const { messages, setMessages, sendMessage } = useChat({
connection: fetchServerSentEvents("/api/chat"),
body,
onCustomEvent: (eventType, data) => {
if (
eventType === "gemini.interactionId" &&
typeof data === "object" &&
data !== null &&
"interactionId" in data
) {
setInteractionId(String(data.interactionId));
}
},
});
// Switching provider/model resets the server-side chain — drop the id
// AND the local message history together, otherwise the next turn
// ships multi-turn messages with no previous_interaction_id and the
// adapter errors out.
const [provider, setProvider] = useState("gemini-interactions");
useEffect(() => {
setInteractionId(undefined);
setMessages([]);
}, [provider]);
// ...render messages, call sendMessage(input)
}The full working example is in examples/ts-react-chat — see src/routes/index.tsx for the client and src/routes/api.tanchat.ts for the route.
| Concern | geminiText | geminiTextInteractions |
|---|---|---|
| Underlying endpoint | models:generateContent | interactions:create |
| Conversation state | Stateless — send full history each turn | Stateful — server retains transcript via previous_interaction_id |
| Provider options shape | camelCase (stopSequences, responseModalities, safetySettings) | snake_case (generation_config, response_modalities, previous_interaction_id) |
| Built-in tools | google_search, code_execution, url_context, file_search, google_maps, google_search_retrieval, computer_use | google_search, code_execution, url_context, file_search, computer_use (only the first four stream CUSTOM event activity; computer_use is accepted in the request but does not currently emit per-delta events) |
| Stability | GA | Experimental (Google Beta) |
The adapter exposes Interactions-specific options on modelOptions:
import { chat } from "@tanstack/ai";
import { geminiTextInteractions } from "@tanstack/ai-gemini/experimental";
const stream = chat({
adapter: geminiTextInteractions("gemini-3.5-flash"),
messages: [{ role: "user", content: "Hello!" }],
modelOptions: {
// Stateful chaining — passed only on turn 2+.
previous_interaction_id: "int_abc123",
// Persist the interaction server-side (default true). Must be true for
// previous_interaction_id to work on the *next* turn.
store: true,
// Per-request system instruction (interaction-scoped — re-specify each turn).
system_instruction: "You are a helpful assistant.",
// snake_case generation config distinct from geminiText's camelCase one.
generation_config: {
thinking_level: "low",
thinking_summaries: "auto",
stop_sequences: ["<done>"],
},
response_modalities: ["text"],
},
});The server's interaction id arrives as an AG-UI CUSTOM event emitted just before RUN_FINISHED:
for await (const chunk of stream) {
if (
chunk.type === "CUSTOM" &&
chunk.name === "gemini.interactionId" &&
typeof chunk.value === "object" &&
chunk.value !== null &&
"interactionId" in chunk.value
) {
const id = String(chunk.value.interactionId);
// Persist `id` wherever you store per-user conversation pointers —
// pass it back on the next turn as `previous_interaction_id`.
}
}Gemini supports various model-specific options. Sampling parameters live here too — temperature, topP, and maxOutputTokens — rather than as root-level props on chat():
import { chat } from "@tanstack/ai";
import { geminiText } from "@tanstack/ai-gemini";
const stream = chat({
adapter: geminiText("gemini-3.1-pro-preview"),
messages: [{ role: "user", content: "Hello!" }],
modelOptions: {
maxOutputTokens: 2048,
temperature: 0.7,
topP: 0.9,
topK: 40,
stopSequences: ["END"],
},
});If you previously passed temperature / topP / maxTokens at the root of chat(), see Moving Sampling Options into modelOptions.
