tessl/maven-io-quarkiverse-langchain4j--quarkus-langchain4j-watsonx

Quarkus extension for integrating IBM watsonx.ai foundation models with LangChain4j. Provides chat models, generation models, streaming models, embedding models, and scoring models for IBM watsonx.ai. Includes comprehensive configuration options, support for tool/function calling, text extraction from documents in Cloud Object Storage, and experimental built-in services for Google search, weather, and web crawling. Designed for enterprise Java applications using the Quarkus framework with built-in dependency injection and native compilation support.

Overview

Eval results

Files

Generation Models

Name: tessl/maven-io-quarkiverse-langchain4j--quarkus-langchain4j-watsonx
Author: tessl

Legacy text generation models using the Watsonx generation API without tool/function calling support. These models provide backward compatibility with older Watsonx generation endpoints and offer different parameter controls compared to chat models. Both synchronous and streaming variants are available.

Capabilities

Synchronous Generation Model

Execute synchronous text generation with legacy generation parameters and decoding methods.

public class WatsonxGenerationModel implements dev.langchain4j.model.chat.ChatModel {
    public static Builder builder();
    public ChatResponse doChat(ChatRequest chatRequest);
    public List<ChatModelListener> listeners();
    public ChatRequestParameters defaultRequestParameters();
    public Set<Capability> supportedCapabilities();
    public WatsonxRestApi getClient();
    public String getModelId();
    public String getProjectId();
    public String getSpaceId();
    public String getVersion();
}

Supported Capabilities:

Returns empty set (no tool support or JSON schema support)

Example Usage:

import io.quarkiverse.langchain4j.watsonx.WatsonxGenerationModel;
import dev.langchain4j.data.message.UserMessage;
import dev.langchain4j.model.chat.response.ChatResponse;
import java.net.URL;

WatsonxGenerationModel model = WatsonxGenerationModel.builder()
    .modelId("meta-llama/llama-4-maverick-17b-128e-instruct-fp8")
    .url(new URL("https://us-south.ml.cloud.ibm.com"))
    .projectId("your-project-id")
    .tokenGenerator(tokenGenerator)
    .decodingMethod("sample")
    .temperature(0.7)
    .maxNewTokens(500)
    .topK(50)
    .topP(0.9)
    .repetitionPenalty(1.1)
    .build();

ChatResponse response = model.chat(UserMessage.from("Write a short poem about nature"));
String generatedText = response.aiMessage().text();

Multi-prompt Generation:

import dev.langchain4j.data.message.ChatMessage;
import java.util.List;

// Multiple prompts are joined using the promptJoiner
WatsonxGenerationModel model = WatsonxGenerationModel.builder()
    .promptJoiner("\n---\n")
    .build();

List<ChatMessage> messages = List.of(
    UserMessage.from("First prompt"),
    UserMessage.from("Second prompt")
);

ChatResponse response = model.chat(messages);
// Prompts are joined: "First prompt\n---\nSecond prompt"

Streaming Generation Model

Stream text generation responses in real-time for improved user experience.

public class WatsonxGenerationStreamingModel implements dev.langchain4j.model.chat.StreamingChatModel {
    public static Builder builder();
    public void doChat(ChatRequest chatRequest, StreamingChatResponseHandler handler);
    public List<ChatModelListener> listeners();
    public ChatRequestParameters defaultRequestParameters();
    public Set<Capability> supportedCapabilities();
    public WatsonxRestApi getClient();
    public String getModelId();
    public String getProjectId();
    public String getSpaceId();
    public String getVersion();
}

Example Usage:

import io.quarkiverse.langchain4j.watsonx.WatsonxGenerationStreamingModel;
import dev.langchain4j.model.chat.request.ChatRequest;
import dev.langchain4j.model.chat.response.StreamingChatResponseHandler;

WatsonxGenerationStreamingModel streamingModel = WatsonxGenerationStreamingModel.builder()
    .modelId("meta-llama/llama-4-maverick-17b-128e-instruct-fp8")
    .url(new URL("https://us-south.ml.cloud.ibm.com"))
    .projectId("your-project-id")
    .tokenGenerator(tokenGenerator)
    .temperature(0.8)
    .maxNewTokens(1000)
    .build();

streamingModel.chat(
    ChatRequest.builder()
        .messages(List.of(UserMessage.from("Tell me a story")))
        .build(),
    new StreamingChatResponseHandler() {
        @Override
        public void onPartialResponse(String partialResponse) {
            System.out.print(partialResponse);
        }

