Mistral AI Chat

Spring AI supports the various AI language models from Mistral AI. You can interact with Mistral AI language models and create a multilingual conversational assistant based on Mistral models.

Mistral AI offers an OpenAI API-compatible endpoint as well. Check the OpenAI API compatibility section to learn how to use the Spring AI OpenAI integration to talk to a Mistral endpoint.

Prerequisites

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

export SPRING_AI_MISTRALAI_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 Mistral AI 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-mistral-ai-spring-boot-starter</artifactId>
</dependency>

or to your Gradle build.gradle build file.

dependencies {
    implementation 'org.springframework.ai:spring-ai-mistral-ai-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 Mistral AI chat model.

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.on-http-codes	List of HTTP status codes that should trigger a retry (e.g. to throw TransientAiException).	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

spring.ai.retry.on-http-codes

List of HTTP status codes that should trigger a retry (e.g. to throw TransientAiException).

empty

Connection Properties

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

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

Property

Description

Default

spring.ai.mistralai.base-url

The URL to connect to

api.mistral.ai

spring.ai.mistralai.api-key

The API Key

Configuration Properties

The prefix spring.ai.mistralai.chat is the property prefix that lets you configure the chat model implementation for Mistral AI.

Property Description Default

Property	Description	Default
spring.ai.mistralai.chat.enabled	Enable Mistral AI chat model.	true
spring.ai.mistralai.chat.base-url	Optional override for the `spring.ai.mistralai.base-url` property to provide chat-specific URL.	-
spring.ai.mistralai.chat.api-key	Optional override for the `spring.ai.mistralai.api-key` to provide chat-specific API Key.	-
spring.ai.mistralai.chat.options.model	This is the Mistral AI Chat model to use	`open-mistral-7b`, `open-mixtral-8x7b`, `open-mixtral-8x22b`, `mistral-small-latest`, `mistral-large-latest`
spring.ai.mistralai.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.mistralai.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.mistralai.chat.options.safePrompt	Indicates whether to inject a security prompt before all conversations.	false
spring.ai.mistralai.chat.options.randomSeed	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.mistralai.chat.options.stop	Stop generation if this token is detected. Or if one of these tokens is detected when providing an array.	-
spring.ai.mistralai.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.mistralai.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.mistralai.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.mistralai.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.mistralai.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.mistralai.chat.options.functionCallbacks	Mistral AI Tool Function Callbacks to register with the ChatModel.	-
spring.ai.mistralai.chat.options.proxy-tool-calls	If true, the Spring AI will not handle the function calls internally, but will proxy them to the client. Then is the client’s responsibility to handle the function calls, dispatch them to the appropriate function, and return the results. If false (the default), the Spring AI will handle the function calls internally. Applicable only for chat models with function calling support	false

spring.ai.mistralai.chat.enabled

Enable Mistral AI chat model.

true

spring.ai.mistralai.chat.base-url

Optional override for the spring.ai.mistralai.base-url property to provide chat-specific URL.

spring.ai.mistralai.chat.api-key

Optional override for the spring.ai.mistralai.api-key to provide chat-specific API Key.

spring.ai.mistralai.chat.options.model

This is the Mistral AI Chat model to use

open-mistral-7b, open-mixtral-8x7b, open-mixtral-8x22b, mistral-small-latest, mistral-large-latest

spring.ai.mistralai.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.mistralai.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.mistralai.chat.options.safePrompt

Indicates whether to inject a security prompt before all conversations.

false

spring.ai.mistralai.chat.options.randomSeed

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.mistralai.chat.options.stop

Stop generation if this token is detected. Or if one of these tokens is detected when providing an array.

spring.ai.mistralai.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.mistralai.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.mistralai.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.mistralai.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.mistralai.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.mistralai.chat.options.functionCallbacks

Mistral AI Tool Function Callbacks to register with the ChatModel.

spring.ai.mistralai.chat.options.proxy-tool-calls

If true, the Spring AI will not handle the function calls internally, but will proxy them to the client. Then is the client’s responsibility to handle the function calls, dispatch them to the appropriate function, and return the results. If false (the default), the Spring AI will handle the function calls internally. Applicable only for chat models with function calling support

false

You can override the common spring.ai.mistralai.base-url and spring.ai.mistralai.api-key for the ChatModel and EmbeddingModel implementations. The spring.ai.mistralai.chat.base-url and spring.ai.mistralai.chat.api-key properties, if set, take precedence over the common properties. This is useful if you want to use different Mistral AI accounts for different models and different model endpoints.