Enable thinking for models that support it:
modelOptions: {
thinking: {
includeThoughts: true,
},
}Configure structured output format:
modelOptions: {
responseMimeType: "application/json",
}Summarize long text content:
import { summarize } from "@tanstack/ai";
import { geminiSummarize } from "@tanstack/ai-gemini";
const result = await summarize({
adapter: geminiSummarize("gemini-3.1-pro-preview"),
text: "Your long text to summarize...",
maxLength: 100,
style: "concise", // "concise" | "bullet-points" | "paragraph"
});
console.log(result.summary);Generate embedding vectors with gemini-embedding-001:
import { embed } from "@tanstack/ai";
import { geminiEmbedding } from "@tanstack/ai-gemini";
const result = await embed({
adapter: geminiEmbedding("gemini-embedding-001"),
input: "a red guitar",
dimensions: 1536,
modelOptions: {
taskType: "RETRIEVAL_DOCUMENT",
},
});
console.log(result.embeddings[0]?.vector);The Gemini API's embedding endpoint does not report token usage, so result.usage is absent. The Vertex-only multimodal embedding model (multimodalembedding@001) is not supported by this adapter.
See the Embeddings guide for the full API.
The Gemini adapter supports two types of image generation:
The adapter routes to generateContent when the model is in GEMINI_NATIVE_IMAGE_MODELS. Imagen models, and any id this package does not know, use generateImages. Import the list or isGeminiNativeImageModel from @tanstack/ai-gemini.
From the media generation example app:
import { generateImage } from "@tanstack/ai";
import { geminiImage } from "@tanstack/ai-gemini";
const result = await generateImage({
adapter: geminiImage("gemini-3.1-flash-image"),
prompt: "A futuristic cityscape at sunset",
numberOfImages: 1,
size: "16:9_4K",
});
console.log(result.images);import { generateImage } from "@tanstack/ai";
import { geminiImage } from "@tanstack/ai-gemini";
const result = await generateImage({
adapter: geminiImage("imagen-4.0-generate-001"),
prompt: "A futuristic cityscape at sunset",
numberOfImages: 1,
});
console.log(result.images);Gemini native image models use a template literal size format combining aspect ratio and resolution tier:
// Format: "aspectRatio_resolution"
size: "16:9_4K"
size: "1:1_2K"
size: "9:16_1K"The accepted set differs per model, and each model's size is narrowed to its own set at compile time:
| Model | Aspect ratios | Resolutions |
|---|---|---|
| gemini-3.1-flash-image | 1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9, 1:4, 4:1, 1:8, 8:1 | 512, 1K, 2K, 4K |
| gemini-3.1-flash-lite-image | same 14 as above (see note) | 1K only |
| gemini-3-pro-image | 1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9 | 1K, 2K, 4K |
| gemini-2.5-flash-image | same 10 as above | none — pass the bare ratio, e.g. size: "16:9" |
The K is case-sensitive (1k is rejected by the API), the smallest tier's token is 512 (not 512px or 0.5K), and 9:21 is Vertex/Cloud-only so it is not accepted here. Google documents no image_size for gemini-2.5-flash-image, so that model takes a bare aspect ratio and the adapter sends no imageSize.
Note on gemini-3.1-flash-lite-image. The four extreme banner ratios (1:4, 4:1, 1:8, 8:1) are partially inferred for this model. Unlike the other three, Flash Lite has no per-model ratio table in Google's Gemini API guide; the 14-value set comes from the Cloud model page's explicit enumeration plus the guide's bare "a discrete set of 14 aspect ratios" assertion. The only Gemini-API enumeration for it is a 10-item bullet headed "New aspect ratios", which we read as a what's-new list rather than an exhaustive one. If the API rejects those four in practice, prefer the 10 standard ratios on this model.
Imagen models use WIDTHxHEIGHT format, which maps to aspect ratios internally:
| Size | Aspect Ratio |
|---|---|
| 1024x1024 | 1:1 |
| 1920x1080 | 16:9 |
| 1080x1920 | 9:16 |
Alternatively, you can specify the aspect ratio directly in Model Options:
import { generateImage } from "@tanstack/ai";
import { geminiImage } from "@tanstack/ai-gemini";
const result = await generateImage({
adapter: geminiImage("imagen-4.0-generate-001"),
prompt: "A landscape photo",
modelOptions: {
aspectRatio: "16:9",
},
});modelOptions is typed per model family, because the two families hit different APIs.