        @Override
        public void onComplete(ChatResponse response) {
            System.out.println("\nGeneration complete!");
            System.out.println("Tokens: " + response.tokenUsage().totalTokens());
            System.out.println("Stop reason: " + response.finishReason());
        }

        @Override
        public void onError(Throwable error) {
            System.err.println("Error: " + error.getMessage());
        }
    }
);

Generation Model Builder

Configure generation models with legacy Watsonx generation parameters.

public static class Builder extends Watsonx.Builder<WatsonxGenerationModel, Builder> {
    // Inherited base parameters
    public Builder modelId(String modelId);
    public Builder version(String version);
    public Builder spaceId(String spaceId);
    public Builder projectId(String projectId);
    public Builder url(URL url);
    public Builder timeout(Duration timeout);
    public Builder tokenGenerator(TokenGenerator tokenGenerator);
    public Builder logRequests(boolean logRequests);
    public Builder logResponses(boolean logResponses);
    public Builder logCurl(boolean logCurl);
    public Builder listeners(List<ChatModelListener> listeners);

    // Generation-specific parameters
    public Builder decodingMethod(String decodingMethod);
    public Builder decayFactor(Double decayFactor);
    public Builder startIndex(Integer startIndex);
    public Builder minNewTokens(Integer minNewTokens);
    public Builder maxNewTokens(Integer maxNewTokens);
    public Builder temperature(Double temperature);
    public Builder topK(Integer topK);
    public Builder topP(Double topP);
    public Builder randomSeed(Integer randomSeed);
    public Builder repetitionPenalty(Double repetitionPenalty);
    public Builder stopSequences(List<String> stopSequences);
    public Builder truncateInputTokens(Integer truncateInputTokens);
    public Builder includeStopSequence(Boolean includeStopSequence);
    public Builder promptJoiner(String promptJoiner);

    public WatsonxGenerationModel build();
}

Parameter Details:

modelId (String, required): Watsonx model identifier
- Default: "meta-llama/llama-4-maverick-17b-128e-instruct-fp8"
- Examples: "ibm/granite-13b-instruct-v2", "meta-llama/llama-3-70b-instruct"
version (String): API version
- Default: "2025-04-23"
- Format: "YYYY-MM-DD"
spaceId (String): Deployment space ID (mutually exclusive with projectId)
projectId (String): Project ID (mutually exclusive with spaceId)
url (URL, required): Watsonx API base URL
- US South: https://us-south.ml.cloud.ibm.com
- EU Germany: https://eu-de.ml.cloud.ibm.com
- Japan: https://jp-tok.ml.cloud.ibm.com
timeout (Duration): Request timeout
- Default: 10 seconds
tokenGenerator (TokenGenerator, required): Handles IBM Cloud IAM authentication
logRequests (boolean): Enable request body logging
- Default: false
logResponses (boolean): Enable response body logging
- Default: false
logCurl (boolean): Log requests as cURL commands
- Default: false
listeners (List<ChatModelListener>): Request/response event listeners
decodingMethod (String): Decoding strategy for token selection
- Values: "greedy", "sample"
- Default: "greedy"
- "greedy": Always select highest probability token
- "sample": Sample from probability distribution
decayFactor (Double): Length penalty decay factor
- Range: > 1.0
- Applied as part of length penalty calculation
- Higher values increase penalty for longer sequences
startIndex (Integer): Length penalty start index
- Range: >= 0
- Token position where length penalty begins
- Tokens before this index are not penalized
minNewTokens (Integer): Minimum number of tokens to generate
- Default: 0
- Forces model to generate at least this many tokens
- Useful for ensuring minimum response length
maxNewTokens (Integer): Maximum number of tokens to generate
- Default: 200
- Stops generation after this many tokens
- Does not include input prompt tokens
temperature (Double): Sampling temperature
- Range: 0.0 to 2.0
- Default: 1.0
- Lower = more focused/deterministic
- Higher = more creative/random
- Only applies when decodingMethod="sample"
topK (Integer): Top-K sampling parameter
- Range: 1 to 100
- Limits sampling to top K most probable tokens
- Only applies when decodingMethod="sample"
topP (Double): Nucleus sampling parameter
- Range: 0.0 to 1.0
- Limits sampling to tokens in top P probability mass
- Only applies when decodingMethod="sample"
randomSeed (Integer): Random seed for reproducibility
- Range: >= 1
- Makes sampling deterministic for debugging
- Same seed + parameters = same output
repetitionPenalty (Double): Penalty for repeated tokens
- Range: 1.0 to 2.0
- Default: 1.0 (no penalty)
- Higher values discourage repetition
- 1.5 is a typical value for reducing repetition
stopSequences (List<String>): Stop sequences (max 6)
- Generation stops when any sequence is encountered
- Stop sequence can optionally be included in output
truncateInputTokens (Integer): Truncate input if exceeds limit
- Default: 0 (no truncation)
- Truncates from left if input exceeds this limit
- Useful for staying within model context limits
includeStopSequence (Boolean): Include stop sequence in output
- Default: false
- If true, matched stop sequence is included in generated text
promptJoiner (String): String to join multiple prompts
- Default: "\n"
- Used when multiple messages are provided
- Joins message texts with this separator

