diff --git a/e2e_test.go b/e2e_test.go
index 02d0bad..a689e9b 100644
--- a/e2e_test.go
+++ b/e2e_test.go
@@ -13,7 +13,7 @@ import (
 
 	"git.daviestechlabs.io/daviestechlabs/handler-base/clients"
 	"git.daviestechlabs.io/daviestechlabs/handler-base/messages"
-	"github.com/vmihailenco/msgpack/v5"
+	"google.golang.org/protobuf/proto"
 )
 
 // ────────────────────────────────────────────────────────────────────────────
@@ -167,33 +167,33 @@ func TestChatPipeline_LLMTimeout(t *testing.T) {
 }
 
 func TestChatPipeline_TypedDecoding(t *testing.T) {
-	// Verify typed struct decoding from msgpack (same path as OnTypedMessage).
-	raw := map[string]any{
-		"request_id":       "req-e2e-001",
-		"user_id":          "user-1",
-		"message":          "hello",
-		"premium":          true,
-		"enable_rag":       false,
-		"enable_streaming": false,
-		"system_prompt":    "Be brief.",
+	// Verify typed struct decoding from proto (same path as OnTypedMessage).
+	original := &messages.ChatRequest{
+		RequestId:      "req-e2e-001",
+		UserId:         "user-1",
+		Message:        "hello",
+		Premium:        true,
+		EnableRag:      false,
+		EnableStreaming: false,
+		SystemPrompt:   "Be brief.",
 	}
-	data, _ := msgpack.Marshal(raw)
+	data, _ := proto.Marshal(original)
 
 	var req messages.ChatRequest
-	if err := msgpack.Unmarshal(data, &req); err != nil {
+	if err := proto.Unmarshal(data, &req); err != nil {
 		t.Fatal(err)
 	}
 
-	if req.RequestID != "req-e2e-001" {
-		t.Errorf("RequestID = %q", req.RequestID)
+	if req.RequestId != "req-e2e-001" {
+		t.Errorf("RequestID = %q", req.RequestId)
 	}
-	if req.UserID != "user-1" {
-		t.Errorf("UserID = %q", req.UserID)
+	if req.UserId != "user-1" {
+		t.Errorf("UserID = %q", req.UserId)
 	}
-	if req.EffectiveQuery() != "hello" {
-		t.Errorf("query = %q", req.EffectiveQuery())
+	if messages.EffectiveQuery(&req) != "hello" {
+		t.Errorf("query = %q", messages.EffectiveQuery(&req))
 	}
-	if req.EnableRAG {
+	if req.EnableRag {
 		t.Error("EnableRAG should be false")
 	}
 	if req.SystemPrompt != "Be brief." {
diff --git a/go.mod b/go.mod
index 5c8828c..0d414b7 100644
--- a/go.mod
+++ b/go.mod
@@ -3,9 +3,9 @@ module git.daviestechlabs.io/daviestechlabs/chat-handler
 go 1.25.1
 
 require (
-	git.daviestechlabs.io/daviestechlabs/handler-base v0.1.5
+	git.daviestechlabs.io/daviestechlabs/handler-base v1.0.0
 	github.com/nats-io/nats.go v1.48.0
-	github.com/vmihailenco/msgpack/v5 v5.4.1
+	google.golang.org/protobuf v1.36.11
 )
 
