diff --git a/examples/llms/providers/customChatProvider.ts b/examples/llms/providers/customChatProvider.ts
index e31fb059..9e5ae543 100644
--- a/examples/llms/providers/customChatProvider.ts
+++ b/examples/llms/providers/customChatProvider.ts
@@ -5,6 +5,7 @@ import {
   GenerateOptions,
   LLMCache,
   LLMMeta,
+  StreamGenerateOptions,
 } from "bee-agent-framework/llms/base";
 import { shallowCopy } from "bee-agent-framework/serializer/utils";
 import type { GetRunContext } from "bee-agent-framework/context";
@@ -86,7 +87,7 @@ export class CustomChatLLM extends ChatLLM<CustomChatLLMOutput, CustomGenerateOp
 
   protected async _generate(
     input: BaseMessage[],
-    options: CustomGenerateOptions,
+    options: Partial<CustomGenerateOptions>,
     run: GetRunContext<this>,
   ): Promise<CustomChatLLMOutput> {
     // this method should do non-stream request to the API
@@ -101,7 +102,7 @@ export class CustomChatLLM extends ChatLLM<CustomChatLLMOutput, CustomGenerateOp
 
   protected async *_stream(
     input: BaseMessage[],
-    options: CustomGenerateOptions,
+    options: Partial<StreamGenerateOptions>,
     run: GetRunContext<this>,
   ): AsyncStream<CustomChatLLMOutput, void> {
     // this method should do stream request to the API
diff --git a/examples/llms/providers/customProvider.ts b/examples/llms/providers/customProvider.ts
index a8b5ea0e..7aff13d7 100644
--- a/examples/llms/providers/customProvider.ts
+++ b/examples/llms/providers/customProvider.ts
@@ -86,7 +86,7 @@ export class CustomLLM extends LLM<CustomLLMOutput, CustomGenerateOptions> {
 
   protected async _generate(
     input: LLMInput,
-    options: CustomGenerateOptions,
+    options: Partial<CustomGenerateOptions>,
     run: GetRunContext<this>,
   ): Promise<CustomLLMOutput> {
     // this method should do non-stream request to the API
@@ -101,7 +101,7 @@ export class CustomLLM extends LLM<CustomLLMOutput, CustomGenerateOptions> {
 
   protected async *_stream(
     input: LLMInput,
-    options: CustomGenerateOptions,
+    options: Partial<CustomGenerateOptions>,
     run: GetRunContext<this>,
   ): AsyncStream<CustomLLMOutput, void> {
     // this method should do stream request to the API
diff --git a/src/adapters/bedrock/chat.ts b/src/adapters/bedrock/chat.ts
index 38518215..baddd98e 100644
--- a/src/adapters/bedrock/chat.ts
+++ b/src/adapters/bedrock/chat.ts
@@ -208,7 +208,7 @@ export class BedrockChatLLM extends ChatLLM<ChatBedrockOutput> {
 
   protected async _generate(
     input: BaseMessage[],
-    _options: GenerateOptions | undefined,
+    _options: Partial<GenerateOptions>,
     run: GetRunContext<typeof this>,
   ): Promise<ChatBedrockOutput> {
     const { conversation, systemMessage } = this.convertToConverseMessages(input);
diff --git a/src/adapters/groq/chat.ts b/src/adapters/groq/chat.ts
index 5521cd88..2d43ac46 100644
--- a/src/adapters/groq/chat.ts
+++ b/src/adapters/groq/chat.ts
@@ -209,7 +209,7 @@ export class GroqChatLLM extends ChatLLM<ChatGroqOutput> {
 
   protected async *_stream(
     input: BaseMessage[],
-    options: StreamGenerateOptions,
+    options: Partial<StreamGenerateOptions>,
     run: GetRunContext<typeof this>,
   ): AsyncStream<ChatGroqOutput> {
     for await (const chunk of await this.client.chat.completions.create(
diff --git a/src/adapters/langchain/llms/llm.ts b/src/adapters/langchain/llms/llm.ts
index 45676913..2ee3520b 100644
--- a/src/adapters/langchain/llms/llm.ts
+++ b/src/adapters/langchain/llms/llm.ts
@@ -110,7 +110,7 @@ export class LangChainLLM extends LLM<LangChainLLMOutput> {
 
