feat: add agentic_watch tool with MCP progress notifications

Watches running/queued agent workspaces until all complete.
Sends progress notifications via MCP protocol as each agent finishes.
Returns summary with completed/failed counts and PR URLs.

Co-Authored-By: Virgil <virgil@lethean.io>

pkg/agentic/prep.go

@@ -91,6 +91,7 @@ func (s *PrepSubsystem) RegisterTools(server *mcp.Server) {
 	}, s.scan)
 
 	s.registerPlanTools(server)
+	s.registerWatchTool(server)
 }
 
 // Shutdown implements mcp.SubsystemWithShutdown.

pkg/agentic/watch.go

@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: EUPL-1.2
+
+package agentic
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"time"
+
+	coreerr "forge.lthn.ai/core/go-log"
+	"github.com/modelcontextprotocol/go-sdk/mcp"
+)
+
+// WatchInput is the input for agentic_watch.
+type WatchInput struct {
+	// Workspaces to watch. If empty, watches all running/queued workspaces.
+	Workspaces []string `json:"workspaces,omitempty"`
+	// PollInterval in seconds (default: 5)
+	PollInterval int `json:"poll_interval,omitempty"`
+	// Timeout in seconds (default: 600 = 10 minutes)
+	Timeout int `json:"timeout,omitempty"`
+}
+
+// WatchOutput is the result when all watched workspaces complete.
+type WatchOutput struct {
+	Success   bool          `json:"success"`
+	Completed []WatchResult `json:"completed"`
+	Failed    []WatchResult `json:"failed,omitempty"`
+	Duration  string        `json:"duration"`
+}
+
+// WatchResult describes one completed workspace.
+type WatchResult struct {
+	Workspace string `json:"workspace"`
+	Agent     string `json:"agent"`
+	Repo      string `json:"repo"`
+	Status    string `json:"status"`
+	PRURL     string `json:"pr_url,omitempty"`
+}
+
+func (s *PrepSubsystem) registerWatchTool(server *mcp.Server) {
+	mcp.AddTool(server, &mcp.Tool{
+		Name:        "agentic_watch",
+		Description: "Watch running/queued agent workspaces until they all complete. Sends progress notifications as each agent finishes. Returns summary when all are done.",
+	}, s.watch)
+}
+
+func (s *PrepSubsystem) watch(ctx context.Context, req *mcp.CallToolRequest, input WatchInput) (*mcp.CallToolResult, WatchOutput, error) {
+	pollInterval := time.Duration(input.PollInterval) * time.Second
+	if pollInterval <= 0 {
+		pollInterval = 5 * time.Second
+	}
+	timeout := time.Duration(input.Timeout) * time.Second
+	if timeout <= 0 {
+		timeout = 10 * time.Minute
+	}
+
+	start := time.Now()
+	deadline := start.Add(timeout)
+
+	// Find workspaces to watch
+	targets := input.Workspaces
+	if len(targets) == 0 {
+		targets = s.findActiveWorkspaces()
+	}
+
+	if len(targets) == 0 {
+		return nil, WatchOutput{
+			Success:  true,
+			Duration: "0s",
+		}, nil
+	}
+
+	var completed []WatchResult
+	var failed []WatchResult
+	remaining := make(map[string]bool)
+	for _, ws := range targets {
+		remaining[ws] = true
+	}
+
+	progressCount := float64(0)
+	total := float64(len(targets))
+
+	// Get progress token from request
+	progressToken := req.Params.GetProgressToken()
+
+	// Poll until all complete or timeout
+	for len(remaining) > 0 {
+		if time.Now().After(deadline) {
+			for ws := range remaining {
+				failed = append(failed, WatchResult{
+					Workspace: ws,
+					Status:    "timeout",
+				})
+			}
+			break
+		}
+
+		select {
+		case <-ctx.Done():
+			return nil, WatchOutput{}, coreerr.E("watch", "cancelled", ctx.Err())
+		case <-time.After(pollInterval):
+		}
+
+		for ws := range remaining {
+			wsDir := s.resolveWorkspaceDir(ws)
+			st, err := readStatus(wsDir)
+			if err != nil {
+				continue
+			}
+
+			switch st.Status {
+			case "completed":
+				result := WatchResult{
+					Workspace: ws,
+					Agent:     st.Agent,
+					Repo:      st.Repo,
+					Status:    "completed",
+					PRURL:     st.PRURL,
+				}
+				completed = append(completed, result)
+				delete(remaining, ws)
+				progressCount++
+
+				if progressToken != nil && req.Session != nil {
+					req.Session.NotifyProgress(ctx, &mcp.ProgressNotificationParams{
+						ProgressToken: progressToken,
+						Progress:      progressCount,
+						Total:         total,
+						Message:       fmt.Sprintf("%s completed (%s)", st.Repo, st.Agent),
+					})
+				}
+
+			case "failed", "blocked":
+				result := WatchResult{
+					Workspace: ws,
+					Agent:     st.Agent,
+					Repo:      st.Repo,
+					Status:    st.Status,
+				}
+				failed = append(failed, result)
+				delete(remaining, ws)
+				progressCount++
+
+				if progressToken != nil && req.Session != nil {
+					req.Session.NotifyProgress(ctx, &mcp.ProgressNotificationParams{
+						ProgressToken: progressToken,
+						Progress:      progressCount,
+						Total:         total,
+						Message:       fmt.Sprintf("%s %s (%s)", st.Repo, st.Status, st.Agent),
+					})
+				}
+			}
+		}
+	}
+
+	return nil, WatchOutput{
+		Success:   len(failed) == 0,
+		Completed: completed,
+		Failed:    failed,
+		Duration:  time.Since(start).Round(time.Second).String(),
+	}, nil
+}
+
+// findActiveWorkspaces returns workspace names that are running or queued.
+func (s *PrepSubsystem) findActiveWorkspaces() []string {
+	wsRoot := s.workspaceRoot()
+	entries, err := filepath.Glob(filepath.Join(wsRoot, "*/status.json"))
+	if err != nil {
+		return nil
+	}
+
+	var active []string
+	for _, entry := range entries {
+		wsDir := filepath.Dir(entry)
+		st, err := readStatus(wsDir)
+		if err != nil {
+			continue
+		}
+		if st.Status == "running" || st.Status == "queued" {
+			active = append(active, filepath.Base(wsDir))
+		}
+	}
+	return active
+}
+
+// resolveWorkspaceDir converts a workspace name to full path.
+func (s *PrepSubsystem) resolveWorkspaceDir(name string) string {
+	if filepath.IsAbs(name) {
+		return name
+	}
+	return filepath.Join(s.workspaceRoot(), name)
+}
+
+// workspaceRoot returns the root directory for agent workspaces.
+func (s *PrepSubsystem) workspaceRoot() string {
+	home, _ := os.UserHomeDir()
+	return filepath.Join(home, "Code", "host-uk", "core", ".core", "workspace")
+}