Fix tool call return type to parse as JSON before returning (#66)

Author: peteski22

internal/api/servers.go

@@ -2,6 +2,7 @@ package api
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"net/http"
 	"slices"
@@ -162,8 +163,16 @@ func handleServerToolCall(accessor contracts.MCPClientAccessor, server string, t
 		return nil, fmt.Errorf("%w: %s/%s: %v", errors.ErrToolCallFailedUnknown, server, tool, extractMessage(result.Content))
 	}
 
+	// Parse the response content of the tool, ensure we can translate the message as JSON.
+	msg := extractMessage(result.Content)
+	var respData map[string]any
+	err = json.Unmarshal([]byte(msg), &respData)
+	if err != nil {
+		return nil, fmt.Errorf("%w: %s/%s: error parsing response: %s: %w", errors.ErrToolCallFailedUnknown, server, tool, msg, err)
+	}
+
 	resp := &ToolCallResponse{}
-	resp.Body = extractMessage(result.Content)
+	resp.Body = respData
 
 	return resp, nil
 }

internal/api/tools.go

@@ -16,7 +16,7 @@ type ToolsResponse struct {
 
 // ToolCallResponse represents the wrapped API response for calling a tool.
 type ToolCallResponse struct {
-	Body string
+	Body map[string]any
 }
 
 // Tool represents a callable tool, following the MCP spec.

internal/runtime/server.go

@@ -54,7 +54,7 @@ func AggregateConfigs(
 }
 
 func (s *Server) Environ() []string {
-	baseEnvs := os.Environ()
+	baseEnvs := os.Environ() // TODO: Only 'add' required/configured env vars for this server's binary.
 	overrideEnvs := make([]string, 0, len(s.Env))
 	for k, v := range s.Env {
 		overrideEnvs = append(overrideEnvs, fmt.Sprintf("%s=%s", k, v))