ML & AI Handlers

ML & AI handlers allow incorporation of AI agent and machine learning capabilities

ML & AI handlers add model inference, LLM orchestration, embeddings, and AI protocol support.

Use this page for handler-level details:

• Class names

• Handler parameters

• Runtime dependencies

• Built-in variants

Use ML & AI Actions for action-level saga step fields and parameters.

Use ML Models

Classes:

• com.rierino.handler.tensor.TensorScoreEventHandler

• com.rierino.handler.onnx.OnnxScoreEventHandler

• com.rierino.handler.pmml.PMMLScoreEventHandler

• com.rierino.handler.opennlp.OpenNLPScoreEventHandler

Runs real-time inference using pre-trained ML models.

Handler parameters

Parameter	Definition	Example	Default
model.state	State manager with model configurations	model	-
model.id	Model id to run on this handler instance	recommendation	-
model.store.system	System used to store model assets	hdfs_default	-
model.local.dir	Local directory used for model assets	/tmp	java.io.tmpdir

This handler supports caching.

Runtime dependencies

TensorFlow:

implementation (group:'com.rierino.custom', name: 'tensor', version:"${rierinoVersion}")

ONNX:

implementation (group:'com.rierino.custom', name: 'onnx', version:"${rierinoVersion}")

PMML:

implementation (group:'com.rierino.custom', name: 'pmml', version:"${rierinoVersion}")

OpenNLP:

implementation (group:'com.rierino.custom', name: 'opennlp', version:"${rierinoVersion}")

Action details: Use ML Models

Use GenAI Models

Class: com.rierino.handler.rai.RAIModelEventHandler

Legacy: com.rierino.handler.langchain4j.LangChainModelEventHandler

Runs LLM chat and image generation flows through different LLM model providers.

The legacy LangChain handler is replaced by RAI handler, which provides a more efficient implementation with more flexible runtime & chat model configurations.

Handler parameters

Parameter	Definition	Example	Default
model.state	State manager with model configurations	genai_model	-
model.domain	Model domain to include	chat	-
saga.handler	Saga handler used for tool sagas	-	saga
saga.state	State manager with saga definitions used as tools	-	saga
schema.state	State manager with schema definitions used for state tools	-	schema
script.handler	Event handler that is used for executing scripts generated by AI	-	script

Action details: Use GenAI Models

Perform Text Embedding

Class: com.rierino.handler.rai.EmbeddingEventHandler

Legacy: com.rierino.handler.langchain4j.EmbeddingEventHandler

Creates embeddings for search and retrieval use cases.4

The legacy LangChain handler is replaced by RAI handler, which provides a more efficient implementation with more flexible configurations.

Handler parameters

For ONNX-based models:

Parameter	Definition	Example	Default
model.store.system	System to fetch ONNX model files from	model_fs	default Hugging Face repo
model.path	Model file path	/model.onnx	default ONNX model
tokenizer.path	Tokenizer file path	/tokenizer.json	default tokenizer
model.local.dir	Local directory for downloaded model files	/app/models	system temp dir

For custom embedding providers:

Parameter	Definition	Example	Default
embedding.class	Java class implementing the embedding provider	dev.langchain4j.model.openai.OpenAiEmbeddingModel	-
embeddingMethods	Method configuration passed to the embedding class	{"apiKey":"xxx"}	-

Action details: Perform Text Embedding

Service MCP Requests

Class: com.rierino.handler.mcp.McpServerEventHandler

Exposes existing microservice capabilities over MCP.

Handler parameters

Parameter	Definition	Example	Default
server.state	State manager with MCP server configurations	mcp_server	genai_model
server.domain	Server domain to include	procurement	-
saga.handler	Saga handler used for tool sagas	ai_saga	saga
saga.state	State manager with saga definitions used as tools	ai_saga	saga

Action details: Service MCP Requests

Service A2A Requests

Class: com.rierino.handler.a2a.A2AServerEventHandler

Exposes existing microservice capabilities over A2A.

Handler parameters

Parameter	Definition	Example	Default
server.state	State manager with A2A server configurations	mcp_server	genai_model
server.domain	Server domain to include	procurement	-
saga.handler	Saga handler used for tool sagas	ai_saga	saga

Action details: Service A2A Requests