Imagen models (generateImages) take GenerateImagesConfig fields:
import { generateImage } from "@tanstack/ai";
import { geminiImage } from "@tanstack/ai-gemini";
const result = await generateImage({
adapter: geminiImage("imagen-4.0-generate-001"),
prompt: "...",
modelOptions: {
aspectRatio: "16:9", // "1:1" | "3:4" | "4:3" | "9:16" | "16:9"
personGeneration: "DONT_ALLOW", // Control person generation
safetyFilterLevel: "BLOCK_SOME", // Safety filtering
},
});Gemini native models (generateContent) take seed, safetySettings, thinkingConfig, imageConfig, and systemInstruction. imageConfig accepts only aspectRatio and imageSize on the Gemini Developer API.
import { generateImage } from "@tanstack/ai";
import { geminiImage } from "@tanstack/ai-gemini";
const result = await generateImage({
adapter: geminiImage("gemini-3.1-flash-image"),
prompt: "...",
size: "16:9_4K",
modelOptions: {
thinkingConfig: { thinkingBudget: 512 },
// Merged over the imageConfig derived from `size`, per field.
imageConfig: { imageSize: "2K" },
},
});See Image Generation for the full native option list.
Note: Gemini TTS is experimental and may require the Live API for full functionality.
Generate speech from text:
import { generateSpeech } from "@tanstack/ai";
import { geminiSpeech } from "@tanstack/ai-gemini";
const result = await generateSpeech({
adapter: geminiSpeech("gemini-3.1-flash-tts-preview"),
text: "Hello from Gemini TTS!",
});
console.log(result.audio); // Base64 encoded audioSet your API key in environment variables:
GEMINI_API_KEY=your-api-key-here
# or
GOOGLE_API_KEY=your-api-key-hereThese models use the generateContent API and support per-model resolution tiers.
| Model | Description |
|---|---|
| gemini-3.1-flash-image | Nano Banana 2 — latest and fastest Gemini native image generation (512/1K/2K/4K) |
| gemini-3.1-flash-lite-image | Nano Banana 2 Lite — ultra-low-latency, low-cost image generation (1K only) |
| gemini-3-pro-image | Nano Banana Pro — higher quality Gemini native image generation (1K/2K/4K) |
| gemini-2.5-flash-image | Nano Banana — legacy; shuts down 2026-10-02. Takes a bare aspect ratio |
The gemini-3.1-flash-image-preview and gemini-3-pro-image-preview ids were shut down on 2026-06-25. They remain in the type union as deprecated aliases so existing code compiles, but calls to them fail — use the GA ids above.
These models use the dedicated generateImages API.
| Model | Description |
|---|---|
| imagen-4.0-ultra-generate-001 | Best quality Imagen image generation |
| imagen-4.0-generate-001 | High quality Imagen image generation |
| imagen-4.0-fast-generate-001 | Fast Imagen image generation |
Every factory pair follows the same shape: the short factory (geminiText, geminiImage, …) reads GEMINI_API_KEY (or GOOGLE_API_KEY) from the environment, while the create* variant takes an explicit API key. Both take model as the first argument.
Creates a Gemini text/chat adapter.
Parameters:
Creates a Gemini Interactions API text adapter. Backs the stateful conversation pattern via previous_interaction_id. Exported from @tanstack/ai-gemini/experimental.
Parameters:
Creates a Gemini summarization adapter.
Creates a Gemini image adapter. Models in GEMINI_NATIVE_IMAGE_MODELS use generateContent. Imagen models, and any unknown id, use generateImages.
Creates a Gemini text-to-speech adapter. Experimental.
Creates a Gemini Lyria music generation adapter. Experimental.
Google Gemini exposes several native tools beyond user-defined function calls. Import them from @tanstack/ai-gemini/tools and pass them into chat({ tools: [...] }).
For the full concept, a comparison matrix, and type-gating details, see Provider Tools.
Enables Gemini to execute Python code in a sandboxed environment and return results inline. Takes no arguments — include it in the tools array to activate code execution.
import { chat } from "@tanstack/ai";
import { geminiText } from "@tanstack/ai-gemini";
import { codeExecutionTool } from "@tanstack/ai-gemini/tools";
const stream = chat({
adapter: geminiText("gemini-3.1-pro-preview"),
messages: [{ role: "user", content: "Calculate the first 10 Fibonacci numbers" }],
tools: [codeExecutionTool()],
});Supported models: Gemini 1.5 Pro, Gemini 2.x, Gemini 2.5 and above. See Provider Tools.
