Setting the file. One moment.
EXAMPLE Php · Instrument Product Analytics · PostHog/skills · Skills Docs
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A simple command-line todo application built with plain PHP (no framework) demonstrating PostHog integration for CLIs, scripts, data pipelines, and non-web PHP applications.
Verification that the context-mill wizard works for plain PHP projectsReference implementation of PostHog best practices for non-framework PHP codeWorking example you can run and modify
SDK initialization - Uses PostHog::init(...) once with environment-based configurationEvent tracking - Captures user actions with distinctId and propertiesUser identification - Associates properties with users via PostHog::identify(...)Error tracking - Enables automatic PHP error tracking and manually captures handled exceptionsProper flushing - Calls PostHog::flush() before CLI exit The app tracks these events in PostHog:
The app works fine without PostHog configured - it simply won’t track analytics. You’ll see a warning message but the app continues to function normally.
Modify todo.php to experiment with PostHog tracking
Add new commands and track their usage
Explore feature flags: PostHog::isFeatureEnabled('flag-name', 'user_id')
Check your PostHog dashboard to see tracked events
references/EXAMPLE-php.md
if ( ! file_exists ($path)) {
return ;
}
foreach ( file ($path, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES ) ?: [] as $line) {
$line = trim ($line);
if ($line === '' || str_starts_with ($line, '#' ) || ! str_contains ($line, '=' )) {
continue ;
}
[$key, $value] = explode ( '=' , $line, 2 );
$key = trim ($key);
$value = trim ($value, " \t\n\r\0\x0B\" '" );
if ($key !== '' && getenv ($key) === false ) {
putenv ($key . '=' . $value);
$_ENV[$key] = $value;
}
}
}
function dataFilePath () : string
{
$home = getenv ( 'HOME' ) ?: sys_get_temp_dir ();
return rtrim ($home, DIRECTORY_SEPARATOR ) . DIRECTORY_SEPARATOR . DATA_FILE ;
}
function initializePostHog () : bool
{
loadEnvFile ( __DIR__ . '/.env' );
$projectToken = getenv ( 'POSTHOG_PROJECT_TOKEN' );
if ( ! $projectToken || str_starts_with ($projectToken, 'phc_your_' )) {
echo "WARNING: PostHog not configured (POSTHOG_PROJECT_TOKEN not set) \n " ;
echo " App will work but analytics won't be tracked \n " ;
return false ;
}
PostHog :: init ($projectToken, [
'host' => getenv ( 'POSTHOG_HOST' ) ?: 'https://us.i.posthog.com' ,
'error_tracking' => [
'enabled' => true ,
'context_provider' => static function ( array $payload) : array {
return [
'distinctId' => getUserId (),
'properties' => [
'app' => 'php_todo_cli' ,
'runtime' => PHP_VERSION ,
'$exception_source' => $payload[ 'source' ] ?? null ,
],
];
},
],
]);
return true ;
}
function getUserId () : string
{
$path = dataFilePath ();
if ( file_exists ($path)) {
$data = json_decode (( string ) file_get_contents ($path), true );
if ( is_array ($data) && isset ($data[ 'user_id' ])) {
return ( string ) $data[ 'user_id' ];
}
}
return 'user_' . bin2hex ( random_bytes ( 4 ));
}
function loadTodos () : array
{
$path = dataFilePath ();
if ( ! file_exists ($path)) {
return [ 'user_id' => getUserId (), 'todos' => []];
}
$data = json_decode (( string ) file_get_contents ($path), true );
if ( ! is_array ($data)) {
return [ 'user_id' => getUserId (), 'todos' => []];
}
$data[ 'todos' ] = $data[ 'todos' ] ?? [];
$data[ 'user_id' ] = $data[ 'user_id' ] ?? getUserId ();
return $data;
}
function saveTodos ( array $data) : void
{
file_put_contents ( dataFilePath (), json_encode ($data, JSON_PRETTY_PRINT ) . PHP_EOL );
}
function identifyUser ( bool $posthogEnabled) : void
{
if ( ! $posthogEnabled) {
return ;
}
PostHog :: identify ([
'distinctId' => getUserId (),
'properties' => [
'app_language' => 'php' ,
'app_type' => 'cli' ,
],
]);
}
function trackEvent ( bool $posthogEnabled, string $eventName, array $properties = []) : void
{
if ( ! $posthogEnabled) {
return ;
}
PostHog :: capture ([
'distinctId' => getUserId (),
'event' => $eventName,
'properties' => $properties,
]);
}
function cmdAdd ( string $text, bool $posthogEnabled) : void
{
$data = loadTodos ();
$todo = [
'id' => count ($data[ 'todos' ]) + 1 ,
'text' => $text,
'completed' => false ,
'created_at' => date ( DATE_ATOM ),
];
$data[ 'todos' ][] = $todo;
saveTodos ($data);
echo "Added todo #{ $todo ['id']}: { $todo ['text']} \n " ;
