fix: add client-side caching to eliminate redundant terminfo installations

- Cache known hosts with terminfo in
$GHOSTTY_RESOURCES_DIR/terminfo_hosts
- Skip installation step for cached hosts (single connection instead of
two)
- Use secure file permissions (600) and atomic writes
- Extract SSH target safely from command arguments
- Maintains full functionality while improving user experience on
repeated connections

4 files changed, 367 insertions, 52 deletions

diff --git a/src/shell-integration/bash/ghostty.bash b/src/shell-integration/bash/ghostty.bash
index 2ce1f9503..51ab6c3e5 100644
--- a/src/shell-integration/bash/ghostty.bash
+++ b/src/shell-integration/bash/ghostty.bash
@@ -99,6 +99,66 @@ fi
 
 # SSH
 if [[ -n "$GHOSTTY_SSH_INTEGRATION" ]]; then
+  # Cache file for tracking hosts with terminfo installed
+  _ghostty_cache_file="${GHOSTTY_RESOURCES_DIR:-$HOME/.config/ghostty}/terminfo_hosts"
+
+  # Extract target host from SSH arguments
+  _ghostty_get_ssh_target() {
+    local target=""
+    local skip_next=false
+
+    for arg in "$@"; do
+      if [[ "$skip_next" == "true" ]]; then
+        skip_next=false
+        continue
+      fi
+
+      # Skip flags that take arguments
+      if [[ "$arg" =~ ^-[bcDEeFIiJLlmOopQRSWw]$ ]]; then
+        skip_next=true
+        continue
+      fi
+
+      # Skip other flags
+      if [[ "$arg" =~ ^- ]]; then
+        continue
+      fi
+
+      # This should be the target
+      target="$arg"
+      break
+    done
+
+    echo "$target"
+  }
+
+  # Check if host has terminfo installed
+  _ghostty_host_has_terminfo() {
+    local target="$1"
+    [[ -f "$_ghostty_cache_file" ]] && grep -qFx "$target" "$_ghostty_cache_file" 2>/dev/null
+  }
+
+  # Add host to terminfo cache
+  _ghostty_cache_host() {
+    local target="$1"
+    local cache_dir
+    cache_dir="$(dirname "$_ghostty_cache_file")"
+
+    # Create cache directory if needed
+    [[ ! -d "$cache_dir" ]] && mkdir -p "$cache_dir"
+
+    # Atomic write to cache file
+    {
+      if [[ -f "$_ghostty_cache_file" ]]; then
+        cat "$_ghostty_cache_file"
+      fi
+      echo "$target"
+    } | sort -u > "$_ghostty_cache_file.tmp" && mv "$_ghostty_cache_file.tmp" "$_ghostty_cache_file"
+
+    # Secure permissions
+    chmod 600 "$_ghostty_cache_file" 2>/dev/null
+  }
+
   # Wrap `ssh` command to provide Ghostty SSH integration.
   #
   # This approach supports wrapping an `ssh` alias, but the alias definition
@@ -153,21 +213,35 @@ if [[ -n "$GHOSTTY_SSH_INTEGRATION" ]]; then
 
   # Level: full - All features
   _ghostty_ssh_full() {
-    # Full integration: Two-step terminfo installation
-    if builtin command -v infocmp >/dev/null 2>&1; then
-      echo "Installing Ghostty terminfo on remote host..." >&2
-
-      # Step 1: Install terminfo
-      if infocmp -x xterm-ghostty 2>/dev/null | builtin command ssh "$@" 'tic -x - 2>/dev/null'; then
-        echo "Terminfo installed successfully. Connecting with full Ghostty support..." >&2
+    local target
+    target="$(_ghostty_get_ssh_target "$@")"
+
+    # Check if we already know this host has terminfo
+    if [[ -n "$target" ]] && _ghostty_host_has_terminfo "$target"; then
+      # Direct connection with xterm-ghostty
+      local env_vars=("TERM=xterm-ghostty")
+      [[ -n "$GHOSTTY_SHELL_FEATURES" ]] && env_vars+=("GHOSTTY_SHELL_FEATURES=$GHOSTTY_SHELL_FEATURES")
+      env "${env_vars[@]}" ssh "$@"
+      return 0
+    fi
 
