feat: add vfs stats --json cmd

AGENTS.md

@@ -213,7 +213,7 @@ All tools use the same MCP server config. The only difference is where the confi
 | Tool | Config location |
 |------|----------------|
 | **Cursor** | `.cursor/mcp.json` (project) or `~/.cursor/mcp.json` (global) |
-| **Claude Code** | `.mcp.json` (project) or via `claude mcp add vfs -- vfs mcp` |
+| **Claude Code** | `claude mcp add vfs -- vfs mcp` (recommended) or `.mcp.json` (project) |
 | **Claude Desktop** | `~/Library/Application Support/Claude/claude_desktop_config.json` (macOS) |
 | **Antigravity** | MCP settings panel, or project MCP config. Also reads `AGENTS.md` / `GEMINI.md` |
 | **Windsurf** | `.windsurf/mcp.json` (project) or global via Windsurf settings |
@@ -222,6 +222,33 @@ All tools use the same MCP server config. The only difference is where the confi
 | **Zed** | `~/.config/zed/settings.json` under `context_servers` |
 | **Any HTTP client** | Point to `http://localhost:8080/mcp` after running `vfs up` (use `--port` for custom port) |
 
+### Claude Code setup
+
+**Recommended:** Use the CLI command (registers in `~/.claude.json` under project scope):
+
+```bash
+claude mcp add vfs -- vfs mcp
+```
+
+This is the most reliable method. Claude Code reads MCP configs from its own settings file (`~/.claude.json`), not from `.mcp.json`. Using `claude mcp add` ensures the server is registered in the right place.
+
+**Alternative:** Add a `.mcp.json` file at the project root:
+
+```json
+{
+  "mcpServers": {
+    "vfs": {
+      "command": "vfs",
+      "args": ["mcp"]
+    }
+  }
+}
+```
+
+> **Note:** Claude Code uses stdio transport for local MCP servers. Do NOT use `"type": "sse"` or `"type": "http"` — those are for HTTP-based tools like Cursor. If `.mcp.json` is not being picked up, use `claude mcp add` instead.
+
+### Other tools (Cursor, Windsurf, Cline, etc.)
+
 The stdio config (works for most tools):
 
 ```json

VERSION

@@ -1 +1 @@
-1.2.13
+1.2.14

cmd/vfs/stats_cmd.go

@@ -1,13 +1,16 @@
 package main
 
 import (
+	"encoding/json"
 	"fmt"
+	"os"
 
 	"github.com/TrNgTien/vfs/internal/stats"
 	"github.com/spf13/cobra"
 )
 
 var statsReset bool
+var statsJSON bool
 
 var statsCmd = &cobra.Command{
 	Use:   "stats",
@@ -17,6 +20,7 @@ var statsCmd = &cobra.Command{
 
 func init() {
 	statsCmd.Flags().BoolVar(&statsReset, "reset", false, "clear all history")
+	statsCmd.Flags().BoolVar(&statsJSON, "json", false, "output as JSON")
 }
 
 func runStats(cmd *cobra.Command, args []string) error {
@@ -39,6 +43,12 @@ func runStats(cmd *cobra.Command, args []string) error {
 
 	s := stats.Summarize(entries)
 
+	if statsJSON {
+		enc := json.NewEncoder(os.Stdout)
+		enc.SetIndent("", "  ")
+		return enc.Encode(s)
+	}
+
 	fmt.Println("--- vfs lifetime stats ---")
 	fmt.Printf("Invocations:         %d\n", s.Invocations)
 	fmt.Printf("Total tokens saved:  ~%s\n", formatTokenCount(s.TotalSaved))

internal/stats/stats.go

@@ -26,21 +26,21 @@ type Entry struct {
 }
 
 type Summary struct {
-	Invocations   int
-	TotalRawBytes int64
-	TotalRawLines int
-	TotalVFSBytes int64
-	TotalVFSLines int
-	TotalSaved    int64
-	AvgReduction  float64
-	FirstRecorded time.Time
-	LastRecorded  time.Time
-
-	Searches      int
-	Extracts      int
-	AvgDurationMs float64
-	SearchHitRate float64
-	EmptySearches int
+	Invocations   int       `json:"invocations"`
+	TotalRawBytes int64     `json:"total_raw_bytes"`
+	TotalRawLines int       `json:"total_raw_lines"`
+	TotalVFSBytes int64     `json:"total_vfs_bytes"`
+	TotalVFSLines int       `json:"total_vfs_lines"`
+	TotalSaved    int64     `json:"total_saved"`
+	AvgReduction  float64   `json:"avg_reduction"`
+	FirstRecorded time.Time `json:"first_recorded"`
+	LastRecorded  time.Time `json:"last_recorded"`
+
+	Searches      int     `json:"searches"`
+	Extracts      int     `json:"extracts"`
+	AvgDurationMs float64 `json:"avg_duration_ms"`
+	SearchHitRate float64 `json:"search_hit_rate"`
+	EmptySearches int     `json:"empty_searches"`
 }
 
 func historyPath() string {