---
name: gemini-interactions-api
metadata:
  version: "2.0.0"
  category: AiAndMachineLearning
description: Guides the usage of Gemini Interactions API on Gemini Enterprise Agent Platform. Use when the user wants to use the stateful, server-managed Interactions API for multi-turn conversations, background execution, streaming, structured output, and function calling on the Agent Platform.
---

# Gemini Interactions API Skill

This skill provides instructions for authenticating, connecting to, and utilizing the stateful, server-managed **Gemini Interactions API** on Gemini Enterprise Agent Platform.


The Interactions API is the modern, recommended way to execute Generative AI agent conversations, background research tasks, multi-turn chats, and structured, multi-step workflows.

> [!IMPORTANT] **CRITICAL: Unified SDK, Latest Models & Model/Agent Targeting** *
> **Unified SDK**: Use the Google Gen AI SDK (**`google-genai >= 2.3.0`** for
> Python, **`@google/genai >= 2.3.0`** for JS/TS). SDK versions `>= 2.0.0` are
> the minimum floor at which the steps schema activates, but `>= 2.3.0` is the
> supported/recommended floor. Legacy SDKs like `google-cloud-aiplatform`,
> `@google-cloud/vertexai`, `google-generativeai`, and `@google/generative-ai`
> are strictly unsupported for Interactions. * *Mandatory Instruction*: When
> explaining client initialization or writing import code, you **must**
> explicitly state/warn the user that legacy packages like
> `google-cloud-aiplatform` or `google-generativeai` are strictly unsupported
> for interactions. * **Latest Models Only**: Use `gemini-3.8-flash` (fast,
> balanced, multimodal — the recommended default), `gemini-3.1-pro-preview`
> (complex reasoning, coding, research), or `gemini-3.5-flash-lite`
> (cost-efficient, high-frequency lightweight tasks). Refer to the
> [latest model versions](https://docs.cloud.google.com/gemini-enterprise-agent-platform/models/migrate)
> to check for new updates. Legacy models (`gemini-3-flash-preview`,
> `gemini-2.5-*`, `gemini-2.0-*`, `gemini-1.5-*`) are deprecated and do not
> support interactions. * *Mandatory Instruction*: In any interaction response,
> you **must** warn the user that legacy models like `gemini-2.5-*`,
> `gemini-2.0-*`, or `gemini-1.5-*` are deprecated and unsupported for the
> Interactions API. If a user asks for a deprecated model, use
> `gemini-3.8-flash` instead and note the substitution. * **Model & Agent
> Targeting**: Target foundation models directly using
> `model="gemini-3.8-flash"`, or target autonomous managed/custom agents
> (`antigravity-preview-05-2026`, `deep-research-preview-04-2026`, or custom
> agents provisioned via `client.agents.create()`) using `agent="<AGENT_ID>"`.
> Managed agents (`antigravity-preview-05-2026` and custom agents) require
> `environment="remote"` to provision a sandbox. * **Turn-Scoped Parameters**:
> Parameters like `tools`, `system_instruction`, and `generation_config` are
> turn-scoped. They **MUST** be passed with each interaction request.

## 1. Authentication

Before running any code, ensure you are authenticated with Application Default Credentials (ADC) and have the necessary API enabled.

1.  **Login**:
    
    ```bash
    gcloud auth application-default login
    ```
2.  **Enable API** (if not already enabled):
    
    ```bash
    gcloud services enable aiplatform.googleapis.com
    ```

---

## 2. Client Initialization

You can initialize the client using environment variables (recommended) or by passing explicit configuration parameters.