-        # Step 2: Connect with xterm-ghostty since we know terminfo is now available
+    # Full integration: Install terminfo if needed
+    if builtin command -v infocmp >/dev/null 2>&1; then
+      # Install terminfo only if needed
+      if infocmp -x xterm-ghostty 2>/dev/null | builtin command ssh "$@" '
+          if ! infocmp xterm-ghostty >/dev/null 2>&1; then
+              echo "Installing Ghostty terminfo..." >&2
+              tic -x - 2>/dev/null
+          fi
+      '; then
+        echo "Connecting with full Ghostty support..." >&2
+
+        # Cache this host for future connections
+        [[ -n "$target" ]] && _ghostty_cache_host "$target"
+
+        # Connect with xterm-ghostty since terminfo is available
         local env_vars=("TERM=xterm-ghostty")
-
-        # Propagate Ghostty shell integration environment variables
         [[ -n "$GHOSTTY_SHELL_FEATURES" ]] && env_vars+=("GHOSTTY_SHELL_FEATURES=$GHOSTTY_SHELL_FEATURES")
-
-        # Normal SSH connection with Ghostty terminfo available
         env "${env_vars[@]}" ssh "$@"
         builtin return 0
       fi
diff --git a/src/shell-integration/elvish/lib/ghostty-integration.elv b/src/shell-integration/elvish/lib/ghostty-integration.elv
index 2f938df97..deb258ae7 100644
--- a/src/shell-integration/elvish/lib/ghostty-integration.elv
+++ b/src/shell-integration/elvish/lib/ghostty-integration.elv
@@ -98,6 +98,70 @@
     (external sudo) $@args
   }
 
+  # SSH Integration
+  # Cache file for tracking hosts with terminfo installed
+  var ghostty-cache-file = (if (has-env GHOSTTY_RESOURCES_DIR) { put $E:GHOSTTY_RESOURCES_DIR"/terminfo_hosts" } else { put $E:HOME"/.config/ghostty/terminfo_hosts" })
+
+  # Extract target host from SSH arguments
+  fn ghostty-get-ssh-target {|@args|
+    var target = ""
+    var skip-next = $false
+
+    for arg $args {
+      if (eq $skip-next $true) {
+        set skip-next = $false
+        continue
+      }
+
+      # Skip flags that take arguments
+      if (re:match '^-[bcDEeFIiJLlmOopQRSWw]$' $arg) {
+        set skip-next = $true
+        continue
+      }
+
+      # Skip other flags
+      if (re:match '^-' $arg) {
+        continue
+      }
+
+      # This should be the target
+      set target = $arg
+      break
+    }
+
+    put $target
+  }
+
+  # Check if host has terminfo installed
+  fn ghostty-host-has-terminfo {|target|
+    and (path:is-regular $ghostty-cache-file) ?(grep -qFx $target $ghostty-cache-file 2>/dev/null)
+  }
+
+  # Add host to terminfo cache
+  fn ghostty-cache-host {|target|
+    var cache-dir = (path:dir $ghostty-cache-file)
+
+    # Create cache directory if needed
+    if (not (path:is-dir $cache-dir)) {
+      mkdir -p $cache-dir
+    }
+
+    # Atomic write to cache file
+    var temp-file = $ghostty-cache-file".tmp"
+
+    {
+      if (path:is-regular $ghostty-cache-file) {
+        cat $ghostty-cache-file
+      }
+      echo $target
+    } | sort -u > $temp-file
+
+    mv $temp-file $ghostty-cache-file
+
+    # Secure permissions
+    ?chmod 600 $ghostty-cache-file 2>/dev/null
+  }
+
   fn ssh-with-ghostty-integration {|@args|
     if (has-env GHOSTTY_SSH_INTEGRATION) {
       if (eq "term-only" $E:GHOSTTY_SSH_INTEGRATION) {
@@ -127,17 +191,17 @@
   fn ssh-basic {|@args|
     # Level: basic - TERM fix + environment variable propagation
     var env-vars = []
-    
+
     # Fix TERM compatibility
     if (eq "xterm-ghostty" $E:TERM) {
       set env-vars = (conj $env-vars TERM=xterm-256color)
     }
-    
+
     # Propagate Ghostty shell integration environment variables
     if (not-eq "" $E:GHOSTTY_SHELL_FEATURES) {
       set env-vars = (conj $env-vars GHOSTTY_SHELL_FEATURES=$E:GHOSTTY_SHELL_FEATURES)
     }
-    
+
     # Execute with environment variables if any were set
     if (> (count $env-vars) 0) {
       (external env) $@env-vars ssh $@args
@@ -147,22 +211,47 @@
   }
 
