feature/servers logs (#10)

* Enhance logging system and add tail_log operation

- Updated logging configuration to support custom log directories and filenames.
- Introduced `tail_log` operation for reading recent log entries from upstream servers, aiding in debugging.
- Improved log structure and content for better traceability of MCP server interactions.
- Adjusted CLI commands and documentation to reflect new logging features and configurations.

* Add GetLogDir method to ServerInterface and implement log directory handling

- Introduced GetLogDir method in ServerInterface for retrieving the log directory path.
- Implemented GetLogDir in Server to return configured log directory or default paths.
- Updated tray application to include functionality for opening the logs directory.
- Enhanced error handling and logging for directory access operations.

* Update log file references from 'mcpproxy.log' to 'main.log' across workflows and internal logging configurations

* Update README and workflow documentation for system tray flag usage; clarify command-line options for enabling/disabling system tray functionality.

* Refactor logging levels in logger.go to use constants for improved readability and maintainability

Author: Dumbris

.github/workflows/e2e-tests.yml

@@ -118,9 +118,9 @@ jobs:
 
           # Verify log file was created in standard OS location
           if [ "$(uname)" = "Linux" ]; then
-            if [ -f "$HOME/.local/state/mcpproxy/logs/mcpproxy.log" ]; then
+            if [ -f "$HOME/.local/state/mcpproxy/logs/main.log" ]; then
               echo "✓ Log file created in Linux standard location"
-              head -5 "$HOME/.local/state/mcpproxy/logs/mcpproxy.log"
+              head -5 "$HOME/.local/state/mcpproxy/logs/main.log"
             else
               echo "⚠ Log file not found in expected location"
             fi
@@ -219,20 +219,20 @@ jobs:
             ls -la "${{ matrix.log_path_check }}"
             
             # Check if log file exists and has content
-            if [ -f "${{ matrix.log_path_check }}/mcpproxy.log" ]; then
+            if [ -f "${{ matrix.log_path_check }}/main.log" ]; then
               echo "✓ Log file created successfully"
-              echo "Log file size: $(wc -c < "${{ matrix.log_path_check }}/mcpproxy.log") bytes"
+              echo "Log file size: $(wc -c < "${{ matrix.log_path_check }}/main.log") bytes"
               echo "First few lines:"
-              head -3 "${{ matrix.log_path_check }}/mcpproxy.log"
+              head -3 "${{ matrix.log_path_check }}/main.log"
               
               # Verify log contains expected content
-              if grep -q "Log directory configured" "${{ matrix.log_path_check }}/mcpproxy.log"; then
+              if grep -q "Log directory configured" "${{ matrix.log_path_check }}/main.log"; then
                 echo "✓ Log contains expected startup messages"
               else
                 echo "⚠ Log missing expected startup messages"
               fi
               
-              if grep -q "${{ matrix.log_standard }}" "${{ matrix.log_path_check }}/mcpproxy.log"; then
+              if grep -q "${{ matrix.log_standard }}" "${{ matrix.log_path_check }}/main.log"; then
                 echo "✓ Log contains OS standard compliance information"
               else
                 echo "⚠ Log missing OS standard compliance information"
@@ -274,7 +274,7 @@ jobs:
           Get-ChildItem $logPath
 
           # Check if log file exists and has content
-          $logFile = Join-Path $logPath "mcpproxy.log"
+          $logFile = Join-Path $logPath "main.log"
           if (-not (Test-Path $logFile)) {
             Write-Host "✗ Log file not created"
             exit 1

.github/workflows/release.yml

@@ -549,7 +549,7 @@ jobs:
 
             - With tray: `./mcpproxy` (default)
             - Custom port (default: 8080): `./mcpproxy --listen :8081`
-            - Headless: `./mcpproxy --tray false`
+            - Headless: `./mcpproxy --tray=false`
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 

DESIGN.md

@@ -24,12 +24,12 @@ Re‑implement the existing Python MCP proxy in Go, delivering a single‑binary
 
 * WebSocket/stdin transports, distributed indexing, vector search.
 