Complete Builder Example:

WatsonxGenerationModel model = WatsonxGenerationModel.builder()
    .modelId("meta-llama/llama-4-maverick-17b-128e-instruct-fp8")
    .url(new URL("https://us-south.ml.cloud.ibm.com"))
    .projectId("abc123")
    .tokenGenerator(tokenGenerator)
    .decodingMethod("sample")
    .temperature(0.7)
    .topK(50)
    .topP(0.9)
    .minNewTokens(50)
    .maxNewTokens(500)
    .randomSeed(42)
    .repetitionPenalty(1.2)
    .stopSequences(List.of("\n\n", "END", "---"))
    .includeStopSequence(false)
    .truncateInputTokens(2048)
    .decayFactor(1.5)
    .startIndex(10)
    .promptJoiner("\n---\n")
    .logRequests(true)
    .build();

Length Penalty

Control generation length with decay-based penalties.

Length Penalty Configuration:

// Using builder methods
WatsonxGenerationModel model = WatsonxGenerationModel.builder()
    .decayFactor(1.5)    // Penalty strength
    .startIndex(10)       // Start applying penalty at token 10
    .build();

// Length penalty is applied during generation:
// penalty = decayFactor ^ (current_position - startIndex)
// For positions >= startIndex, token scores are divided by penalty

Length Penalty Example:

// Encourage longer responses
WatsonxGenerationModel longModel = WatsonxGenerationModel.builder()
    .decayFactor(1.2)     // Gentle penalty
    .startIndex(100)      // Start penalty after 100 tokens
    .maxNewTokens(500)
    .build();

// Encourage shorter responses
WatsonxGenerationModel shortModel = WatsonxGenerationModel.builder()
    .decayFactor(2.0)     // Strong penalty
    .startIndex(20)       // Start penalty early
    .maxNewTokens(100)
    .build();

Decoding Methods

Control how tokens are selected during generation.

Greedy Decoding:

// Always select most probable token
// Deterministic and focused
WatsonxGenerationModel greedyModel = WatsonxGenerationModel.builder()
    .decodingMethod("greedy")
    .maxNewTokens(200)
    .build();

// Temperature, topK, topP are ignored in greedy mode

Sample Decoding:

// Sample from probability distribution
// More creative and varied
WatsonxGenerationModel sampleModel = WatsonxGenerationModel.builder()
    .decodingMethod("sample")
    .temperature(0.7)      // Controls randomness
    .topK(50)              // Limit to top 50 tokens
    .topP(0.9)             // Nucleus sampling
    .randomSeed(42)        // For reproducibility
    .build();

Dependency Injection with Quarkus

Use Quarkus CDI for automatic model creation and injection.