   fn ssh-full {|@args|
-    # Full integration: Two-step terminfo installation
+    var target = (ghostty-get-ssh-target $@args)
+
+    # Check if we already know this host has terminfo
+    if (and (not-eq "" $target) (ghostty-host-has-terminfo $target)) {
+      # Direct connection with xterm-ghostty
+      var env-vars = [TERM=xterm-ghostty]
+
+      # Propagate Ghostty shell integration environment variables
+      if (not-eq "" $E:GHOSTTY_SHELL_FEATURES) {
+        set env-vars = (conj $env-vars GHOSTTY_SHELL_FEATURES=$E:GHOSTTY_SHELL_FEATURES)
+      }
+
+      (external env) $@env-vars ssh $@args
+      return
+    }
+
+    # Full integration: Install terminfo if needed
     if (has-external infocmp) {
-      echo "Installing Ghostty terminfo on remote host..." >&2
-      
       try {
-        infocmp -x xterm-ghostty 2>/dev/null | (external ssh) $@args 'tic -x - 2>/dev/null'
-        echo "Terminfo installed successfully. Connecting with full Ghostty support..." >&2
-        
-        # Step 2: Connect with xterm-ghostty since we know terminfo is now available
+        # Install terminfo only if needed
+        infocmp -x xterm-ghostty 2>/dev/null | (external ssh) $@args '
+          if ! infocmp xterm-ghostty >/dev/null 2>&1; then
+            echo "Installing Ghostty terminfo..." >&2
+            tic -x - 2>/dev/null
+          fi
+        '
+        echo "Connecting with full Ghostty support..." >&2
+
+        # Cache this host for future connections
+        if (not-eq "" $target) {
+          ghostty-cache-host $target
+        }
+
+        # Connect with xterm-ghostty since terminfo is available
         var env-vars = [TERM=xterm-ghostty]
-        
+
         # Propagate Ghostty shell integration environment variables
         if (not-eq "" $E:GHOSTTY_SHELL_FEATURES) {
           set env-vars = (conj $env-vars GHOSTTY_SHELL_FEATURES=$E:GHOSTTY_SHELL_FEATURES)
         }
-        
+
         # Normal SSH connection with Ghostty terminfo available
         (external env) $@env-vars ssh $@args
         return
@@ -170,15 +259,16 @@
         echo "Terminfo installation failed. Using basic integration." >&2
       }
     }
-    
+
     # Fallback to basic integration
     ssh-basic $@args
   }
 
-# Register SSH integration if enabled
+  # Register SSH integration if enabled
   if (and (has-env GHOSTTY_SSH_INTEGRATION) (has-external ssh)) {
     edit:add-var ssh~ $ssh-with-ghostty-integration~
-  }
+  } 
+
   defer {
     mark-prompt-start
     report-pwd
diff --git a/src/shell-integration/fish/vendor_conf.d/ghostty-shell-integration.fish b/src/shell-integration/fish/vendor_conf.d/ghostty-shell-integration.fish
index 0fe7155a1..bcf97cb82 100644
--- a/src/shell-integration/fish/vendor_conf.d/ghostty-shell-integration.fish
+++ b/src/shell-integration/fish/vendor_conf.d/ghostty-shell-integration.fish
@@ -86,8 +86,68 @@ function __ghostty_setup --on-event fish_prompt -d "Setup ghostty integration"
         end
     end
 