-## 3  Tech Stack
+## 3  Tech Stack
 
 | Concern           | Library                           | Reason                             |
 | ----------------- | --------------------------------- | ---------------------------------- |
 | MCP server/client | **`mark3labs/mcp-go`**            | Native Go, Streamable‑HTTP support |
-| Full‑text search  | **Bleve v2**                      | Embeddable BM25                    |
+| Full‑text search  | **Bleve v2**                      | Embeddable BM25                    |
 | CLI & config      | **`spf13/cobra` + `spf13/viper`** | Flags → env → file binding         |
 | Persistence       | **bbolt**                         | Single‑file ACID                   |
 | Sys‑tray          | **`fyne.io/systray`**             | Tiny cross‑platform tray           |
@@ -66,7 +66,7 @@ Re‑implement the existing Python MCP proxy in Go, delivering a single‑binary
   * Stored alongside tool metadata in both Bleve doc and Bolt `toolhash` bucket.
   * During re‑sync `ListTools` results are hashed; unchanged hashes skip re‑indexing.
 
-## 6  Data Model (bbolt)
+## 6  Data Model (bbolt)
 
 | Bucket      | Key           | Value                        |
 | ----------- | ------------- | ---------------------------- |
@@ -119,7 +119,22 @@ Input:  {"operation":"add","url":"https://api.mcp.dev","name":"dev"}
 Output: {"id":"uuid","enabled":true}
 ```
 
-Operations: `list` / `add` / `remove` / `update`.
+Operations: `list` / `add` / `remove` / `update` / `tail_log`.
+
+#### 8.3.1 `tail_log` Operation
+
+The `tail_log` operation allows LLMs to read recent log entries from a specific upstream server for debugging purposes:
+
+```jsonc
+Input:  {"operation":"tail_log","name":"dev","lines":50}
+Output: {"server":"dev","lines":50,"log_entries":[...]}
+```
+
+**Parameters:**
+- `name` (required): Server name to read logs from
+- `lines` (optional): Number of recent lines to return (default: 50, max: 500)
+
+**Use Case:** Enables AI agents to autonomously diagnose connection issues, authentication failures, and other upstream server problems by reading recent log entries.
 
 ### 8.4  `tools_stat`
 
@@ -134,10 +149,55 @@ Returns `{total_tools, top:[{tool_name,count}]}`.
 
 ## 10  CLI, Config & Tray
 
-* `mcpproxy [--listen :8080] [--data-dir ~/.mcpproxy] [--upstream "prod=https://api"]`
+* `mcpproxy [--listen :8080] [--log-dir ~/.mcpproxy/logs] [--upstream "prod=https://api"]`
 * Viper reads `$MCPP_` envs and `config.toml`.
 * Tray (systray): icon + menu items (Enable, Disable, Add…, Reindex, Quit).
 
+### 10.1 Logging System
+
+#### Per-Upstream Server Logging
+
+mcpproxy implements comprehensive per-upstream-server logging to facilitate debugging of connection issues and MCP communication problems.
+
+**Log File Structure:**
+```
+~/.mcpproxy/logs/
+├── main.log                    # Main application log
+├── server-github.log           # GitHub MCP server interactions
+├── server-filesystem.log       # Filesystem MCP server interactions
+└── server-database.log         # Database MCP server interactions
+```
+
+**Log Content:**
+- **MCP Protocol Messages**: All JSON-RPC messages between mcpproxy and upstream servers
+- **Connection Events**: Connect, disconnect, retry attempts, and failures
+- **Authentication**: OAuth flows, token refreshes, and auth errors
+- **Process Output**: STDERR from stdio-based MCP servers
+- **Timing Information**: Request/response latencies and timeout events
+
+**Example Log Format:**
+```
+2025-06-04T03:42:38.375Z [github] [info] Connecting to upstream server
+2025-06-04T03:42:38.630Z [github] [info] Connected successfully
+2025-06-04T03:42:38.663Z [github] [debug] [Client→Server] initialize
+2025-06-04T03:42:38.663Z [github] [debug] {"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"mcpproxy-go","version":"1.0.0"}},"jsonrpc":"2.0","id":0}
+2025-06-04T03:42:38.700Z [github] [debug] [Server→Client] 0
+2025-06-04T03:42:38.700Z [github] [debug] {"jsonrpc":"2.0","id":0,"result":{"protocolVersion":"2024-11-05","capabilities":{"tools":{"listChanged":false}},"serverInfo":{"name":"GitHub MCP Server","version":"1.0.0"}}}
+2025-06-04T03:42:41.670Z [github] [error] Connection error: HTTP 500 - Internal Server Error
+2025-06-04T03:42:41.671Z [github] [info] Attempting reconnection in 5 seconds...
+```
+
+**CLI Configuration:**
+- `--log-dir`: Specify custom log directory (default: OS-specific standard location)
+- `--log-level`: Set log level for all loggers (debug, info, warn, error)
+- Main application log: `main.log`
+- Per-server logs: `server-{name}.log`
+
+**Log Rotation:**
+- Automatic rotation based on file size (10MB default)
+- Configurable retention (5 backup files, 30 days default)
+- Optional compression for rotated files
+
 ## 11  Build & Packaging
 
 * Cross‑compile via `GOOS=darwin/windows/linux`.
@@ -171,7 +231,10 @@ The proxy supports dynamic management of upstream MCP servers through the `upstr
 ~/.mcpproxy/
 ├── mcp_config.json          # Main configuration file
 ├── data.bolt                # BoltDB storage (tool stats, metadata)
-└── index.bleve/             # Search index directory
+├── index.bleve/             # Search index directory
+└── logs/                    # Log files directory
+    ├── main.log             # Main application log
+    └── server-*.log         # Per-upstream server logs
 ```
 