All properties prefixed with spring.ai.mistralai.chat.options can be overridden at runtime by adding request-specific Runtime Options to the Prompt call.

Runtime Options

The MistralAiChatOptions.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 MistralAiChatModel(api, options) constructor or the spring.ai.mistralai.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 = chatModel.call(
    new Prompt(
        "Generate the names of 5 famous pirates.",
        MistralAiChatOptions.builder()
            .withModel(MistralAiApi.ChatModel.LARGE.getValue())
            .withTemperature(0.5)
        .build()
    ));

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

Function Calling

You can register custom Java functions with the MistralAiChatModel and have the Mistral AI 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 Mistral AI Function Calling.

OpenAI API Compatibility

Mistral is OpenAI API-compatible and you can use the Spring AI OpenAI client to talk to Mistrial. For this, you need to configure the OpenAI base URL to the Mistral AI platform: spring.ai.openai.chat.base-url=https://api.mistral.ai, and select a Mistral model: spring.ai.openai.chat.options.model=mistral-small-latest and set the Mistral AI API key: spring.ai.openai.chat.api-key=<YOUR MISTRAL API KEY.

Check the MistralWithOpenAiChatModelIT.java tests for examples of using Mistral over Spring AI OpenAI.

Sample Controller (Auto-configuration)

Create a new Spring Boot project and add the spring-ai-mistral-ai-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 Mistral AI chat model:

spring.ai.mistralai.api-key=YOUR_API_KEY
spring.ai.mistralai.chat.options.model=mistral-small
spring.ai.mistralai.chat.options.temperature=0.7

Replace the api-key with your Mistral AI credentials.

This will create a MistralAiChatModel implementation that you can inject into your classes. Here is an example of a simple @RestController class that uses the chat model for text generations.

@RestController
public class ChatController {

    private final MistralAiChatModel chatModel;

    @Autowired
    public ChatController(MistralAiChatModel chatModel) {
        this.chatModel = chatModel;
    }

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

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

Manual Configuration

The MistralAiChatModel implements the ChatModel and StreamingChatModel and uses the Low-level MistralAiApi Client to connect to the Mistral AI service.

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

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

or to your Gradle build.gradle build file.

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

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

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

var mistralAiApi = new MistralAiApi(System.getenv("MISTRAL_AI_API_KEY"));

var chatModel = new MistralAiChatModel(this.mistralAiApi, MistralAiChatOptions.builder()
                .withModel(MistralAiApi.ChatModel.LARGE.getValue())
                .withTemperature(0.4)
                .withMaxTokens(200)
                .build());

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

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

The MistralAiChatOptions provides the configuration information for the chat requests. The MistralAiChatOptions.Builder is a fluent options-builder.

Low-level MistralAiApi Client

The MistralAiApi provides is lightweight Java client for Mistral AI API.

Here is a simple snippet showing how to use the API programmatically:

MistralAiApi mistralAiApi = new MistralAiApi(System.getenv("MISTRAL_AI_API_KEY"));

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

// Sync request
ResponseEntity<ChatCompletion> response = this.mistralAiApi.chatCompletionEntity(
    new ChatCompletionRequest(List.of(this.chatCompletionMessage), MistralAiApi.ChatModel.LARGE.getValue(), 0.8, false));

// Streaming request
Flux<ChatCompletionChunk> streamResponse = this.mistralAiApi.chatCompletionStream(
        new ChatCompletionRequest(List.of(this.chatCompletionMessage), MistralAiApi.ChatModel.LARGE.getValue(), 0.8, true));

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

MistralAiApi Samples

The MistralAiApiIT.java tests provide some general examples of how to use the lightweight library.
The PaymentStatusFunctionCallingIT.java tests show how to use the low-level API to call tool functions. Based on the Mistral AI Function Calling tutorial.