 require (
@@ -19,7 +19,6 @@ require (
 	github.com/klauspost/compress v1.18.0 // indirect
 	github.com/nats-io/nkeys v0.4.11 // indirect
 	github.com/nats-io/nuid v1.0.1 // indirect
-	github.com/vmihailenco/tagparser/v2 v2.0.0 // indirect
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
 	go.opentelemetry.io/otel v1.40.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.40.0 // indirect
@@ -37,5 +36,4 @@ require (
 	google.golang.org/genproto/googleapis/api v0.0.0-20260128011058-8636f8732409 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20260128011058-8636f8732409 // indirect
 	google.golang.org/grpc v1.78.0 // indirect
-	google.golang.org/protobuf v1.36.11 // indirect
 )
diff --git a/go.sum b/go.sum
index efceef0..5d7dfc1 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,5 @@
-git.daviestechlabs.io/daviestechlabs/handler-base v0.1.5 h1:DqYZpeluTXh5QKqdVFgN8YIMh4Ycqzw5E9+5FTNDFCA=
-git.daviestechlabs.io/daviestechlabs/handler-base v0.1.5/go.mod h1:M3HgvUDWnRn7cX3BE8l+HvoCUYtmRr5OoumB+hnRHoE=
+git.daviestechlabs.io/daviestechlabs/handler-base v1.0.0 h1:pB3ehOKaDYQfbyRBKQXrB9curqSFteLrDveoElRKnBY=
+git.daviestechlabs.io/daviestechlabs/handler-base v1.0.0/go.mod h1:zocOHFt8yY3cW4+Xi37sNr5Tw7KcjGFSZqgWYxPWyqA=
 github.com/cenkalti/backoff/v5 v5.0.3 h1:ZN+IMa753KfX5hd8vVaMixjnqRZ3y8CuJKRKj1xcsSM=
 github.com/cenkalti/backoff/v5 v5.0.3/go.mod h1:rkhZdG3JZukswDf7f0cwqPNk4K0sa+F97BxZthm/crw=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
@@ -33,10 +33,6 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
-github.com/vmihailenco/msgpack/v5 v5.4.1 h1:cQriyiUvjTwOHg8QZaPihLWeRAAVoCpE00IUPn0Bjt8=
-github.com/vmihailenco/msgpack/v5 v5.4.1/go.mod h1:GaZTsDaehaPpQVyxrf5mtQlH+pc21PIudVV/E3rRQok=
-github.com/vmihailenco/tagparser/v2 v2.0.0 h1:y09buUbR+b5aycVFQs/g70pqKVZNBmxwAhO7/IwNM9g=
-github.com/vmihailenco/tagparser/v2 v2.0.0/go.mod h1:Wri+At7QHww0WTrCBeu4J6bNtoV6mEfg5OIWRZA9qds=
 go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
 go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
 go.opentelemetry.io/otel v1.40.0 h1:oA5YeOcpRTXq6NN7frwmwFR0Cn3RhTVZvXsP4duvCms=
diff --git a/main.go b/main.go
index cd1b106..6227842 100644
--- a/main.go
+++ b/main.go
@@ -16,6 +16,7 @@ import (
 	"git.daviestechlabs.io/daviestechlabs/handler-base/handler"
 	"git.daviestechlabs.io/daviestechlabs/handler-base/messages"
 	"git.daviestechlabs.io/daviestechlabs/handler-base/natsutil"
+	"google.golang.org/protobuf/proto"
 )
 
 func main() {
@@ -45,23 +46,23 @@ func main() {
 
 	h := handler.New("ai.chat.user.*.message", cfg)
 
-	h.OnTypedMessage(func(ctx context.Context, msg *nats.Msg) (any, error) {
-		req, err := natsutil.Decode[messages.ChatRequest](msg.Data)
-		if err != nil {
+	h.OnTypedMessage(func(ctx context.Context, msg *nats.Msg) (proto.Message, error) {
+		var req messages.ChatRequest
+		if err := natsutil.Decode(msg.Data, &req); err != nil {
 			slog.Error("decode failed", "error", err)
 			return &messages.ErrorResponse{Error: true, Message: err.Error(), Type: "DecodeError"}, nil
 		}
 
-		query := req.EffectiveQuery()
-		requestID := req.RequestID
+		query := messages.EffectiveQuery(&req)
+		requestID := req.RequestId
 		if requestID == "" {
 			requestID = "unknown"
 		}
-		userID := req.UserID
+		userID := req.UserId
 		if userID == "" {
 			userID = "unknown"
 		}
-		enableRAG := req.EnableRAG
+		enableRAG := req.EnableRag
 		if !enableRAG && req.Premium {
 			enableRAG = true
 		}
@@ -71,13 +72,13 @@ func main() {
 		}
 		topK := req.TopK
 		if topK == 0 {
-			topK = ragTopK
+			topK = int32(ragTopK)
 		}
 		collection := req.Collection
 		if collection == "" {
 			collection = ragCollection
 		}
-		reqEnableTTS := req.EnableTTS || enableTTS
+		reqEnableTTS := req.EnableTts || enableTTS
 		systemPrompt := req.SystemPrompt
 		responseSubject := req.ResponseSubject
 		if responseSubject == "" {
@@ -159,18 +160,19 @@ func main() {
 