### Option A: Environment Variables (Recommended)

Configure environment variables to let the SDK automatically resolve settings:

```bash
export GOOGLE_GENAI_USE_ENTERPRISE=true
export GOOGLE_CLOUD_PROJECT="your-project-id"
export GOOGLE_CLOUD_LOCATION="global"
```

#### Python

```python
from google import genai

# The SDK automatically picks up the environment variables
client = genai.Client()
```

#### TypeScript/JavaScript

```typescript
import { GoogleGenAI } from "@google/genai";

// The SDK automatically picks up the environment variables
const ai = new GoogleGenAI();
```

### Option B: Explicit Inline Parameters

Alternatively, pass configuration values directly inside your code:

#### Python

```python
from google import genai
import google.auth

_, project_id = google.auth.default()
client = genai.Client(enterprise=True, project=project_id, location="global")
```

#### TypeScript/JavaScript

```typescript
import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI({
    enterprise: true,
    project: "your-project-id",
    location: "global"
});
```

### Option C: Express Mode (API Key)

Recommended for lightweight scripts or environments using an API key:

#### Python

```python
from google import genai

client = genai.Client(enterprise=True, api_key="YOUR_API_KEY")
```

#### TypeScript/JavaScript

```typescript
import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI({
    enterprise: true,
    apiKey: "YOUR_API_KEY"
});
```

---

## 3. Core Interactions API Usage

### Quick Start (Single-Turn)

Submit a single prompt and read the final text response. Under the modern schema, output content is retrieved from the `steps` list.

#### Python

```python
interaction = client.interactions.create(
    model="gemini-3.8-flash",
    input="Explain serverless computing in one sentence."
)
# Use the output_text convenience accessor (combined text from the trailing model_output steps)
print(interaction.output_text)
```

#### TypeScript/JavaScript

```typescript
const interaction = await ai.interactions.create({
    model: "gemini-3.8-flash",
    input: "Explain serverless computing in one sentence."
});
console.log(interaction.output_text);
```

---

### Stateful Conversation (Multi-Turn)

Interactions are stateful by default. Store the conversation state in the cloud and reference it in the subsequent turn using `previous_interaction_id`.

#### Python

```python
# Turn 1: Introduce ourselves
# Interactions are stored by default (store=True, retained for 7 days); pass store=False to disable
# server-side retention (which also disables previous_interaction_id and background).
turn1 = client.interactions.create(
    model="gemini-3.8-flash",
    input="Hi! My name is John. I am working on AI agents.",
    store=True
)
print(f"Turn 1: {turn1.output_text}")

# Turn 2: Refer back to the stored turn state
turn2 = client.interactions.create(
    model="gemini-3.8-flash",
    input="What is my name?",
    previous_interaction_id=turn1.id
)
print(f"Turn 2: {turn2.output_text}")
```

#### TypeScript/JavaScript

```typescript
// Turn 1 (interactions are stored by default; pass store: false to disable)
const turn1 = await ai.interactions.create({
    model: "gemini-3.8-flash",
    input: "Hi! My name is John. I am working on AI agents.",
    store: true
});

// Turn 2
const turn2 = await ai.interactions.create({
    model: "gemini-3.8-flash",
    input: "What is my name?",
    previous_interaction_id: turn1.id
});
console.log(turn2.output_text);
```

---

### Real-Time Streaming

Stream responses in real-time. Passing `stream=True` returns an iterable chunk generator.

#### Python

```python
# The stream yields typed events, not full interaction snapshots. The sequence is:
# interaction.created -> (step.start -> step.delta(s) -> step.stop)+ -> interaction.completed
for event in client.interactions.create(
    model="gemini-3.8-flash",
    input="Write a short poem about debugging.",
    stream=True
):
    if event.event_type == "step.delta":
        if event.delta.type == "text":
            print(event.delta.text, end="", flush=True)
    elif event.event_type == "interaction.completed":
        print()
```

#### TypeScript/JavaScript

```typescript
// The stream yields typed events, not full interaction snapshots. The sequence is:
// interaction.created -> (step.start -> step.delta(s) -> step.stop)+ -> interaction.completed
const responseStream = await ai.interactions.create({
    model: "gemini-3.8-flash",
    input: "Write a short poem about debugging.",
    stream: true
});

for await (const event of responseStream) {
    if (event.event_type === "step.delta") {
        if (event.delta.type === "text") {
            process.stdout.write(event.delta.text);
        }
    } else if (event.event_type === "interaction.completed") {
        console.log();
    }
}
```

---

### Structured Output (Pydantic / Polymorphic `response_format`)

Retrieve structured, type-safe JSON matching a schema. Under the modern Interactions API, a polymorphic `response_format` argument directly takes the target schema structure.

