Struct Manager

agent/x/agentmcp/manager.go:77–131

Manager manages connections to MCP servers discovered from a workspace's .mcp.json file. It caches the aggregated tool list and proxies tool calls to the appropriate server.

// workspace's .mcp.json file. It caches the aggregated tool list
// and proxies tool calls to the appropriate server.
type Manager struct {
	ctx       context.Context
	cancel    context.CancelFunc
	execer    agentexec.Execer
	updateEnv func(current []string) ([]string, error)

	mu        sync.RWMutex
	logger    slog.Logger
	clock     quartz.Clock
	closed    bool
	servers   map[string]*serverEntry
	tools     []workspacesdk.MCPToolInfo
	snapshot  map[string]fileSnapshot
	serverGen uint64
	sf        tailscalesingleflight.Group[string, struct{}]

	// startupSettled is closed once startup scripts reach a terminal
	// state. Before that, missing MCP config files are unknown
	// because startup scripts may still create them.
	startupSettled chan struct{}
	startupOnce    sync.Once

	// firstSyncSettled records that a reload body reached a
	// terminal result, successful or not. It gates whether callers
	// may receive cached tools after reload errors.
	firstSyncSettled bool

	// closedCh is closed by Close to unblock waiters that do not
	// otherwise observe Close (the parent ctx is owned by the
	// caller and may outlive Close).
	closedCh  chan struct{}
	closeOnce sync.Once

	// lastPaths records the most recent config paths passed to
	// Reload/Tools. The fsnotify-backed watcher uses these to
	// drive its own reloads when ~/.mcp.json appears late on
	// dual-agent workspaces.
	lastPaths []string

	// watcher fires a debounced Reload when any watched config
	// file is created, written, removed, or renamed. It is armed
	// lazily on the first Reload call so tests that never call
	// Reload do not pay for an extra goroutine and file
	// descriptor.
	watcher       *configWatcher
	watcherOnce   sync.Once
	watchDebounce time.Duration

	// connectStartedHook is a test hook invoked at the start of
	// connectAll, before any client is dialed. Production code
	// leaves this nil; tests set it to coordinate with an
	// in-flight reload (for example, to verify Close()'s
	// shutdown ordering does not stall on a stuck connect).
	connectStartedHook func()
}

// serverEntry pairs a server config with its connected client.
type serverEntry struct {