-    # SSH integration wrapper
+    # SSH integration
     if test -n "$GHOSTTY_SSH_INTEGRATION"
+        # Cache file for tracking hosts with terminfo installed
+        set -l _ghostty_cache_file (string join / (test -n "$GHOSTTY_RESOURCES_DIR"; and echo "$GHOSTTY_RESOURCES_DIR"; or echo "$HOME/.config/ghostty") "terminfo_hosts")
+
+        # Extract target host from SSH arguments
+        function _ghostty_get_ssh_target
+            set -l target ""
+            set -l skip_next false
+
+            for arg in $argv
+                if test "$skip_next" = "true"
+                    set skip_next false
+                    continue
+                end
+
+                # Skip flags that take arguments
+                if string match -qr '^-[bcDEeFIiJLlmOopQRSWw]$' -- "$arg"
+                    set skip_next true
+                    continue
+                end
+
+                # Skip other flags
+                if string match -q -- '-*' "$arg"
+                    continue
+                end
+
+                # This should be the target
+                set target "$arg"
+                break
+            end
+
+            echo "$target"
+        end
+
+        # Check if host has terminfo installed
+        function _ghostty_host_has_terminfo
+            set -l target $argv[1]
+            test -f "$_ghostty_cache_file"; and grep -qFx "$target" "$_ghostty_cache_file" 2>/dev/null
+        end
+
+        # Add host to terminfo cache
+        function _ghostty_cache_host
+            set -l target $argv[1]
+            set -l cache_dir (dirname "$_ghostty_cache_file")
+
+            # Create cache directory if needed
+            test -d "$cache_dir"; or mkdir -p "$cache_dir"
+
+            # Atomic write to cache file
+            begin
+                if test -f "$_ghostty_cache_file"
+                    cat "$_ghostty_cache_file"
+                end
+                echo "$target"
+            end | sort -u > "$_ghostty_cache_file.tmp"; and mv "$_ghostty_cache_file.tmp" "$_ghostty_cache_file"
+
+            # Secure permissions
+            chmod 600 "$_ghostty_cache_file" 2>/dev/null
+        end
+
+        # Wrap `ssh` command to provide Ghostty SSH integration.
         function ssh -d "Wrap ssh to provide Ghostty SSH integration"
             switch "$GHOSTTY_SSH_INTEGRATION"
                 case term-only
@@ -136,22 +196,38 @@ function __ghostty_setup --on-event fish_prompt -d "Setup ghostty integration"
 
         # Level: full - All features
         function _ghostty_ssh_full
-            # Full integration: Two-step terminfo installation
+            set -l target (_ghostty_get_ssh_target $argv)
+
+            # Check if we already know this host has terminfo
+            if test -n "$target"; and _ghostty_host_has_terminfo "$target"
+                # Direct connection with xterm-ghostty
+                set --local env_vars TERM=xterm-ghostty
+                if test -n "$GHOSTTY_SHELL_FEATURES"
+                    set --append env_vars GHOSTTY_SHELL_FEATURES="$GHOSTTY_SHELL_FEATURES"
+                end
+                env $env_vars ssh $argv
+                return 0
+            end
+
+            # Full integration: Install terminfo if needed
             if type -q infocmp
-                echo "Installing Ghostty terminfo on remote host..." >&2
+                # Install terminfo only if needed
+                if infocmp -x xterm-ghostty 2>/dev/null | ssh $argv '
+                    if ! infocmp xterm-ghostty >/dev/null 2>&1
+                        echo "Installing Ghostty terminfo..." >&2
+                        tic -x - 2>/dev/null
+                    end
+                '
+                    echo "Connecting with full Ghostty support..." >&2
+
+                    # Cache this host for future connections
+                    test -n "$target"; and _ghostty_cache_host "$target"
 
