OpenAI Chat

Spring AI supports ChatGPT, the AI language model by OpenAI. ChatGPT has been instrumental in sparking interest in AI-driven text generation, thanks to its creation of industry-leading text generation models and embeddings.

Prerequisites

You will need to create an API with OpenAI to access ChatGPT models. Create an account at OpenAI signup page and generate the token on the API Keys page. The Spring AI project defines a configuration property named spring.ai.openai.api-key that you should set to the value of the API Key obtained from openai.com. Exporting an environment variable is one way to set that configuration property:

export SPRING_AI_OPENAI_API_KEY=<INSERT KEY HERE>

Add Repositories and BOM

Spring AI artifacts are published in Spring Milestone and Snapshot repositories. Refer to the Repositories section to add these repositories to your build system.

To help with dependency management, Spring AI provides a BOM (bill of materials) to ensure that a consistent version of Spring AI is used throughout the entire project. Refer to the Dependency Management section to add the Spring AI BOM to your build system.

Auto-configuration

Spring AI provides Spring Boot auto-configuration for the OpenAI Chat Client. To enable it add the following dependency to your project’s Maven pom.xml file:

<dependency>
    <groupId>org.springframework.ai</groupId>
    <artifactId>spring-ai-openai-spring-boot-starter</artifactId>
</dependency>

or to your Gradle build.gradle build file.

dependencies {
    implementation 'org.springframework.ai:spring-ai-openai-spring-boot-starter'
}

Refer to the Dependency Management section to add the Spring AI BOM to your build file.

Chat Properties

Retry Properties

The prefix spring.ai.retry is used as the property prefix that lets you configure the retry mechanism for the OpenAI Chat client.

Property Description Default

Property	Description	Default
spring.ai.retry.max-attempts	Maximum number of retry attempts.	10
spring.ai.retry.backoff.initial-interval	Initial sleep duration for the exponential backoff policy.	2 sec.
spring.ai.retry.backoff.multiplier	Backoff interval multiplier.	5
spring.ai.retry.backoff.max-interval	Maximum backoff duration.	3 min.
spring.ai.retry.on-client-errors	If false, throw a NonTransientAiException, and do not attempt retry for `4xx` client error codes	false
spring.ai.retry.exclude-on-http-codes	List of HTTP status codes that should not trigger a retry (e.g. to throw NonTransientAiException).	empty

spring.ai.retry.max-attempts

Maximum number of retry attempts.

spring.ai.retry.backoff.initial-interval

Initial sleep duration for the exponential backoff policy.

2 sec.

spring.ai.retry.backoff.multiplier

Backoff interval multiplier.

spring.ai.retry.backoff.max-interval

Maximum backoff duration.

3 min.

spring.ai.retry.on-client-errors

If false, throw a NonTransientAiException, and do not attempt retry for 4xx client error codes

false

spring.ai.retry.exclude-on-http-codes

List of HTTP status codes that should not trigger a retry (e.g. to throw NonTransientAiException).

empty

Connection Properties

The prefix spring.ai.openai is used as the property prefix that lets you connect to OpenAI.

Property	Description	Default
spring.ai.openai.base-url	The URL to connect to	api.openai.com
spring.ai.openai.api-key	The API Key	-

Property

Description

Default

spring.ai.openai.base-url

The URL to connect to

api.openai.com

spring.ai.openai.api-key

The API Key

Configuration Properties

The prefix spring.ai.openai.chat is the property prefix that lets you configure the chat client implementation for OpenAI.