 #### Configuration Flow

README.md

@@ -116,7 +116,7 @@ mcpproxy --help
   -c, --config <file>          path to mcp_config.json
   -l, --listen <addr>          listen address (":8080")
   -d, --data-dir <dir>         custom data directory
-      --tray                   enable/disable system tray (default true)
+      --tray                   enable/disable system tray (default true, use --tray=false to disable)
       --log-level <level>      debug|info|warn|error
       --read-only              forbid config changes
       --disable-management     disable upstream_servers tool

cmd/mcpproxy/main.go

@@ -25,7 +25,7 @@ var (
 	debugSearch       bool
 	toolResponseLimit int
 	logToFile         bool
-	logFile           string
+	logDir            string
 
 	// Security flags
 	readOnlyMode      bool
@@ -57,11 +57,11 @@ func main() {
 	rootCmd.PersistentFlags().StringVarP(&dataDir, "data-dir", "d", "", "Data directory path (default: ~/.mcpproxy)")
 	rootCmd.PersistentFlags().StringVarP(&listen, "listen", "l", "", "Listen address (for HTTP mode, not used in stdio mode)")
 	rootCmd.PersistentFlags().StringVar(&logLevel, "log-level", "info", "Log level (debug, info, warn, error)")
-	rootCmd.PersistentFlags().BoolVar(&enableTray, "tray", true, "Enable system tray")
+	rootCmd.PersistentFlags().BoolVar(&enableTray, "tray", true, "Enable system tray (use --tray=false to disable)")
 	rootCmd.PersistentFlags().BoolVar(&debugSearch, "debug-search", false, "Enable debug search tool for search relevancy debugging")
 	rootCmd.PersistentFlags().IntVar(&toolResponseLimit, "tool-response-limit", 0, "Tool response limit in characters (0 = disabled, default: 20000 from config)")
 	rootCmd.PersistentFlags().BoolVar(&logToFile, "log-to-file", true, "Enable logging to file in standard OS location")
-	rootCmd.PersistentFlags().StringVar(&logFile, "log-file", "", "Custom log file path (overrides standard OS location)")
+	rootCmd.PersistentFlags().StringVar(&logDir, "log-dir", "", "Custom log directory path (overrides standard OS location)")
 	rootCmd.PersistentFlags().BoolVar(&readOnlyMode, "read-only", false, "Enable read-only mode")
 	rootCmd.PersistentFlags().BoolVar(&disableManagement, "disable-management", false, "Disable management features")
 	rootCmd.PersistentFlags().BoolVar(&allowServerAdd, "allow-server-add", true, "Allow adding new servers")
@@ -74,7 +74,7 @@ func main() {
 	}
 }
 