-                # Step 1: Install terminfo 
-                if infocmp -x xterm-ghostty 2>/dev/null | ssh $argv 'tic -x - 2>/dev/null'
-                    echo "Terminfo installed successfully. Connecting with full Ghostty support..." >&2
-                    
-                    # Step 2: Connect with xterm-ghostty since we know terminfo is now available
+                    # Connect with xterm-ghostty since terminfo is available
                     set --local env_vars TERM=xterm-ghostty
-                    
-                    # Propagate Ghostty shell integration environment variables
                     if test -n "$GHOSTTY_SHELL_FEATURES"
                         set --append env_vars GHOSTTY_SHELL_FEATURES="$GHOSTTY_SHELL_FEATURES"
                     end
-                    
                     env $env_vars ssh $argv
                     builtin return 0
                 end
@@ -162,6 +238,7 @@ function __ghostty_setup --on-event fish_prompt -d "Setup ghostty integration"
             _ghostty_ssh_basic $argv
         end
     end
+
     # Setup prompt marking
     function __ghostty_mark_prompt_start --on-event fish_prompt --on-event fish_cancel --on-event fish_posterror
         # If we never got the output end event, then we need to send it now.
diff --git a/src/shell-integration/zsh/ghostty-integration b/src/shell-integration/zsh/ghostty-integration
index 109c9fd60..c172fc02d 100644
--- a/src/shell-integration/zsh/ghostty-integration
+++ b/src/shell-integration/zsh/ghostty-integration
@@ -243,9 +243,69 @@ _ghostty_deferred_init() {
         fi
       }
     fi
-    
+
     # SSH
     if [[ -n "$GHOSTTY_SSH_INTEGRATION" ]]; then
+      # Cache file for tracking hosts with terminfo installed
+      _ghostty_cache_file="${GHOSTTY_RESOURCES_DIR:-$HOME/.config/ghostty}/terminfo_hosts"
+
+      # Extract target host from SSH arguments
+      _ghostty_get_ssh_target() {
+        local target=""
+        local skip_next=false
+
+        for arg in "$@"; do
+          if [[ "$skip_next" == "true" ]]; then
+            skip_next=false
+            continue
+          fi
+
+          # Skip flags that take arguments
+          if [[ "$arg" =~ ^-[bcDEeFIiJLlmOopQRSWw]$ ]]; then
+            skip_next=true
+            continue
+          fi
+
+          # Skip other flags
+          if [[ "$arg" =~ ^- ]]; then
+            continue
+          fi
+
+          # This should be the target
+          target="$arg"
+          break
+        done
+
+        echo "$target"
+      }
+
+      # Check if host has terminfo installed
+      _ghostty_host_has_terminfo() {
+        local target="$1"
+        [[ -f "$_ghostty_cache_file" ]] && grep -qFx "$target" "$_ghostty_cache_file" 2>/dev/null
+      }
+
+      # Add host to terminfo cache
+      _ghostty_cache_host() {
+        local target="$1"
+        local cache_dir
+        cache_dir="$(dirname "$_ghostty_cache_file")"
+
+        # Create cache directory if needed
+        [[ ! -d "$cache_dir" ]] && mkdir -p "$cache_dir"
+
+        # Atomic write to cache file
+        {
+          if [[ -f "$_ghostty_cache_file" ]]; then
+            cat "$_ghostty_cache_file"
+          fi
+          echo "$target"
+        } | sort -u > "$_ghostty_cache_file.tmp" && mv "$_ghostty_cache_file.tmp" "$_ghostty_cache_file"
+
+        # Secure permissions
+        chmod 600 "$_ghostty_cache_file" 2>/dev/null
+      }
+
       # Wrap `ssh` command to provide Ghostty SSH integration
       ssh() {
         case "$GHOSTTY_SSH_INTEGRATION" in
@@ -296,27 +356,41 @@ _ghostty_deferred_init() {
 
       # Level: full - All features
       _ghostty_ssh_full() {
-        # Full integration: Two-step terminfo installation
+        local target
+        target="$(_ghostty_get_ssh_target "$@")"
+
+        # Check if we already know this host has terminfo
+        if [[ -n "$target" ]] && _ghostty_host_has_terminfo "$target"; then
+          # Direct connection with xterm-ghostty
+          local env_vars=("TERM=xterm-ghostty")
+          [[ -n "$GHOSTTY_SHELL_FEATURES" ]] && env_vars+=("GHOSTTY_SHELL_FEATURES=$GHOSTTY_SHELL_FEATURES")
+          env "${env_vars[@]}" ssh "$@"
+          return 0
+        fi
+
+        # Full integration: Install terminfo if needed
         if builtin command -v infocmp >/dev/null 2>&1; then
-          echo "Installing Ghostty terminfo on remote host..." >&2
-          
-          # Step 1: Install terminfo
-          if infocmp -x xterm-ghostty 2>/dev/null | builtin command ssh "$@" 'tic -x - 2>/dev/null'; then
-            echo "Terminfo installed successfully. Connecting with full Ghostty support..." >&2
-            
-            # Step 2: Connect with xterm-ghostty since we know terminfo is now available
+          # Install terminfo only if needed
+          if infocmp -x xterm-ghostty 2>/dev/null | builtin command ssh "$@" '
+              if ! infocmp xterm-ghostty >/dev/null 2>&1; then
+                  echo "Installing Ghostty terminfo..." >&2
+                  tic -x - 2>/dev/null
+              fi
+          '; then
+            echo "Connecting with full Ghostty support..." >&2
+
+            # Cache this host for future connections
+            [[ -n "$target" ]] && _ghostty_cache_host "$target"
+
+            # Connect with xterm-ghostty since terminfo is available
             local env_vars=("TERM=xterm-ghostty")
-            
-            # Propagate Ghostty shell integration environment variables
             [[ -n "$GHOSTTY_SHELL_FEATURES" ]] && env_vars+=("GHOSTTY_SHELL_FEATURES=$GHOSTTY_SHELL_FEATURES")
-            
-            # Normal SSH connection with Ghostty terminfo available
             env "${env_vars[@]}" ssh "$@"
             builtin return 0
           fi
           echo "Terminfo installation failed. Using basic integration." >&2
         fi
-        
+
         # Fallback to basic integration
         _ghostty_ssh_basic "$@"
       }