   protected async _generate(
     input: LLMInput,
-    _options: GenerateOptions | undefined,
+    _options: Partial<GenerateOptions>,
     run: GetRunContext<this>,
   ): Promise<LangChainLLMOutput> {
     const { generations } = await this.lcLLM.generate([input], {
diff --git a/src/adapters/ollama/chat.ts b/src/adapters/ollama/chat.ts
index 61687385..dd4e3395 100644
--- a/src/adapters/ollama/chat.ts
+++ b/src/adapters/ollama/chat.ts
@@ -187,7 +187,7 @@ export class OllamaChatLLM extends ChatLLM<OllamaChatLLMOutput> {
 
   protected async *_stream(
     input: BaseMessage[],
-    options: StreamGenerateOptions,
+    options: Partial<StreamGenerateOptions>,
     run: GetRunContext<typeof this>,
   ): AsyncStream<OllamaChatLLMOutput> {
     for await (const chunk of await this.client.chat({
diff --git a/src/adapters/ollama/llm.ts b/src/adapters/ollama/llm.ts
index c3afb438..3b490ce0 100644
--- a/src/adapters/ollama/llm.ts
+++ b/src/adapters/ollama/llm.ts
@@ -149,7 +149,7 @@ export class OllamaLLM extends LLM<OllamaLLMOutput> {
 
   protected async *_stream(
     input: LLMInput,
-    options: StreamGenerateOptions,
+    options: Partial<StreamGenerateOptions>,
     run: GetRunContext<typeof this>,
   ): AsyncStream<OllamaLLMOutput, void> {
     for await (const chunk of await this.client.generate({
diff --git a/src/adapters/openai/chat.ts b/src/adapters/openai/chat.ts
index 89ba298e..3d9363d7 100644
--- a/src/adapters/openai/chat.ts
+++ b/src/adapters/openai/chat.ts
@@ -224,7 +224,7 @@ export class OpenAIChatLLM extends ChatLLM<OpenAIChatLLMOutput> {
 
   protected async _generate(
     input: BaseMessage[],
-    options: GenerateOptions | undefined,
+    options: Partial<GenerateOptions>,
     run: GetRunContext<typeof this>,
   ): Promise<OpenAIChatLLMOutput> {
     const response = await this.client.chat.completions.create(
diff --git a/src/adapters/vertexai/chat.ts b/src/adapters/vertexai/chat.ts
index ab978800..428fcb75 100644
--- a/src/adapters/vertexai/chat.ts
+++ b/src/adapters/vertexai/chat.ts
@@ -21,6 +21,7 @@ import {
   GenerateOptions,
   LLMCache,
   LLMMeta,
+  StreamGenerateOptions,
 } from "@/llms/base.js";
 import { shallowCopy } from "@/serializer/utils.js";
 import type { GetRunContext } from "@/context.js";
@@ -137,7 +138,7 @@ export class VertexAIChatLLM extends ChatLLM<VertexAIChatLLMOutput> {
 
   protected async *_stream(
     input: BaseMessage[],
-    options: GenerateOptions | undefined,
+    options: Partial<StreamGenerateOptions>,
     run: GetRunContext<this>,
   ): AsyncStream<VertexAIChatLLMOutput, void> {
     const generativeModel = createModel(
diff --git a/src/adapters/vertexai/llm.ts b/src/adapters/vertexai/llm.ts
index 3f8d842a..679be7f0 100644
--- a/src/adapters/vertexai/llm.ts
+++ b/src/adapters/vertexai/llm.ts
@@ -23,6 +23,7 @@ import {
   GenerateOptions,
   LLMCache,
   LLMMeta,
+  StreamGenerateOptions,
 } from "@/llms/base.js";
 import { shallowCopy } from "@/serializer/utils.js";
 import type { GetRunContext } from "@/context.js";
@@ -134,7 +135,7 @@ export class VertexAILLM extends LLM<VertexAILLMOutput> {
 