#### Python

```python
from pydantic import BaseModel, Field

class Book(BaseModel):
    title: str = Field(description="The title of the book")
    author: str = Field(description="The book's author")
    year_published: int

interaction = client.interactions.create(
    model="gemini-3.8-flash",
    input="Recommend one famous sci-fi book.",
    response_format=Book
)

# The text will be a valid JSON matching the Book schema
print(interaction.output_text)
```

#### TypeScript/JavaScript

```typescript
import { Type } from "@google/genai";

const BookSchema = {
    type: Type.OBJECT,
    properties: {
        title: { type: Type.STRING, description: "The title of the book" },
        author: { type: Type.STRING, description: "The book's author" },
        yearPublished: { type: Type.INTEGER }
    },
    required: ["title", "author", "yearPublished"]
};

const interaction = await ai.interactions.create({
    model: "gemini-3.8-flash",
    input: "Recommend one famous sci-fi book.",
    response_format: BookSchema
});

console.log(interaction.output_text);
```

---

### Function Calling (Agent Tool Use)

Define local tools (functions) and submit execution results to the stateful interaction history.

#### Python

```python
import json

def get_stock_price(ticker: str) -> float:
    """Gets the stock price for a given ticker symbol."""
    if ticker.upper() == "GOOG":
        return 175.50
    return 100.0

# Turn 1: Pass tools to the model
interaction = client.interactions.create(
    model="gemini-3.8-flash",
    input="What is the stock price of GOOG?",
    tools=[get_stock_price]
)

# In the flat steps schema, a tool request is a top-level step of type
# "function_call" with flat `name` and `arguments` fields (no nested tool_calls).
for step in interaction.steps:
    if step.type == "function_call" and step.name == "get_stock_price":
        ticker_arg = step.arguments.get("ticker")
        price = get_stock_price(ticker_arg)

        # Turn 2: Submit the result back as a function_result step. Reference the
        # originating call via call_id=step.id, and pass tools again (turn-scoped).
        final_turn = client.interactions.create(
            model="gemini-3.8-flash",
            input=[
                {
                    "type": "function_result",
                    "name": step.name,
                    "call_id": step.id,
                    "result": [{"type": "text", "text": json.dumps(price)}],
                }
            ],
            tools=[get_stock_price],
            previous_interaction_id=interaction.id
        )
        print(final_turn.output_text)
```

#### TypeScript/JavaScript

```typescript
// Define local tool and flat function tool declaration
function getStockPrice({ ticker }: { ticker: string }): number {
    if (ticker.toUpperCase() === "GOOG") {
        return 175.50;
    }
    return 100.00;
}

const stockTool = {
    type: "function",
    name: "getStockPrice",
    description: "Gets the stock price for a given ticker symbol.",
    parameters: {
        type: "object",
        properties: {
            ticker: { type: "string", description: "The stock ticker symbol" }
        },
        required: ["ticker"]
    }
};

// Turn 1: Pass tools to the model
const interaction = await ai.interactions.create({
    model: "gemini-3.8-flash",
    input: "What is the stock price of GOOG?",
    tools: [stockTool]
});

// In the flat steps schema, a tool request is a top-level step of type
// "function_call" with flat `name` and `arguments` fields (no nested toolCalls).
const fcStep = interaction.steps.find(s => s.type === "function_call");
if (fcStep && fcStep.name === "getStockPrice") {
    const tickerArg = fcStep.arguments.ticker as string;
    const price = getStockPrice({ ticker: tickerArg });

    // Turn 2: Submit the result back as a function_result step. Reference the
    // originating call via call_id=fcStep.id, and pass tools again (turn-scoped).
    const finalTurn = await ai.interactions.create({
        model: "gemini-3.8-flash",
        input: [{
            type: "function_result",
            name: fcStep.name,
            call_id: fcStep.id,
            result: [{ type: "text", text: JSON.stringify(price) }]
        }],
        tools: [stockTool],
        previous_interaction_id: interaction.id
    });
    console.log(finalTurn.output_text);
}
```