Configuration:

quarkus.langchain4j.watsonx.base-url=https://us-south.ml.cloud.ibm.com
quarkus.langchain4j.watsonx.api-key=your-api-key
quarkus.langchain4j.watsonx.project-id=your-project-id

# Generation model configuration
quarkus.langchain4j.watsonx.generation-model.model-name=meta-llama/llama-4-maverick-17b-128e-instruct-fp8
quarkus.langchain4j.watsonx.generation-model.decoding-method=sample
quarkus.langchain4j.watsonx.generation-model.temperature=0.7
quarkus.langchain4j.watsonx.generation-model.max-new-tokens=500
quarkus.langchain4j.watsonx.generation-model.min-new-tokens=50
quarkus.langchain4j.watsonx.generation-model.top-k=50
quarkus.langchain4j.watsonx.generation-model.top-p=0.9
quarkus.langchain4j.watsonx.generation-model.repetition-penalty=1.2
quarkus.langchain4j.watsonx.generation-model.random-seed=42
quarkus.langchain4j.watsonx.generation-model.stop-sequences=\n\n,END
quarkus.langchain4j.watsonx.generation-model.truncate-input-tokens=2048
quarkus.langchain4j.watsonx.generation-model.include-stop-sequence=false
quarkus.langchain4j.watsonx.generation-model.prompt-joiner=\n---\n
quarkus.langchain4j.watsonx.generation-model.length-penalty.decay-factor=1.5
quarkus.langchain4j.watsonx.generation-model.length-penalty.start-index=10

Injection:

import jakarta.inject.Inject;
import dev.langchain4j.model.chat.ChatModel;
import dev.langchain4j.model.chat.StreamingChatModel;
import dev.langchain4j.data.message.UserMessage;

@ApplicationScoped
public class GenerationService {
    @Inject
    ChatModel generationModel;  // Injects WatsonxGenerationModel

    @Inject
    StreamingChatModel streamingGenerationModel;  // Injects WatsonxGenerationStreamingModel

    public String generate(String prompt) {
        ChatResponse response = generationModel.chat(UserMessage.from(prompt));
        return response.aiMessage().text();
    }
}

Named Generation Models

Configure multiple generation models with different settings.

Configuration:

# Default generation model
quarkus.langchain4j.watsonx.generation-model.temperature=0.7
quarkus.langchain4j.watsonx.generation-model.max-new-tokens=500

# Creative generation model
quarkus.langchain4j.watsonx.creative.generation-model.model-name=meta-llama/llama-3-70b-instruct
quarkus.langchain4j.watsonx.creative.generation-model.temperature=1.5
quarkus.langchain4j.watsonx.creative.generation-model.max-new-tokens=1000
quarkus.langchain4j.watsonx.creative.generation-model.top-k=100

# Factual generation model
quarkus.langchain4j.watsonx.factual.generation-model.temperature=0.1
quarkus.langchain4j.watsonx.factual.generation-model.decoding-method=greedy
quarkus.langchain4j.watsonx.factual.generation-model.max-new-tokens=200

Injection:

import jakarta.enterprise.inject.Named;

@ApplicationScoped
public class MultiModelService {
    @Inject
    @Named("creative")
    ChatModel creativeModel;

    @Inject
    @Named("factual")
    ChatModel factualModel;

    public String generateCreative(String prompt) {
        return creativeModel.chat(UserMessage.from(prompt)).aiMessage().text();
    }

    public String generateFactual(String query) {
        return factualModel.chat(UserMessage.from(query)).aiMessage().text();
    }
}

Types

Generation Request Parameters

public class WatsonxGenerationRequestParameters extends DefaultChatRequestParameters {
    public static Builder builder();

    // Generation-specific methods
    public String decodingMethod();
    public LengthPenalty lengthPenalty();
    public Integer minNewTokens();
    public Integer randomSeed();
    public Duration timeLimit();
    public Double repetitionPenalty();
    public Integer truncateInputTokens();
    public Boolean includeStopSequence();

    // Override parameters
    public ChatRequestParameters overrideWith(ChatRequestParameters that);
}

See Request Parameters for complete details.

