Package com.google.genkit.plugins.middleware

Class SimulateSystemPromptMiddleware

java.lang.Object

com.google.genkit.ai.middleware.BaseGenerationMiddleware

com.google.genkit.plugins.middleware.SimulateSystemPromptMiddleware

All Implemented Interfaces:

GenerationMiddleware

public class SimulateSystemPromptMiddleware
extends BaseGenerationMiddleware

Rewrites a system message into a user/model exchange, for models that do not natively support system prompts.

Wraps the wrapGenerate hook: each system message is replaced by a user message (SimulateSystemPromptMiddleware.Options.preface followed by the original system content) and a model message (SimulateSystemPromptMiddleware.Options.acknowledgement). Non-system messages are passed through unchanged.

Mirrors the JS simulateSystemPrompt model middleware.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SimulateSystemPromptMiddleware.Options	Configuration parameters for SimulateSystemPromptMiddleware.

Constructor Summary

Constructors

Constructor	Description
SimulateSystemPromptMiddleware(SimulateSystemPromptMiddleware.Options options)

Method Summary

Modifier and Type	Method	Description
String	name()	Returns the middleware's unique identifier.
GenerationMiddleware	newInstance()	Returns a fresh instance for each generate() call, enabling per-invocation state.
ModelResponse	wrapGenerate(ActionContext ctx, GenerateParams params, GenerateNext next)	Wraps each iteration of the generate tool loop.

Methods inherited from class com.google.genkit.ai.middleware.BaseGenerationMiddleware

tools, wrapModel, wrapTool

Methods inherited from class java.lang.Object

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

Constructor Details

SimulateSystemPromptMiddleware

public SimulateSystemPromptMiddleware(SimulateSystemPromptMiddleware.Options options)

Method Details

name

public String name()

Description copied from interface: GenerationMiddleware

Returns the middleware's unique identifier.

newInstance

public GenerationMiddleware newInstance()

Description copied from interface: GenerationMiddleware

Returns a fresh instance for each generate() call, enabling per-invocation state.

Stable state (e.g., API keys, configuration) should be preserved. Per-request state (e.g., counters) should be reset.

wrapGenerate

public ModelResponse wrapGenerate(ActionContext ctx,
 GenerateParams params,
 GenerateNext next)
                           throws GenkitException

Description copied from interface: GenerationMiddleware

Wraps each iteration of the generate tool loop.

Specified by:

wrapGenerate in interface GenerationMiddleware

Overrides:

wrapGenerate in class BaseGenerationMiddleware

Parameters:

ctx - the action context

params - the generate parameters including the current request and iteration

next - the next function in the chain

Returns:

the model response

Throws:

GenkitException - if processing fails