-func runServer(_ *cobra.Command, _ []string) error {
+func runServer(cmd *cobra.Command, _ []string) error {
 	// Load configuration first to get logging settings
 	cfg, err := loadConfig()
 	if err != nil {
@@ -87,7 +87,7 @@ func runServer(_ *cobra.Command, _ []string) error {
 			Level:         logLevel,
 			EnableFile:    logToFile,
 			EnableConsole: true,
-			Filename:      "mcpproxy.log",
+			Filename:      "main.log",
 			MaxSize:       10,
 			MaxBackups:    5,
 			MaxAge:        30,
@@ -98,11 +98,16 @@ func runServer(_ *cobra.Command, _ []string) error {
 		// Override specific fields from command line
 		cfg.Logging.Level = logLevel
 		cfg.Logging.EnableFile = logToFile
-		if logFile != "" {
-			cfg.Logging.Filename = logFile
+		if cfg.Logging.Filename == "" || cfg.Logging.Filename == "mcpproxy.log" {
+			cfg.Logging.Filename = "main.log"
 		}
 	}
 
+	// Override log directory if specified
+	if logDir != "" {
+		cfg.Logging.LogDir = logDir
+	}
+
 	// Setup logger with new logging system
 	logger, err := logs.SetupLogger(cfg.Logging)
 	if err != nil {
@@ -130,7 +135,10 @@ func runServer(_ *cobra.Command, _ []string) error {
 		zap.Bool("log_to_file", logToFile))
 
 	// Override other settings from command line
-	cfg.EnableTray = enableTray
+	// Check if the tray flag was explicitly set by the user
+	if cmd.Flags().Changed("tray") {
+		cfg.EnableTray = enableTray
+	}
 	cfg.DebugSearch = debugSearch
 
 	if toolResponseLimit != 0 {

internal/config/config.go

@@ -39,9 +39,10 @@ type LogConfig struct {
 	EnableFile    bool   `json:"enable_file" mapstructure:"enable-file"`
 	EnableConsole bool   `json:"enable_console" mapstructure:"enable-console"`
 	Filename      string `json:"filename" mapstructure:"filename"`
-	MaxSize       int    `json:"max_size" mapstructure:"max-size"`       // MB
-	MaxBackups    int    `json:"max_backups" mapstructure:"max-backups"` // number of backup files
-	MaxAge        int    `json:"max_age" mapstructure:"max-age"`         // days
+	LogDir        string `json:"log_dir,omitempty" mapstructure:"log-dir"` // Custom log directory
+	MaxSize       int    `json:"max_size" mapstructure:"max-size"`         // MB
+	MaxBackups    int    `json:"max_backups" mapstructure:"max-backups"`   // number of backup files
+	MaxAge        int    `json:"max_age" mapstructure:"max-age"`           // days
 	Compress      bool   `json:"compress" mapstructure:"compress"`
 	JSONFormat    bool   `json:"json_format" mapstructure:"json-format"`
 }
@@ -158,7 +159,7 @@ func DefaultConfig() *Config {
 			Level:         "info",
 			EnableFile:    true,
 			EnableConsole: true,
-			Filename:      "mcpproxy.log",
+			Filename:      "main.log",
 			MaxSize:       10, // 10MB
 			MaxBackups:    5,  // 5 backup files
 			MaxAge:        30, // 30 days

internal/config/loader.go

@@ -139,7 +139,6 @@ func setupViper() {
 
 	// Set defaults
 	viper.SetDefault("listen", ":8080")
-	viper.SetDefault("tray", true)
 	viper.SetDefault("top-k", 5)
 	viper.SetDefault("tools-limit", 15)
 	viper.SetDefault("config", "")