Length Penalty Type

public record LengthPenalty(Double decayFactor, Integer startIndex) {
    // Decay factor: > 1.0
    // Start index: >= 0
}

Text Generation Response

Internal response beans:

public record TextGenerationResponse(
    String modelId,
    List<Result> results
) {
    public record Result(
        String generatedText,
        Integer generatedTokenCount,
        Integer inputTokenCount,
        String stopReason
    ) {}
}

Stop Reasons:

"eos_token": End-of-sequence token reached
"stop_sequence": Stop sequence matched
"max_tokens": Maximum tokens reached
"time_limit": Time limit exceeded

Chat vs Generation Models

When to Use Generation Models

Use generation models when:

You need backward compatibility with legacy Watsonx generation API
You require specific generation parameters (topK, repetitionPenalty, length penalty)
You don't need tool/function calling capabilities
You prefer greedy decoding for deterministic outputs
You need fine-grained control over token sampling

When to Use Chat Models

Use chat models when:

You need tool/function calling capabilities
You want structured JSON outputs with schema validation
You need multi-turn conversation support
You prefer modern chat-based APIs
You want to use frequency and presence penalties

Parameter Comparison

Parameter	Generation Model	Chat Model
Decoding method	greedy, sample	Not exposed
Temperature	Yes (sample only)	Yes
Top-K sampling	Yes (sample only)	No
Top-P sampling	Yes	Yes
Frequency penalty	No	Yes
Presence penalty	No	Yes
Repetition penalty	Yes	No
Length penalty	Yes (decay-based)	No
Min tokens	Yes	No
Max tokens	Yes (maxNewTokens)	Yes (maxTokens)
Stop sequences	Yes (max 6)	Yes (max 4)
Tool calling	No	Yes
JSON schema	No	Yes
Random seed	Yes (randomSeed)	Yes (seed)

Migration from Generation to Chat

// Generation model (legacy)
WatsonxGenerationModel genModel = WatsonxGenerationModel.builder()
    .decodingMethod("sample")
    .temperature(0.7)
    .topK(50)
    .topP(0.9)
    .maxNewTokens(500)
    .repetitionPenalty(1.2)
    .build();

// Equivalent chat model (modern)
WatsonxChatModel chatModel = WatsonxChatModel.builder()
    .temperature(0.7)
    .topP(0.9)
    .maxTokens(500)
    .frequencyPenalty(0.5)  // Approximate repetitionPenalty
    .build();
// Note: topK not available in chat models

Best Practices

Sampling Parameters

// Balanced sampling for general text generation
WatsonxGenerationModel balanced = WatsonxGenerationModel.builder()
    .decodingMethod("sample")
    .temperature(0.7)
    .topK(50)
    .topP(0.9)
    .build();

// Creative/diverse generation
WatsonxGenerationModel creative = WatsonxGenerationModel.builder()
    .decodingMethod("sample")
    .temperature(1.2)
    .topK(100)
    .topP(0.95)
    .build();

// Focused/deterministic generation
WatsonxGenerationModel focused = WatsonxGenerationModel.builder()
    .decodingMethod("greedy")
    .build();

Repetition Control

// Reduce repetition with repetition penalty
WatsonxGenerationModel model = WatsonxGenerationModel.builder()
    .repetitionPenalty(1.3)  // 1.0 = no penalty, 2.0 = maximum penalty
    .build();

// Combine with stop sequences for clean outputs
WatsonxGenerationModel model2 = WatsonxGenerationModel.builder()
    .repetitionPenalty(1.2)
    .stopSequences(List.of("\n\n", "END"))
    .includeStopSequence(false)
    .build();

Token Limits

// Ensure minimum response length
WatsonxGenerationModel minLength = WatsonxGenerationModel.builder()
    .minNewTokens(100)
    .maxNewTokens(500)
    .build();

// Handle long inputs with truncation
WatsonxGenerationModel truncated = WatsonxGenerationModel.builder()
    .truncateInputTokens(2048)  // Truncate from left if input > 2048 tokens
    .maxNewTokens(500)
    .build();

Reproducible Generation

// Same seed + parameters = same output
WatsonxGenerationModel reproducible = WatsonxGenerationModel.builder()
    .decodingMethod("sample")
    .randomSeed(42)
    .temperature(0.7)
    .build();

ChatResponse response1 = reproducible.chat(UserMessage.from("Hello"));
ChatResponse response2 = reproducible.chat(UserMessage.from("Hello"));
// response1 and response2 will be identical

Install with Tessl CLI

npx tessl i tessl/maven-io-quarkiverse-langchain4j--quarkus-langchain4j-watsonx@1.7.0

docs

request-parameters.md

text-extraction.md

tile.json

tessl/maven-io-quarkiverse-langchain4j--quarkus-langchain4j-watsonx