ucp

pkg/cart/mcp/tools.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"log"
 
 	"git.k6n.net/mats/go-cart-actor/pkg/cart"
 	messages "git.k6n.net/mats/go-cart-actor/proto/cart"
@@ -26,6 +27,12 @@ func (s *Server) callTool(req *rpcRequest) *rpcResponse {
 	if err := json.Unmarshal(req.Params, &p); err != nil {
 		return errorResponse(req.ID, codeInvalidParams, "invalid params")
 	}
+
+	// Extract UCP meta from arguments (UCP-Agent profile advertisement).
+	// Per the UCP spec, meta is a sibling key inside arguments:
+	//   "arguments": { "meta": { "ucp-agent": { "profile": "..." } }, ... }
+	args := extractUCPAgentMeta(&p.Arguments)
+
 	var t *tool
 	for i := range s.tools {
 		if s.tools[i].Name == p.Name {
@@ -36,13 +43,48 @@ func (s *Server) callTool(req *rpcRequest) *rpcResponse {
 	if t == nil {
 		return errorResponse(req.ID, codeInvalidParams, "unknown tool: "+p.Name)
 	}
-	out, err := t.invoke(p.Arguments)
+	out, err := t.invoke(args)
 	if err != nil {
 		return result(req.ID, toolError(err))
 	}
 	return result(req.ID, toolText(out))
 }
 
+// extractUCPAgentMeta checks if the JSON arguments contain a "meta" key with
+// a nested "ucp-agent.profile" field. If found, it logs the profile (for
+// observability) and strips the "meta" key before returning the cleaned
+// arguments to the tool handler, so the meta object does not leak into the
+// tool's argument namespace.
+func extractUCPAgentMeta(arguments *json.RawMessage) json.RawMessage {
+	if arguments == nil || len(*arguments) == 0 {
+		return *arguments
+	}
+	var obj map[string]json.RawMessage
+	if err := json.Unmarshal(*arguments, &obj); err != nil {
+		return *arguments
+	}
+	metaRaw, hasMeta := obj["meta"]
+	if !hasMeta {
+		return *arguments
+	}
+	// Try to extract the profile for observability.
+	var meta struct {
+		UCPAgent *struct {
+			Profile string `json:"profile"`
+		} `json:"ucp-agent"`
+	}
+	if err := json.Unmarshal(metaRaw, &meta); err == nil && meta.UCPAgent != nil && meta.UCPAgent.Profile != "" {
+		log.Printf("ucp-agent: profile=%s", meta.UCPAgent.Profile)
+	}
+	// Strip meta from arguments before passing to the tool handler.
+	delete(obj, "meta")
+	cleaned, err := json.Marshal(obj)
+	if err != nil {
+		return *arguments
+	}
+	return cleaned
+}
+
 func (s *Server) buildTools() []tool {
 	return []tool{
 		{

pkg/order/mcp/tools.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"log"
 	"time"
 
 	"git.k6n.net/mats/go-cart-actor/pkg/order"
@@ -27,6 +28,12 @@ func (s *Server) callTool(req *rpcRequest) *rpcResponse {
 	if err := json.Unmarshal(req.Params, &p); err != nil {
 		return errorResponse(req.ID, codeInvalidParams, "invalid params")
 	}
+
+	// Extract UCP meta from arguments (UCP-Agent profile advertisement).
+	// Per the UCP spec, meta is a sibling key inside arguments:
+	//   "arguments": { "meta": { "ucp-agent": { "profile": "..." } }, ... }
+	args := extractUCPAgentMeta(&p.Arguments)
+
 	var t *tool
 	for i := range s.tools {
 		if s.tools[i].Name == p.Name {
@@ -37,13 +44,48 @@ func (s *Server) callTool(req *rpcRequest) *rpcResponse {
 	if t == nil {
 		return errorResponse(req.ID, codeInvalidParams, "unknown tool: "+p.Name)
 	}
-	out, err := t.invoke(p.Arguments)
+	out, err := t.invoke(args)
 	if err != nil {
 		return result(req.ID, toolError(err))
 	}
 	return result(req.ID, toolText(out))
 }
 
+// extractUCPAgentMeta checks if the JSON arguments contain a "meta" key with
+// a nested "ucp-agent.profile" field. If found, it logs the profile (for
+// observability) and strips the "meta" key before returning the cleaned
+// arguments to the tool handler, so the meta object does not leak into the
+// tool's argument namespace.
+func extractUCPAgentMeta(arguments *json.RawMessage) json.RawMessage {
+	if arguments == nil || len(*arguments) == 0 {
+		return *arguments
+	}
+	var obj map[string]json.RawMessage
+	if err := json.Unmarshal(*arguments, &obj); err != nil {
+		return *arguments
+	}
+	metaRaw, hasMeta := obj["meta"]
+	if !hasMeta {
+		return *arguments
+	}
+	// Try to extract the profile for observability.
+	var meta struct {
+		UCPAgent *struct {
+			Profile string `json:"profile"`
+		} `json:"ucp-agent"`
+	}
+	if err := json.Unmarshal(metaRaw, &meta); err == nil && meta.UCPAgent != nil && meta.UCPAgent.Profile != "" {
+		log.Printf("ucp-agent: profile=%s", meta.UCPAgent.Profile)
+	}
+	// Strip meta from arguments before passing to the tool handler.
+	delete(obj, "meta")
+	cleaned, err := json.Marshal(obj)
+	if err != nil {
+		return *arguments
+	}
+	return cleaned
+}
+
 func (s *Server) buildTools() []tool {
 	return []tool{
 		{