feat: auto-save config after claim, auto-heartbeat in MCP serve

- claim: save agent_id, keypair path, and server URL to
  ~/.peerclaw/config.yaml after successful registration
- mcp serve: read agent_id from config and start background heartbeat
  goroutine (every 3 minutes) to keep agent online automatically
- config: add agent_id and keypair fields, display in config show

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: gcmsg

internal/cmd/claim.go

@@ -74,16 +74,27 @@ func runAgentClaim(args []string, serverURL string) int {
 		return 1
 	}
 
+	// Save agent ID, keypair path, and server to config for future use.
+	cfg, _ := loadCLIConfig()
+	cfg.AgentID = card.ID
+	cfg.Keypair = *keypairPath
+	if cfg.Server == "" || cfg.Server == defaultServer {
+		cfg.Server = serverURL
+	}
+	if err := saveCLIConfig(cfg); err != nil {
+		fmt.Fprintf(os.Stderr, "Warning: could not save config: %v\n", err)
+	}
+
 	fmt.Fprintf(os.Stderr, "\nAgent registered successfully!\n")
 	fmt.Fprintf(os.Stderr, "  ID:         %s\n", card.ID)
 	fmt.Fprintf(os.Stderr, "  Name:       %s\n", card.Name)
 	fmt.Fprintf(os.Stderr, "  Public Key: %s\n", kp.PublicKeyString())
-	fmt.Fprintf(os.Stderr, "  Keypair:    %s\n\n", *keypairPath)
+	fmt.Fprintf(os.Stderr, "  Keypair:    %s\n", *keypairPath)
+	fmt.Fprintf(os.Stderr, "  Config:     %s\n\n", configPath())
 	fmt.Fprintf(os.Stderr, "Next steps:\n")
-	fmt.Fprintf(os.Stderr, "  peerclaw agent get %s                        # verify registration\n", card.ID)
-	fmt.Fprintf(os.Stderr, "  peerclaw agent heartbeat %s --status active  # stay discoverable\n", card.ID)
-	fmt.Fprintf(os.Stderr, "  peerclaw invoke <agent-id> --message \"Hello\"   # talk to other agents\n")
-	fmt.Fprintf(os.Stderr, "  peerclaw mcp serve                             # run as MCP tool server\n\n")
+	fmt.Fprintf(os.Stderr, "  peerclaw agent get %s          # verify registration\n", card.ID)
+	fmt.Fprintf(os.Stderr, "  peerclaw mcp serve                       # run as MCP tool server (auto-heartbeat)\n")
+	fmt.Fprintf(os.Stderr, "  peerclaw invoke <agent-id> --message \"Hello\"  # talk to other agents\n\n")
 	fmt.Fprintf(os.Stderr, "Keep %s safe — it proves your agent's identity.\n", *keypairPath)
 	fmt.Fprintf(os.Stderr, "Docs: https://github.com/peerclaw/peerclaw/blob/main/docs/GUIDE.md\n")
 

internal/cmd/config.go

@@ -11,7 +11,9 @@ import (
 
 // CLIConfig holds CLI configuration stored in ~/.peerclaw/config.yaml.
 type CLIConfig struct {
-	Server string `yaml:"server"`
+	Server  string `yaml:"server"`
+	AgentID string `yaml:"agent_id,omitempty"`
+	Keypair string `yaml:"keypair,omitempty"`
 }
 
 func configPath() string {
@@ -81,7 +83,13 @@ func runConfigShow() int {
 		return 1
 	}
 	fmt.Printf("Config file: %s\n", configPath())
-	fmt.Printf("Server: %s\n", cfg.Server)
+	fmt.Printf("Server:      %s\n", cfg.Server)
+	if cfg.AgentID != "" {
+		fmt.Printf("Agent ID:    %s\n", cfg.AgentID)
+	}
+	if cfg.Keypair != "" {
+		fmt.Printf("Keypair:     %s\n", cfg.Keypair)
+	}
 	return 0
 }
 

internal/cmd/mcp.go

@@ -8,9 +8,11 @@ import (
 	"net/http"
 	"os"
 	"os/signal"
+	"time"
 
 	"github.com/modelcontextprotocol/go-sdk/mcp"
 	"github.com/peerclaw/peerclaw-agent/tools"
+	"github.com/peerclaw/peerclaw-cli/internal/client"
 	"github.com/peerclaw/peerclaw-core/agentcard"
 )
 
@@ -82,6 +84,13 @@ func runMCPServe(args []string, serverURL string) int {
 	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
 	defer cancel()
 
+	// Start auto-heartbeat if agent_id is configured.
+	cfg, _ := loadCLIConfig()
+	if cfg != nil && cfg.AgentID != "" {
+		go runAutoHeartbeat(ctx, serverURL, cfg.AgentID)
+		fmt.Fprintf(os.Stderr, "Auto-heartbeat enabled for agent %s\n", cfg.AgentID)
+	}
+
 	if transport == "stdio" {
 		if err := server.Run(ctx, &mcp.StdioTransport{}); err != nil {
 			if ctx.Err() == nil {
@@ -205,6 +214,25 @@ func registerDirectoryResource(server *mcp.Server, apiClient *tools.APIClient) {
 	})
 }
 
+// runAutoHeartbeat sends periodic heartbeats to keep the agent online.
+func runAutoHeartbeat(ctx context.Context, serverURL, agentID string) {
+	c := client.New(serverURL)
+	ticker := time.NewTicker(3 * time.Minute)
+	defer ticker.Stop()
+
+	// Send initial heartbeat immediately.
+	c.Heartbeat(ctx, agentID, client.HeartbeatRequest{Status: "online"})
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			c.Heartbeat(ctx, agentID, client.HeartbeatRequest{Status: "online"})
+		}
+	}
+}
+
 func printMCPUsage() {
 	fmt.Fprintf(os.Stderr, `Usage: peerclaw mcp <command> [options]