Class DecisionServices

java.lang.Object

dev.langchain4j.service.decision.DecisionServices

@Experimental
public final class DecisionServices
extends Object

Creates implementations of Java interfaces whose methods are answered by a DecisionModel.

The parameters of a method are sent to the model as the input, keyed by parameter name, and the return type determines the questions:

• boolean: a yes/no question, true when the probability of "yes" reaches the threshold (see DecisionServices.Builder.thresholdProvider(ThresholdProvider))
• YesNoAnswer: a yes/no question, with the probability of "yes"
• an enum: a question choosing one of its constants
• Choice<enum>: the same, with the probability of each constant
• Scale<enum>: a question placing the input on an ordered scale, whose levels are the constants from the first (lowest) to the last (highest)
• an object or record whose fields are of the types above: one question per field, in a single call

Any of these can be wrapped in DecisionResult (to also get the raw response) and/or in CompletableFuture or CompletionStage (to call the model asynchronously).

A parameter of type DecisionRequestParameters is not sent as part of the input: it sets the parameters of the call, such as the model name, overriding the model's defaults.

The question is set with @Decide: on the method, or on the fields of the returned object. The meaning of enum constants is described with @Description:

enum Team {
    @Description("Payments, invoices, refunds") BILLING,
    @Description("Problems using the product") SUPPORT
}

class Triage {
    @Decide("Which team should handle this ticket?") Team team;
    @Decide("Does this need attention today?") boolean urgent;
}

interface SupportDesk {

    Triage triage(String ticket);

    @Decide("Is this message spam?")
    YesNoAnswer isSpam(String message);

    @Decide("Which team should handle this ticket?")
    Choice<Team> route(String ticket);
}

SupportDesk supportDesk = DecisionServices.builder(SupportDesk.class)
        .decisionModel(decisionModel)
        .build();

The created implementation holds no state of its own, so it can be shared between threads.

Since:

1.21.0

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	DecisionServices.Builder<T>	Builds decision services.

Method Summary

Modifier and Type	Method	Description
static <T> DecisionServices.Builder<T>	builder(Class<T> serviceInterface)	Creates a builder for an implementation of the given interface.
static <T> T	create(Class<T> serviceInterface, DecisionModel decisionModel)	Creates an implementation of the given interface whose methods are answered by the given decision model.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

create

public static <T> T create(Class<T> serviceInterface,
 DecisionModel decisionModel)

Creates an implementation of the given interface whose methods are answered by the given decision model. Equivalent to builder(serviceInterface).decisionModel(decisionModel).build().

builder

public static <T> DecisionServices.Builder<T> builder(Class<T> serviceInterface)

Creates a builder for an implementation of the given interface.