   protected async *_stream(
     input: LLMInput,
-    options: GenerateOptions | undefined,
+    options: Partial<StreamGenerateOptions>,
     run: GetRunContext<this>,
   ): AsyncStream<VertexAILLMOutput, void> {
     const generativeModel = createModel(
diff --git a/src/llms/base.test.ts b/src/llms/base.test.ts
index 7fcdcabd..1d1bbbae 100644
--- a/src/llms/base.test.ts
+++ b/src/llms/base.test.ts
@@ -16,12 +16,12 @@
 
 import {
   BaseLLMTokenizeOutput,
-  StreamGenerateOptions,
   AsyncStream,
   BaseLLMOutput,
   GenerateOptions,
   BaseLLM,
   BaseLLMEvents,
+  StreamGenerateOptions,
 } from "./base.js";
 import { Emitter } from "@/emitter/emitter.js";
 import { UnconstrainedCache } from "@/cache/unconstrainedCache.js";
@@ -74,7 +74,7 @@ describe("BaseLLM", () => {
 
     protected async _generate(
       input: string,
-      options: GenerateOptions | undefined,
+      options: Partial<GenerateOptions>,
     ): Promise<DummyOutput> {
       options?.signal?.throwIfAborted();
       await setTimeout(200);
@@ -87,7 +87,7 @@ describe("BaseLLM", () => {
 
     protected async *_stream(
       input: string,
-      options: StreamGenerateOptions | undefined,
+      options: Partial<StreamGenerateOptions>,
     ): AsyncStream<DummyOutput, void> {
       for (const chunk of input.split(",")) {
         if (options?.signal?.aborted) {
diff --git a/src/llms/base.ts b/src/llms/base.ts
index 4561e122..f4c1322c 100644
--- a/src/llms/base.ts
+++ b/src/llms/base.ts
@@ -144,7 +144,10 @@ export abstract class BaseLLM<
 
   abstract tokenize(input: TInput): Promise<BaseLLMTokenizeOutput>;
 
-  generate(input: TInput, options?: TGenerateOptions) {
+  generate(input: TInput, options: Partial<TGenerateOptions> = {}) {
+    input = shallowCopy(input);
+    options = shallowCopy(options);
+
     return RunContext.enter(
       this,
       { params: [input, options] as const, signal: options?.signal },
@@ -187,8 +190,7 @@ export abstract class BaseLLM<
 
           const result: TOutput =
             cacheEntry?.value?.at(0) ||
-            // @ts-expect-error types
-            (await pRetry(() => this._generate(input, options ?? {}, run), {
+            (await pRetry(() => this._generate(input, options, run), {
               retries: this.executionOptions.maxRetries || 0,
               ...options,
               signal: run.signal,
@@ -211,7 +213,10 @@ export abstract class BaseLLM<
     ).middleware(INSTRUMENTATION_ENABLED ? createTelemetryMiddleware() : doNothing());
   }
 
-  async *stream(input: TInput, options?: StreamGenerateOptions): AsyncStream<TOutput> {
+  async *stream(input: TInput, options: Partial<StreamGenerateOptions> = {}): AsyncStream<TOutput> {
+    input = shallowCopy(input);
+    options = shallowCopy(options);
+
     return yield* emitterToGenerator(async ({ emit }) => {
       return RunContext.enter(
         this,
@@ -232,13 +237,13 @@ export abstract class BaseLLM<
 
   protected abstract _generate(
     input: TInput,
-    options: TGenerateOptions,
+    options: Partial<TGenerateOptions>,
     run: GetRunContext<typeof this>,
   ): Promise<TOutput>;
 
   protected abstract _stream(
     input: TInput,
-    options: StreamGenerateOptions,
+    options: Partial<StreamGenerateOptions>,
     run: GetRunContext<typeof this>,
   ): AsyncStream<TOutput, void>;
 
@@ -279,7 +284,7 @@ export abstract class BaseLLM<
 
   protected async createCacheAccessor(
     input: TInput,
-    options: GenerateOptions | StreamGenerateOptions | undefined,
+    options: Partial<GenerateOptions> | Partial<StreamGenerateOptions>,
     ...extra: any[]
   ) {
     const key = ObjectHashKeyFn(input, omit(options ?? {}, ["signal"]), ...extra);