Merge pull request #17 from Sagit-chu/opencode/curious-nebula

fix(gost): add fallback when FailFilter excludes all nodes

go-gost/x/hop/hop.go

@@ -201,11 +201,26 @@ func (p *chainHop) Select(ctx context.Context, opts ...hop.SelectOption) *chain.
 		return nodes[0]
 	}
 
-	// Always go through selector for proper FailFilter evaluation,
-	// even when there's only one node. This ensures failed nodes
-	// can be filtered out properly.
+	// For single-node case: bypass selector/FailFilter to ensure availability.
+	// The marker system still works for metrics, but we don't block requests
+	// based on recent failures - the connection will be attempted regardless.
+	// This matches upstream go-gost/x behavior.
+	if len(nodes) == 1 {
+		return nodes[0]
+	}
+
+	// Multi-node case: use selector with FailFilter for proper failover.
+	// FailFilter will exclude recently-failed nodes, allowing traffic to
+	// be routed to healthy alternatives.
 	if s := p.options.selector; s != nil {
-		return s.Select(ctx, nodes...)
+		if node := s.Select(ctx, nodes...); node != nil {
+			return node
+		}
+		// All nodes filtered out by FailFilter - all are marked as failed.
+		// Return nil to signal "no healthy nodes available" to the caller.
+		// The handler's retry loop will handle this appropriately.
+		log.Debugf("all %d nodes filtered out by FailFilter, no healthy nodes available", len(nodes))
+		return nil
 	}
 
 	// Fallback: return first node if no selector configured

go-gost/x/registry/AGENTS.md

@@ -0,0 +1,29 @@
+# GO-GOST REGISTRY KNOWLEDGE BASE
+
+**Generated:** Wed Feb 04 2026
+
+## OVERVIEW
+Central registration point for all pluggable GOST components (handlers, listeners, dialers, etc.).
+Allows the configuration system to resolve string types (e.g., "socks5") to actual Go implementations.
+
+## STRUCTURE
+One file per component type, exporting a standard Registry interface.
+```
+go-gost/x/registry/
+├── handler.go    # RegisterHandler(name, newFunc)
+├── listener.go   # RegisterListener(name, newFunc)
+├── dialer.go     # RegisterDialer(name, newFunc)
+└── ...           # Same pattern for auth, bypass, admission
+```
+
+## WHERE TO LOOK
+| Task | Location | Notes |
+|------|----------|-------|
+| Register a new component | `go-gost/x/registry/{type}.go` | Use `Register{Type}(name, creator)` |
+| Component lookup | `go-gost/x/registry/{type}.go` | `Get{Type}(name)` returns the creator function |
+| Default registrations | `go-gost/x/` (init functions) | Most components register themselves in their package `init()` |
+
+## CONVENTIONS
+- Thread-safe maps used for storage.
+- Names are case-sensitive (usually lowercase).
+- Components must be registered *before* the configuration parser runs (usually done via `import _ "..."` in `main.go`).

go-gost/x/selector/filter.go

@@ -24,11 +24,12 @@ func FailFilter[T any](maxFails int, timeout time.Duration) selector.Filter[T] {
 }
 
 // Filter filters dead objects.
-// Note: We intentionally do NOT skip filtering when len(vs) <= 1.
-// This ensures that even a single dead node gets filtered out,
-// allowing the caller to know that no healthy nodes are available
-// and potentially trigger failover behavior.
+// For single-node case, skip filtering to ensure availability (matches upstream).
+// For multi-node case, filter out failed nodes to enable failover.
 func (f *failFilter[T]) Filter(ctx context.Context, vs ...T) []T {
+	if len(vs) <= 1 {
+		return vs
+	}
 	var l []T
 	for _, v := range vs {
 		maxFails := f.maxFails