Property Description Default

Property	Description	Default
spring.ai.openai.chat.enabled	Enable OpenAI chat client.	true
spring.ai.openai.chat.base-url	Optional overrides the spring.ai.openai.base-url to provide chat specific url	-
spring.ai.openai.chat.api-key	Optional overrides the spring.ai.openai.api-key to provide chat specific api-key	-
spring.ai.openai.chat.options.model	This is the OpenAI Chat model to use	`gpt-3.5-turbo` (the `gpt-3.5-turbo`, `gpt-4`, and `gpt-4-32k` point to the latest model versions)
spring.ai.openai.chat.options.temperature	The sampling temperature to use that controls the apparent creativity of generated completions. Higher values will make output more random while lower values will make results more focused and deterministic. It is not recommended to modify temperature and top_p for the same completions request as the interaction of these two settings is difficult to predict.	0.8
spring.ai.openai.chat.options.frequencyPenalty	Number between -2.0 and 2.0. Positive values penalize new tokens based on their existing frequency in the text so far, decreasing the model’s likelihood to repeat the same line verbatim.	0.0f
spring.ai.openai.chat.options.logitBias	Modify the likelihood of specified tokens appearing in the completion.	-
spring.ai.openai.chat.options.maxTokens	The maximum number of tokens to generate in the chat completion. The total length of input tokens and generated tokens is limited by the model’s context length.	-
spring.ai.openai.chat.options.n	How many chat completion choices to generate for each input message. Note that you will be charged based on the number of generated tokens across all of the choices. Keep n as 1 to minimize costs.	1
spring.ai.openai.chat.options.presencePenalty	Number between -2.0 and 2.0. Positive values penalize new tokens based on whether they appear in the text so far, increasing the model’s likelihood to talk about new topics.	-
spring.ai.openai.chat.options.responseFormat	An object specifying the format that the model must output. Setting to `{ "type": "json_object" }` enables JSON mode, which guarantees the message the model generates is valid JSON.	-
spring.ai.openai.chat.options.seed	This feature is in Beta. If specified, our system will make a best effort to sample deterministically, such that repeated requests with the same seed and parameters should return the same result.	-
spring.ai.openai.chat.options.stop	Up to 4 sequences where the API will stop generating further tokens.	-
spring.ai.openai.chat.options.topP	An alternative to sampling with temperature, called nucleus sampling, where the model considers the results of the tokens with top_p probability mass. So 0.1 means only the tokens comprising the top 10% probability mass are considered. We generally recommend altering this or temperature but not both.	-
spring.ai.openai.chat.options.tools	A list of tools the model may call. Currently, only functions are supported as a tool. Use this to provide a list of functions the model may generate JSON inputs for.	-
spring.ai.openai.chat.options.toolChoice	Controls which (if any) function is called by the model. none means the model will not call a function and instead generates a message. auto means the model can pick between generating a message or calling a function. Specifying a particular function via {"type: "function", "function": {"name": "my_function"}} forces the model to call that function. none is the default when no functions are present. auto is the default if functions are present.	-
spring.ai.openai.chat.options.user	A unique identifier representing your end-user, which can help OpenAI to monitor and detect abuse.	-
spring.ai.openai.chat.options.functions	List of functions, identified by their names, to enable for function calling in a single prompt requests. Functions with those names must exist in the functionCallbacks registry.	-

spring.ai.openai.chat.enabled

Enable OpenAI chat client.

true

spring.ai.openai.chat.base-url

Optional overrides the spring.ai.openai.base-url to provide chat specific url

spring.ai.openai.chat.api-key

Optional overrides the spring.ai.openai.api-key to provide chat specific api-key

spring.ai.openai.chat.options.model

This is the OpenAI Chat model to use

gpt-3.5-turbo (the gpt-3.5-turbo, gpt-4, and gpt-4-32k point to the latest model versions)

spring.ai.openai.chat.options.temperature

The sampling temperature to use that controls the apparent creativity of generated completions. Higher values will make output more random while lower values will make results more focused and deterministic. It is not recommended to modify temperature and top_p for the same completions request as the interaction of these two settings is difficult to predict.

0.8

spring.ai.openai.chat.options.frequencyPenalty

Number between -2.0 and 2.0. Positive values penalize new tokens based on their existing frequency in the text so far, decreasing the model’s likelihood to repeat the same line verbatim.

0.0f

spring.ai.openai.chat.options.logitBias

Modify the likelihood of specified tokens appearing in the completion.

spring.ai.openai.chat.options.maxTokens

The maximum number of tokens to generate in the chat completion. The total length of input tokens and generated tokens is limited by the model’s context length.

spring.ai.openai.chat.options.n

How many chat completion choices to generate for each input message. Note that you will be charged based on the number of generated tokens across all of the choices. Keep n as 1 to minimize costs.

spring.ai.openai.chat.options.presencePenalty

Number between -2.0 and 2.0. Positive values penalize new tokens based on whether they appear in the text so far, increasing the model’s likelihood to talk about new topics.

spring.ai.openai.chat.options.responseFormat

An object specifying the format that the model must output. Setting to { "type": "json_object" } enables JSON mode, which guarantees the message the model generates is valid JSON.

spring.ai.openai.chat.options.seed

This feature is in Beta. If specified, our system will make a best effort to sample deterministically, such that repeated requests with the same seed and parameters should return the same result.

spring.ai.openai.chat.options.stop

Up to 4 sequences where the API will stop generating further tokens.

spring.ai.openai.chat.options.topP

An alternative to sampling with temperature, called nucleus sampling, where the model considers the results of the tokens with top_p probability mass. So 0.1 means only the tokens comprising the top 10% probability mass are considered. We generally recommend altering this or temperature but not both.

spring.ai.openai.chat.options.tools

A list of tools the model may call. Currently, only functions are supported as a tool. Use this to provide a list of functions the model may generate JSON inputs for.

spring.ai.openai.chat.options.toolChoice

Controls which (if any) function is called by the model. none means the model will not call a function and instead generates a message. auto means the model can pick between generating a message or calling a function. Specifying a particular function via {"type: "function", "function": {"name": "my_function"}} forces the model to call that function. none is the default when no functions are present. auto is the default if functions are present.

spring.ai.openai.chat.options.user

A unique identifier representing your end-user, which can help OpenAI to monitor and detect abuse.

spring.ai.openai.chat.options.functions

List of functions, identified by their names, to enable for function calling in a single prompt requests. Functions with those names must exist in the functionCallbacks registry.

You can override the common spring.ai.openai.base-url and spring.ai.openai.api-key for the ChatClient and EmbeddingClient implementations. The spring.ai.openai.chat.base-url and spring.ai.openai.chat.api-key properties if set take precedence over the common properties. This is useful if you want to use different OpenAI accounts for different models and different model endpoints.

