Allow extra headers for specific conversations too

This commit adds support for setting extra HTTP headers for all
requests issued as part of a specific conversation. These headers
will be sent in addition to any extra headers defined for the
backend itself, if any, and will take precedence over them.

The bedrock implementation does not support extra headers at all
at this point.

libaiac/bedrock/chat.go

@@ -120,3 +120,6 @@ func (conv *Conversation) Messages() []types.Message {
 	}
 	return msgs
 }
+
+// AddHeader is a noop for the bedrock implementation
+func (conv *Conversation) AddHeader(_ string, _ string) {}

libaiac/ollama/chat.go

@@ -11,9 +11,10 @@ import (
 // Conversation is a struct used to converse with an Ollama chat model. It
 // maintains all messages sent/received in order to maintain context.
 type Conversation struct {
-	backend  *Ollama
-	model    string
-	messages []types.Message
+	backend      *Ollama
+	model        string
+	messages     []types.Message
+	extraHeaders map[string]string
 }
 
 type chatResponse struct {
@@ -55,7 +56,7 @@ func (conv *Conversation) Send(ctx context.Context, prompt string) (
 		Content: prompt,
 	})
 
-	err = conv.backend.NewRequest("POST", "/chat").
+	req := conv.backend.NewRequest("POST", "/chat").
 		JSONBody(map[string]interface{}{
 			"model":    conv.model,
 			"messages": conv.messages,
@@ -64,8 +65,13 @@ func (conv *Conversation) Send(ctx context.Context, prompt string) (
 			},
 			"stream": false,
 		}).
-		Into(&answer).
-		RunContext(ctx)
+		Into(&answer)
+
+	for key, val := range conv.extraHeaders {
+		req.Header(key, val)
+	}
+
+	err = req.RunContext(ctx)
 	if err != nil {
 		return res, fmt.Errorf("failed sending prompt: %w", err)
 	}
@@ -92,3 +98,14 @@ func (conv *Conversation) Send(ctx context.Context, prompt string) (
 func (conv *Conversation) Messages() []types.Message {
 	return conv.messages
 }
+
+// AddHeader adds an extra HTTP header that will be added to every HTTP
+// request issued as part of this conversation. Any headers added will be in
+// addition to any extra headers defined for the backend itself, and will
+// take precedence over them.
+func (conv *Conversation) AddHeader(key, val string) {
+	if conv.extraHeaders == nil {
+		conv.extraHeaders = make(map[string]string)
+	}
+	conv.extraHeaders[key] = val
+}

libaiac/openai/chat.go

@@ -12,9 +12,10 @@ import (
 // maintains all messages sent/received in order to maintain context just like
 // using ChatGPT.
 type Conversation struct {
-	backend  *OpenAI
-	model    string
-	messages []types.Message
+	backend      *OpenAI
+	model        string
+	messages     []types.Message
+	extraHeaders map[string]string
 }
 
 type chatResponse struct {
@@ -67,15 +68,20 @@ func (conv *Conversation) Send(ctx context.Context, prompt string) (
 		apiVersion = fmt.Sprintf("?api-version=%s", conv.backend.apiVersion)
 	}
 
-	err = conv.backend.
+	req := conv.backend.
 		NewRequest("POST", fmt.Sprintf("/chat/completions%s", apiVersion)).
 		JSONBody(map[string]interface{}{
 			"model":       conv.model,
 			"messages":    conv.messages,
 			"temperature": 0.2,
 		}).
-		Into(&answer).
-		RunContext(ctx)
+		Into(&answer)
+
+	for key, val := range conv.extraHeaders {
+		req.Header(key, val)
+	}
+
+	err = req.RunContext(ctx)
 	if err != nil {
 		return res, fmt.Errorf("failed sending prompt: %w", err)
 	}
@@ -104,3 +110,14 @@ func (conv *Conversation) Send(ctx context.Context, prompt string) (
 func (conv *Conversation) Messages() []types.Message {
 	return conv.messages
 }
+
+// AddHeader adds an extra HTTP header that will be added to every HTTP
+// request issued as part of this conversation. Any headers added will be in
+// addition to any extra headers defined for the backend itself, and will
+// take precedence over them.
+func (conv *Conversation) AddHeader(key, val string) {
+	if conv.extraHeaders == nil {
+		conv.extraHeaders = make(map[string]string)
+	}
+	conv.extraHeaders[key] = val
+}

libaiac/types/interfaces.go

@@ -24,6 +24,13 @@ type Conversation interface {
 	Send(context.Context, string) (Response, error)
 
 	// Messages returns all the messages that have been exchanged between the
-	// user and the assistant up to this point
+	// user and the assistant up to this point.
 	Messages() []Message
+
+	// AddHeader adds an extra HTTP header that will be added to every HTTP
+	// request issued as part of this conversation. Any headers added will be in
+	// addition to any extra headers defined for the backend itself, and will
+	// take precedence over them. Not all providers may support this
+	// (specifically, bedrock doesn't).
+	AddHeader(string, string)
 }