Searches files that have been uploaded to the Gemini File API. Pass a FileSearch config object with the corpus and file IDs to scope the search.
import { chat } from "@tanstack/ai";
import { geminiText } from "@tanstack/ai-gemini";
import { fileSearchTool } from "@tanstack/ai-gemini/tools";
const stream = chat({
adapter: geminiText("gemini-3.1-pro-preview"),
messages: [{ role: "user", content: "Find the quarterly revenue figures" }],
tools: [
fileSearchTool({
fileSearchStoreNames: ["fileSearchStores/my-file-search-store-123"],
}),
],
});Supported models: Gemini 2.x and above. See Provider Tools.
Enables Gemini to query Google Search and incorporate grounded search results into its response. Pass an optional GoogleSearch config or call with no arguments to use defaults.
import { chat } from "@tanstack/ai";
import { geminiText } from "@tanstack/ai-gemini";
import { googleSearchTool } from "@tanstack/ai-gemini/tools";
const stream = chat({
adapter: geminiText("gemini-3.1-pro-preview"),
messages: [{ role: "user", content: "What's the weather in Tokyo right now?" }],
tools: [googleSearchTool()],
});Supported models: Gemini 1.5 Pro, Gemini 2.x, Gemini 2.5. See Provider Tools.
A retrieval-augmented variant of Google Search that returns ranked passages from the web with configurable dynamic retrieval mode. Pass an optional GoogleSearchRetrieval config.
import { chat } from "@tanstack/ai";
import { geminiText } from "@tanstack/ai-gemini";
import { googleSearchRetrievalTool } from "@tanstack/ai-gemini/tools";
const stream = chat({
adapter: geminiText("gemini-3.1-pro-preview"),
messages: [{ role: "user", content: "Explain the latest JavaScript proposals" }],
tools: [
googleSearchRetrievalTool({
dynamicRetrievalConfig: { mode: "MODE_DYNAMIC", dynamicThreshold: 0.7 },
}),
],
});Supported models: Gemini 1.5 Pro and above. See Provider Tools.
Connects Gemini to the Google Maps API for location-aware queries such as directions, place search, and geocoding. Pass an optional GoogleMaps config or call with no arguments.
import { chat } from "@tanstack/ai";
import { geminiText } from "@tanstack/ai-gemini";
import { googleMapsTool } from "@tanstack/ai-gemini/tools";
const stream = chat({
adapter: geminiText("gemini-2.5-pro"),
messages: [{ role: "user", content: "Find coffee shops near Union Square, SF" }],
tools: [googleMapsTool()],
});Supported models: Gemini 2.5 and above. See Provider Tools.
Fetches and includes the content of URLs mentioned in the conversation so Gemini can reason over live web pages. Takes no arguments.
import { chat } from "@tanstack/ai";
import { geminiText } from "@tanstack/ai-gemini";
import { urlContextTool } from "@tanstack/ai-gemini/tools";
const stream = chat({
adapter: geminiText("gemini-3.1-pro-preview"),
messages: [{ role: "user", content: "Summarise https://example.com/article" }],
tools: [urlContextTool()],
});Supported models: Gemini 2.x and above. See Provider Tools.
Allows Gemini to observe a virtual desktop via screenshots and interact with it using predefined computer-use functions. Provide the environment and optionally restrict callable functions via excludedPredefinedFunctions.
import { chat } from "@tanstack/ai";
import { geminiText } from "@tanstack/ai-gemini";
import { computerUseTool } from "@tanstack/ai-gemini/tools";
const stream = chat({
adapter: geminiText("gemini-3.1-pro-preview"),
messages: [{ role: "user", content: "Navigate to example.com in the browser" }],
tools: [
computerUseTool({
environment: "browser",
}),
],
});Supported models: Gemini 2.5 and above. See Provider Tools.