All properties prefixed with spring.ai.openai.chat.options can be overridden at runtime by adding a request specific Chat Options to the Prompt call.

Chat Options

The OpenAiChatOptions.java provides model configurations, such as the model to use, the temperature, the frequency penalty, etc.

On start-up, the default options can be configured with the OpenAiChatClient(api, options) constructor or the spring.ai.openai.chat.options.* properties.

At run-time you can override the default options by adding new, request specific, options to the Prompt call. For example to override the default model and temperature for a specific request:

ChatResponse response = chatClient.call(
    new Prompt(
        "Generate the names of 5 famous pirates.",
        OpenAiChatOptions.builder()
            .withModel("gpt-4-32k")
            .withTemperature(0.4)
        .build()
    ));

In addition to the model specific OpenAiChatOptions you can use a portable ChatOptions instance, created with the ChatOptionsBuilder#builder().

Function Calling

You can register custom Java functions with the OpenAiChatClient and have the OpenAI model intelligently choose to output a JSON object containing arguments to call one or many of the registered functions. This is a powerful technique to connect the LLM capabilities with external tools and APIs. Read more about OpenAI Function Calling.

Sample Controller (Auto-configuration)

Create a new Spring Boot project and add the spring-ai-openai-spring-boot-starter to your pom (or gradle) dependencies.

Add a application.properties file, under the src/main/resources directory, to enable and configure the OpenAi Chat client:

spring.ai.openai.api-key=YOUR_API_KEY
spring.ai.openai.chat.options.model=gpt-3.5-turbo
spring.ai.openai.chat.options.temperature=0.7

replace the api-key with your OpenAI credentials.

This will create a OpenAiChatClient implementation that you can inject into your class. Here is an example of a simple @Controller class that uses the chat client for text generations.

@RestController
public class ChatController {

    private final OpenAiChatClient chatClient;

    @Autowired
    public ChatController(OpenAiChatClient chatClient) {
        this.chatClient = chatClient;
    }

    @GetMapping("/ai/generate")
    public Map generate(@RequestParam(value = "message", defaultValue = "Tell me a joke") String message) {
        return Map.of("generation", chatClient.call(message));
    }

    @GetMapping("/ai/generateStream")
	public Flux<ChatResponse> generateStream(@RequestParam(value = "message", defaultValue = "Tell me a joke") String message) {
        Prompt prompt = new Prompt(new UserMessage(message));
        return chatClient.stream(prompt);
    }
}

Manual Configuration

The OpenAiChatClient implements the ChatClient and StreamingChatClient and uses the Low-level OpenAiApi Client to connect to the OpenAI service.

Add the spring-ai-openai dependency to your project’s Maven pom.xml file:

<dependency>
    <groupId>org.springframework.ai</groupId>
    <artifactId>spring-ai-openai</artifactId>
</dependency>

or to your Gradle build.gradle build file.

dependencies {
    implementation 'org.springframework.ai:spring-ai-openai'
}

Refer to the Dependency Management section to add the Spring AI BOM to your build file.

Next, create a OpenAiChatClient and use it for text generations:

var openAiApi = new OpenAiApi(System.getenv("OPENAI_API_KEY"));

var chatClient = new OpenAiChatClient(openAiApi)
    .withDefaultOptions(OpenAiChatOptions.builder()
            .withModel("gpt-35-turbo")
            .withTemperature(0.4)
            .withMaxTokens(200)
        .build());

ChatResponse response = chatClient.call(
    new Prompt("Generate the names of 5 famous pirates."));

// Or with streaming responses
Flux<ChatResponse> response = chatClient.stream(
    new Prompt("Generate the names of 5 famous pirates."));

The OpenAiChatOptions provides the configuration information for the chat requests. The OpenAiChatOptions.Builder is fluent options builder.

Low-level OpenAiApi Client

The OpenAiApi provides is lightweight Java client for OpenAI Chat API OpenAI Chat API.

Following class diagram illustrates the OpenAiApi chat interfaces and building blocks:

Here is a simple snippet how to use the api programmatically:

OpenAiApi openAiApi =
    new OpenAiApi(System.getenv("OPENAI_API_KEY"));

ChatCompletionMessage chatCompletionMessage =
    new ChatCompletionMessage("Hello world", Role.USER);

// Sync request
ResponseEntity<ChatCompletion> response = openAiApi.chatCompletionEntity(
    new ChatCompletionRequest(List.of(chatCompletionMessage), "gpt-3.5-turbo", 0.8f, false));

// Streaming request
Flux<ChatCompletionChunk> streamResponse = openAiApi.chatCompletionStream(
        new ChatCompletionRequest(List.of(chatCompletionMessage), "gpt-3.5-turbo", 0.8f, true));

Follow the OpenAiApi.java's JavaDoc for further information.

Example Code

The OpenAiApiIT.java test provides some general examples how to use the lightweight library.
The OpenAiApiToolFunctionCallIT.java test shows how to use the low-level API to call tool functions. Based on the OpenAI Function Calling tutorial.