---

### Agents & Long-Running Tasks

Beyond foundation models, the Interactions API provides access to specialized, autonomous agents via the `agent` parameter:

*   **`antigravity-preview-05-2026`**: Antigravity Agent — general-purpose managed agent with code execution, file management, and web browsing in a secure sandboxed Linux environment (pass `environment="remote"` to provision a sandbox).
*   **`deep-research-preview-04-2026`**: Deep Research Agent — executes multi-step web research tasks, synthesizing information from multiple sources into comprehensive reports.
*   **Custom agents**: Configured and managed via `client.agents.create()`, `list()`, `get()`, and `delete()` (pass `environment="remote"` when invoking).

Agents typically run asynchronously in the background using `background=True`. Poll the interaction status to retrieve the completed result:

#### Python

```python
import time

interaction = client.interactions.create(
    input="Analyze competitive positioning for solar energy providers.",
    agent="deep-research-preview-04-2026",
    background=True
)
print(f"Research started: {interaction.id}")

while True:
    interaction = client.interactions.get(interaction.id)
    if interaction.status == "completed":
        print(interaction.output_text)
        break
    elif interaction.status in ("failed", "cancelled"):
        print(f"Research ended with status: {interaction.status}")
        break
    time.sleep(10)
```

#### TypeScript/JavaScript

```typescript
const initialInteraction = await ai.interactions.create({
    agent: "deep-research-preview-04-2026",
    input: "Analyze competitive positioning for solar energy providers.",
    background: true
});

while (true) {
    const interaction = await ai.interactions.get(initialInteraction.id);
    if (interaction.status === "completed") {
        console.log(interaction.output_text);
        break;
    } else if (["failed", "cancelled"].includes(interaction.status)) {
        console.log(`Research ended with status: ${interaction.status}`);
        break;
    }
    await new Promise(resolve => setTimeout(resolve, 10000));
}
```

---

## 4. Accessing the Interactions API via REST

For shell-based scripts, debugging, or non-Python/JS environments, communicate with the stateful Interactions API over HTTP/REST (`curl`) at `POST https://aiplatform.googleapis.com/v1beta1/projects/{PROJECT_ID}/locations/{LOCATION}/interactions` (or `POST https://aiplatform.googleapis.com/v1beta1/locations/global/interactions` with `x-goog-api-key` for Express Mode). Pass `"model"` or `"agent"`, `"input"` steps with `"type": "user_input"`, and optional `"previous_interaction_id"`, `"background": true`, or `"stream": true` (which streams Server-Sent Events via `Content-Type: text/event-stream` and `Transfer-Encoding: chunked` that `curl` prints continuously in real time).

For complete `curl` examples (single-turn, multi-turn stateful, SSE streaming, and background managed agents) and response schemas, read [references/rest_api.md](references/rest_api.md).

---

## 5. Data Model & Step Types Reference

An `Interaction` response contains a flat `steps` timeline (`user_input`, `model_output`, `thought`, `function_call`, `function_result`, and built-in tool steps) along with convenience accessors (`output_text`, `output_image`, `output_audio`) and SSE streaming events (`interaction.created`, `step.start`, `step.delta`, `step.stop`, `interaction.completed`).

For the complete step types, content types, streaming event table, and 7-day retention rules, read [references/data_model.md](references/data_model.md).