diff --git a/src/AgentNet.Tests/PollyInProcessTests.fs b/src/AgentNet.Tests/PollyInProcessTests.fs
index 0ededb7..87acd87 100644
--- a/src/AgentNet.Tests/PollyInProcessTests.fs
+++ b/src/AgentNet.Tests/PollyInProcessTests.fs
@@ -131,7 +131,7 @@ let ``Policy forwards CancellationToken through TypedAgent to ChatAgent``() =
     // Arrange: A ChatAgent whose Chat function observes the cancellation token
     let mutable tokenWasCancelled = false
 
-    let config = { Name = Some "TestAgent"; Instructions = "test"; Tools = [] }
+    let config = { Name = Some "TestAgent"; Instructions = "test"; Tools = []; ChatOptions = None }
 
     let chatFn msg ct = task {
         try
diff --git a/src/AgentNet/AgentFramework.fs b/src/AgentNet/AgentFramework.fs
index d1d4b80..5a66289 100644
--- a/src/AgentNet/AgentFramework.fs
+++ b/src/AgentNet/AgentFramework.fs
@@ -25,6 +25,39 @@ module MAF =
         // The explicit annotation ensures correct overload resolution
         AIFunctionFactory.Create(method = tool.MethodInfo, target = null, options = options)
 
+    /// Wraps an IChatClient to merge default ChatOptions into every call.
+    /// Defaults are the base; per-call options override where present.
+    let private withDefaultOptions (defaults: ChatOptions) (inner: IChatClient) =
+        let mergeOptions (callOptions: ChatOptions) =
+            let merged = defaults.Clone()
+            if callOptions <> null then
+                if callOptions.Temperature.HasValue then merged.Temperature <- callOptions.Temperature
+                if callOptions.TopP.HasValue then merged.TopP <- callOptions.TopP
+                if callOptions.TopK.HasValue then merged.TopK <- callOptions.TopK
+                if callOptions.MaxOutputTokens.HasValue then merged.MaxOutputTokens <- callOptions.MaxOutputTokens
+                if callOptions.FrequencyPenalty.HasValue then merged.FrequencyPenalty <- callOptions.FrequencyPenalty
+                if callOptions.PresencePenalty.HasValue then merged.PresencePenalty <- callOptions.PresencePenalty
+                if callOptions.Seed.HasValue then merged.Seed <- callOptions.Seed
+                if callOptions.ModelId <> null then merged.ModelId <- callOptions.ModelId
+                if callOptions.ResponseFormat <> null then merged.ResponseFormat <- callOptions.ResponseFormat
+                if callOptions.StopSequences <> null && callOptions.StopSequences.Count > 0 then
+                    merged.StopSequences <- ResizeArray(callOptions.StopSequences)
+                for tool in callOptions.Tools do merged.Tools.Add(tool)
+                if callOptions.AdditionalProperties <> null then
+                    if merged.AdditionalProperties = null then
+                        merged.AdditionalProperties <- AdditionalPropertiesDictionary()
+                    for kvp in callOptions.AdditionalProperties do
+                        merged.AdditionalProperties.[kvp.Key] <- kvp.Value
+            merged
+        { new IChatClient with
+            member _.GetResponseAsync(messages, options, ct) =
+                inner.GetResponseAsync(messages, mergeOptions options, ct)
+            member _.GetStreamingResponseAsync(messages, options, ct) =
+                inner.GetStreamingResponseAsync(messages, mergeOptions options, ct)
+            member _.GetService(serviceType, serviceKey) =
+                inner.GetService(serviceType, serviceKey)
+            member _.Dispose() = () }
+
     /// Creates a ChatClientAgent from an AgentNet ChatAgent config
     let createAgent (chatClient: IChatClient) (config: ChatAgentConfig) : AIAgent =
         // Convert tools to AIFunctions and cast to AITool
@@ -34,9 +67,14 @@ module MAF =
             |> ResizeArray
             :> IList<AITool>
 
+        let client =
+            match config.ChatOptions with
+            | Some opts -> withDefaultOptions opts chatClient
+            | None -> chatClient
+
         // Create the agent using the constructor with named parameters
         ChatClientAgent(
-            chatClient,
+            client,
             name = (config.Name |> Option.defaultValue "Agent"),
             instructions = config.Instructions,
             tools = tools) :> AIAgent
diff --git a/src/AgentNet/ChatAgent.fs b/src/AgentNet/ChatAgent.fs
index 152f299..82c7187 100644
--- a/src/AgentNet/ChatAgent.fs
+++ b/src/AgentNet/ChatAgent.fs
@@ -3,12 +3,14 @@ namespace AgentNet
 open System.Collections.Generic
 open System.Threading
 open System.Threading.Tasks
+open Microsoft.Extensions.AI
 
 /// Configuration for a chat agent
 type ChatAgentConfig = {
     Name: string option
     Instructions: string
     Tools: ToolDef list
+    ChatOptions: ChatOptions option
 }
 
 /// Role of a participant in a chat conversation
@@ -75,7 +77,7 @@ type ChatAgent with
 
     /// Creates an agent config with the given instructions
     static member create (instructions: string) : ChatAgentConfig =
-        { Name = None; Instructions = instructions; Tools = [] }
+        { Name = None; Instructions = instructions; Tools = []; ChatOptions = None }
 
     /// Sets the agent's name
     static member withName (name: string) (config: ChatAgentConfig) : ChatAgentConfig =
@@ -88,3 +90,7 @@ type ChatAgent with
     /// Adds a list of tools to the agent
     static member withTools (tools: ToolDef list) (config: ChatAgentConfig) : ChatAgentConfig =
         { config with Tools = config.Tools @ tools }
+
+    /// Sets ChatOptions (temperature, top-p, model, etc.) for the agent
+    static member withChatOptions (options: ChatOptions) (config: ChatAgentConfig) : ChatAgentConfig =
+        { config with ChatOptions = Some options }