---
title: Vertex AI
slug: /bundles-vertexai
---

import Icon from "@site/src/components/icon";
import PartialParams from '@site/docs/_partial-hidden-params.mdx';

<Icon name="Blocks" aria-hidden="true" /> [**Bundles**](/components-bundle-components) contain custom components that support specific third-party integrations with Langflow.

This page describes the components that are available in the **Vertex AI** bundle.

For more information about Vertex AI features and functionality used by Vertex AI components, see the [Vertex AI documentation](https://cloud.google.com/vertex-ai).

For other Google components, see the [**Google** bundle](/bundles-google).

## Vertex AI text generation

The **Vertex AI** component generates text using Google Vertex AI models, including the Gemini 1.5, 2.0, 2.5, and 3.0 series. The latest Gemini 3.0 models (`gemini-3-pro-preview`, `gemini-3-flash-preview`, and `gemini-3-pro-image-preview`) offer advanced reasoning and multimodal capabilities.

It can output either a **Model Response** ([`Message`](/data-types#message)) or a **Language Model** ([`LanguageModel`](/data-types#languagemodel)).

Use the **Language Model** output when you want to use a Vertex AI model as the LLM for another LLM-driven component, such as an **Agent** or **Smart Transform** component.

For more information, see [Language model components](/components-models).

### Vertex AI text generation parameters

<PartialParams />

| Name | Type | Description |
|------|------|-------------|
| credentials | File | Input parameter. JSON credentials file. Leave empty to fall back to environment variables. File type: JSON. For more information, see [Create a service account for Vertex AI authentication](#vertexai-credentials). |
| model_name | String | Input parameter. The name of the Vertex AI model to use, such as `"gemini-1.5-pro"` or `"gemini-3-pro-preview"`. Default: "gemini-1.5-pro". |
| project | String | Input parameter. The project ID. |
| location | String | Input parameter. The location for the Vertex AI API. Default: "us-central1". |
| max_output_tokens | Integer | Input parameter. The maximum number of tokens to generate. |
| max_retries | Integer | Input parameter. Maximum number of retries for API calls. Default: 1. |
| temperature | Float | Input parameter. Controls randomness in the output. Default: 0.0. |
| top_k | Integer | Input parameter. The number of highest-probability vocabulary tokens to keep for top-k-filtering. |
| top_p | Float | Input parameter. The cumulative probability of all highest-probability vocabulary tokens that are kept for nucleus sampling. Default: 0.95. |
| verbose | Boolean | Input parameter. Whether to print verbose output. Default: `false`. |

For more information about Vertex AI text generation parameters, see the [Vertex AI content generation parameters documentation](https://cloud.google.com/vertex-ai/generative-ai/docs/multimodal/content-generation-parameters#token-sampling-parameters).

## Vertex AI Embeddings

The **Vertex AI Embeddings** component is a wrapper around the [Google Vertex AI Embeddings API](https://cloud.google.com/vertex-ai/docs/generative-ai/embeddings/get-text-embeddings) for embedding generation.

For more information about using embedding model components in flows, see [Embedding model components](/components-embedding-models).

### Vertex AI Embeddings parameters

<PartialParams />

| Name | Type | Description |
|------|------|-------------|
| credentials | Credentials | Input parameter. JSON credentials file. Leave empty to fall back to environment variables. File type: JSON. For more information, see [Create a service account for Vertex AI authentication](#vertexai-credentials). |
| location | String | Input parameter. The default location to use when making API calls. Default: `us-central1`. |
| max_output_tokens | Integer | Input parameter. The token limit determines the maximum amount of text output from one prompt. Default: `128`. |
| model_name | String | Input parameter. The name of the Vertex AI large language model. Default: `text-bison`. |
| project | String | Input parameter. The default GCP project to use when making Vertex API calls. |
| request_parallelism | Integer | Input parameter. The amount of parallelism allowed for requests issued to Vertex AI models. Default: `5`. |
| temperature | Float | Input parameter. Tunes the degree of randomness in text generations. Should be a non-negative value. Default: `0`. |
| top_k | Integer | Input parameter. How the model selects tokens for output. The next token is selected from the top `k` tokens. Default: `40`. |
| top_p | Float | Input parameter. Tokens are selected from the most probable to least until the sum of their probabilities exceeds the top `p` value. Default: `0.95`. |
| tuned_model_name | String | Input parameter. The name of a tuned model. If provided, `model_name` is ignored. |
| verbose | Boolean | Input parameter. This parameter controls the level of detail in the output. When set to `true`, it prints internal states of the chain to help debug. Default: `false`. |
| embeddings | Embeddings | Output parameter. An instance for generating embeddings using Vertex AI. |

## Create a service account for Vertex AI authentication {#vertexai-credentials}

The **Vertex AI Embeddings** and **Vertex AI** components authenticate with the [Google Vertex AI API](https://console.cloud.google.com/marketplace/product/google/aiplatform.googleapis.com) using a service account JSON file.

These components require that you provide a service account JSON file in the **Credentials** parameter (`credentials`).
You can either provide the file directly in your component's settings or you can use a [`GOOGLE_APPLICATION_CREDENTIALS` environment variable](https://cloud.google.com/docs/authentication/application-default-credentials) to reference the path to your JSON file.

The following steps explain how to create a service account for Langflow, create a service account JSON key file, and then use the JSON key file in Langflow:

1. If you haven't done so already, [enable the Vertex AI APIs in your Google Cloud project](https://cloud.google.com/vertex-ai/docs/start/cloud-environment).

2. Create a [service account](https://cloud.google.com/iam/docs/service-account-overview) in your Google Cloud project.

    It is recommended that you [create a custom service account for Vertex AI](https://cloud.google.com/vertex-ai/docs/general/custom-service-account) because Langflow uses this account to access the Vertex AI APIs.

3. Assign the **Vertex AI Service Agent** role to the service account.

    This role allows Langflow to access Vertex AI resources.
    For more information, see [Vertex AI access control with IAM](https://cloud.google.com/vertex-ai/docs/general/access-control).

4. [Create a service account key](https://cloud.google.com/iam/docs/keys-create-delete#console) in JSON format for your Langflow Vertex AI service account.

    When you click **Create**, the JSON key file is downloaded.

5. In Langflow, create or open a flow with the **Vertex AI** or **Vertex AI Embeddings** component.

6. In the component's **Credentials** field, do one of the following:

    * Select your service account JSON file directly.

    * Leave the **Credentials** field empty if you want to pull the key file from an environment variable.
    Then, you must provide the path to your JSON file in a `GOOGLE_APPLICATION_CREDENTIALS` environment variable that is set somewhere relative to your Langflow instance.
    For example, you can set the environment variable in your terminal, your Langflow `.env` file, or otherwise in the environment where your Langflow server or application runs.

    ![Select a local JSON key file for the Vertex AI component](/img/configure-vertex-ai-credentials-in-langflow.gif)

7. Run your flow to verify that Langflow can use the service account credentials successfully.

    For example, in a flow with **Chat Input**, **Chat Output**, and **Vertex AI** components, you can open the **Playground** and try chatting with the LLM.
    If the LLM responds, then the credentials are configured correctly.