Request Parameters

OllamaChatRequestParameters extends the standard LangChain4j chat request parameters with Ollama-specific options for fine-grained control over model behavior.

OllamaChatRequestParameters

Ollama-specific request parameters for chat models.

Class Signature

package dev.langchain4j.model.ollama;

public class OllamaChatRequestParameters extends DefaultChatRequestParameters

Immutability: Immutable after creation

Thread Safety: Thread-safe; can be shared across threads

Nullability: Fields can be null (means use default from previous layer)

Creating an Instance

public static OllamaChatRequestParameters.Builder builder()

Returns a builder for creating OllamaChatRequestParameters instances.

Returns: Fresh builder instance

• Never null
• Not thread-safe

Example:

OllamaChatRequestParameters params = OllamaChatRequestParameters.builder()
    .temperature(0.7)
    .mirostat(2)
    .numCtx(4096)
    .build();

Builder Methods

mirostat

public Builder mirostat(Integer mirostat)

Sets the Mirostat sampling mode for perplexity control.

Parameters:

• mirostat - Mirostat mode
  • Valid values: 0 (disabled), 1 (Mirostat), 2 (Mirostat 2.0)
  • Default: 0
  • Null means use default

Returns: This builder (never null)

Throws:

• IllegalArgumentException at build() - If value not in {0, 1, 2}

Example:

OllamaChatRequestParameters params = OllamaChatRequestParameters.builder()
    .mirostat(2)  // Use Mirostat 2.0
    .build();

numCtx

public Builder numCtx(Integer numCtx)

Sets the context window size in tokens.

Parameters:

• numCtx - Context window size
  • Valid range: > 0
  • Default: Model-specific default
  • Typical values: 2048, 4096, 8192
  • Null means use model default

Returns: This builder (never null)

Throws:

• IllegalArgumentException at build() - If numCtx <= 0

Note: Larger contexts use more memory and are slower

Example:

OllamaChatRequestParameters params = OllamaChatRequestParameters.builder()
    .numCtx(4096)  // 4K context window
    .build();

think

public Builder think(Boolean think)

Controls thinking/reasoning mode for models like DeepSeek R1.

Parameters:

• think - Thinking mode
  • true: LLM thinks and returns thoughts in separate thinking field
  • false: LLM does not think
  • null (default): Reasoning LLMs prepend thoughts with <think> tags

Returns: This builder (never null)

Example:

OllamaChatRequestParameters params = OllamaChatRequestParameters.builder()
    .think(true)  // Enable structured thinking
    .build();

Parameter Reference

Ollama-Specific Parameters

See Also

• Chat Models - Using parameters with chat models
• Language Models - Language model configuration