 		// 5. Generate LLM response (streaming when requested)
 		var responseText string
+		var err error
 		if req.EnableStreaming {
 			streamSubject := fmt.Sprintf("ai.chat.response.stream.%s", requestID)
 			responseText, err = llm.StreamGenerate(ctx, query, contextText, systemPrompt, func(token string) {
 				_ = h.NATS.Publish(streamSubject, &messages.ChatStreamChunk{
-					RequestID: requestID,
+					RequestId: requestID,
 					Type:      "chunk",
 					Content:   token,
 					Timestamp: messages.Timestamp(),
 				})
 			})
 			_ = h.NATS.Publish(streamSubject, &messages.ChatStreamChunk{
-				RequestID: requestID,
+				RequestId: requestID,
 				Type:      "done",
 				Done:      true,
 				Timestamp: messages.Timestamp(),
@@ -181,7 +183,7 @@ func main() {
 		if err != nil {
 			slog.Error("LLM generation failed", "error", err)
 			return &messages.ChatResponse{
-				UserID:  userID,
+				UserId:  userID,
 				Success: false,
 				Error:   err.Error(),
 			}, nil
@@ -199,15 +201,15 @@ func main() {
 		}
 
 		result := &messages.ChatResponse{
-			UserID:       userID,
+			UserId:       userID,
 			Response:     responseText,
 			ResponseText: responseText,
-			UsedRAG:      usedRAG,
+			UsedRag:      usedRAG,
 			Success:      true,
 			Audio:        audio,
 		}
 		if includeSources {
-			result.RAGSources = ragSources
+			result.RagSources = ragSources
 		}
 
 		// Publish to the response subject the frontend is waiting on
diff --git a/main_test.go b/main_test.go
index d87d4c5..bda9d6c 100644
--- a/main_test.go
+++ b/main_test.go
@@ -5,28 +5,31 @@ import (
 	"testing"
 
 	"git.daviestechlabs.io/daviestechlabs/handler-base/messages"
-	"github.com/vmihailenco/msgpack/v5"
+	"google.golang.org/protobuf/proto"
 )
 
 func TestChatRequestDecode(t *testing.T) {
-	// Verify a msgpack-encoded map decodes cleanly into typed struct.
-	raw := map[string]any{
-		"request_id": "req-1",
-		"user_id":    "user-1",
-		"message":    "hello",
-		"premium":    true,
-		"top_k":      10,
+	// Verify a proto-encoded struct round-trips cleanly.
+	original := &messages.ChatRequest{
+		RequestId: "req-1",
+		UserId:    "user-1",
+		Message:   "hello",
+		Premium:   true,
+		TopK:      10,
 	}
-	data, _ := msgpack.Marshal(raw)
-	var req messages.ChatRequest
-	if err := msgpack.Unmarshal(data, &req); err != nil {
+	data, err := proto.Marshal(original)
+	if err != nil {
 		t.Fatal(err)
 	}
-	if req.RequestID != "req-1" {
-		t.Errorf("RequestID = %q", req.RequestID)
+	var req messages.ChatRequest
+	if err := proto.Unmarshal(data, &req); err != nil {
+		t.Fatal(err)
 	}
-	if req.EffectiveQuery() != "hello" {
-		t.Errorf("EffectiveQuery = %q", req.EffectiveQuery())
+	if req.RequestId != "req-1" {
+		t.Errorf("RequestID = %q", req.RequestId)
+	}
+	if messages.EffectiveQuery(&req) != "hello" {
+		t.Errorf("EffectiveQuery = %q", messages.EffectiveQuery(&req))
 	}
 	if !req.Premium {
 		t.Error("Premium should be true")
@@ -38,20 +41,20 @@ func TestChatRequestDecode(t *testing.T) {
 
 func TestChatResponseRoundtrip(t *testing.T) {
 	resp := &messages.ChatResponse{
-		UserID:   "user-1",
+		UserId:   "user-1",
 		Response: "answer",
 		Success:  true,
 		Audio:    []byte{0x01, 0x02, 0x03},
 	}
-	data, err := msgpack.Marshal(resp)
+	data, err := proto.Marshal(resp)
 	if err != nil {
 		t.Fatal(err)
 	}
 	var decoded messages.ChatResponse
-	if err := msgpack.Unmarshal(data, &decoded); err != nil {
+	if err := proto.Unmarshal(data, &decoded); err != nil {
 		t.Fatal(err)
 	}
-	if decoded.UserID != "user-1" || !decoded.Success {
+	if decoded.UserId != "user-1" || !decoded.Success {
 		t.Errorf("decoded = %+v", decoded)
 	}
 	if len(decoded.Audio) != 3 {