trackEvent ($posthogEnabled, 'todo_added' , [
'todo_id' => $todo[ 'id' ],
'todo_length' => strlen ($todo[ 'text' ]),
'total_todos' => count ($data[ 'todos' ]),
]);
}
function cmdList ( bool $posthogEnabled) : void
{
$data = loadTodos ();
if ( count ($data[ 'todos' ]) === 0 ) {
echo "No todos yet! Add one with: php todo.php add 'Your task' \n " ;
return ;
}
echo " \n Your Todos (" . count ($data[ 'todos' ]) . " total): \n\n " ;
foreach ($data[ 'todos' ] as $todo) {
$status = $todo[ 'completed' ] ? 'X' : ' ' ;
echo " [{ $status }] #{ $todo ['id']}: { $todo ['text']} \n " ;
}
echo " \n " ;
trackEvent ($posthogEnabled, 'todos_viewed' , [
'total_todos' => count ($data[ 'todos' ]),
'completed_todos' => count ( array_filter ($data[ 'todos' ], static fn ( array $todo) : bool => ( bool ) $todo[ 'completed' ])),
]);
}
function cmdComplete ( int $id, bool $posthogEnabled) : void
{
$data = loadTodos ();
foreach ($data[ 'todos' ] as & $todo) {
if (( int ) $todo[ 'id' ] !== $id) {
continue ;
}
if ($todo[ 'completed' ]) {
echo "Todo #{ $id } is already completed \n " ;
return ;
}
$todo[ 'completed' ] = true ;
$todo[ 'completed_at' ] = date ( DATE_ATOM );
saveTodos ($data);
echo "Completed todo #{ $todo ['id']}: { $todo ['text']} \n " ;
$timeToComplete = ( strtotime ($todo[ 'completed_at' ]) - strtotime ($todo[ 'created_at' ])) / 3600 ;
trackEvent ($posthogEnabled, 'todo_completed' , [
'todo_id' => $todo[ 'id' ],
'time_to_complete_hours' => $timeToComplete,
]);
return ;
}
echo "ERROR: Todo #{ $id } not found \n " ;
}
function cmdDelete ( int $id, bool $posthogEnabled) : void
{
$data = loadTodos ();
foreach ($data[ 'todos' ] as $index => $todo) {
if (( int ) $todo[ 'id' ] !== $id) {
continue ;
}
unset ($data[ 'todos' ][$index]);
$data[ 'todos' ] = array_values ($data[ 'todos' ]);
saveTodos ($data);
echo "Deleted todo #{ $id } \n " ;
trackEvent ($posthogEnabled, 'todo_deleted' , [
'todo_id' => $todo[ 'id' ],
'was_completed' => $todo[ 'completed' ],
]);
return ;
}
echo "ERROR: Todo #{ $id } not found \n " ;
}
function cmdStats ( bool $posthogEnabled) : void
{
$data = loadTodos ();
$total = count ($data[ 'todos' ]);
$completed = count ( array_filter ($data[ 'todos' ], static fn ( array $todo) : bool => ( bool ) $todo[ 'completed' ]));
$pending = $total - $completed;
$rate = $total > 0 ? number_format ($completed / $total * 100 , 1 ) : '0.0' ;
echo " \n Stats: \n\n " ;
echo " Total todos: { $total } \n " ;
echo " Completed: { $completed } \n " ;
echo " Pending: { $pending } \n " ;
echo " Completion rate: { $rate }% \n\n " ;
trackEvent ($posthogEnabled, 'stats_viewed' , [
'total_todos' => $total,
'completed_todos' => $completed,
'pending_todos' => $pending,
]);
}
function printUsage () : void
{
echo <<< USAGE
Simple todo app with PostHog analytics
Usage:
php todo.php add "Todo text" Add a new todo
php todo.php list List all todos
php todo.php complete <id> Mark todo as completed
php todo.php delete <id> Delete a todo
php todo.php stats Show statistics
USAGE ;
}
$posthogEnabled = false ;
try {
$posthogEnabled = initializePostHog ();
identifyUser ($posthogEnabled);
$command = $argv[ 1 ] ?? null ;
if ( ! $command) {
printUsage ();
exit ( 0 );
}
switch ($command) {
case 'add' :
$text = $argv[ 2 ] ?? null ;
if ( ! $text) {
echo "ERROR: Please provide todo text \n " ;
echo "Usage: php todo.php add \" Your task \"\n " ;
exit ( 1 );
}
cmdAdd ($text, $posthogEnabled);
break ;
case 'list' :
cmdList ($posthogEnabled);
break ;
case 'complete' :
$id = ( int ) ($argv[ 2 ] ?? 0 );
if ($id <= 0 ) {
echo "ERROR: Please provide a valid todo ID \n " ;
echo "Usage: php todo.php complete <id> \n " ;
exit ( 1 );
}
cmdComplete ($id, $posthogEnabled);
break ;
case 'delete' :
$id = ( int ) ($argv[ 2 ] ?? 0 );
if ($id <= 0 ) {
echo "ERROR: Please provide a valid todo ID \n " ;
echo "Usage: php todo.php delete <id> \n " ;
exit ( 1 );
}
cmdDelete ($id, $posthogEnabled);
break ;
case 'stats' :
cmdStats ($posthogEnabled);
break ;
default :
echo "ERROR: Unknown command '{ $command }' \n " ;
printUsage ();
exit ( 1 );
}
} catch ( Throwable $e) {
echo "ERROR: { $e -> getMessage ()} \n " ;
if ($posthogEnabled) {
PostHog :: captureException ($e, getUserId (), [
'command' => $argv[ 1 ] ?? null ,
'app' => 'php_todo_cli' ,
]);
}
exit ( 1 );
} finally {
if ($posthogEnabled) {
PostHog :: flush ();
}
}