GTFS RT PHP

GTFS-Realtime library for PHP 8.4+ based on Google's Protocol Buffers v5.

A modern PHP implementation of the GTFS Realtime specification. The proto definition was downloaded from gtfs.org and converted to proto3 syntax for compatibility with the latest google/protobuf PHP library.

Requirements

• PHP >= 8.4
• google/protobuf ^5.34

Installation

composer require dacoto/gtfs-rt-php

Usage

Creating a Feed Message

use Google\Transit\Realtime\FeedMessage;
use Google\Transit\Realtime\FeedHeader;
use Google\Transit\Realtime\FeedHeader\Incrementality;
use Google\Transit\Realtime\FeedEntity;
use Google\Transit\Realtime\TripUpdate;
use Google\Transit\Realtime\TripUpdate\StopTimeUpdate;
use Google\Transit\Realtime\TripUpdate\StopTimeEvent;
use Google\Transit\Realtime\TripDescriptor;

$feedMessage = new FeedMessage();

$header = new FeedHeader();
$header->setGtfsRealtimeVersion('2.0');
$header->setIncrementality(Incrementality::FULL_DATASET);
$header->setTimestamp(time());
$feedMessage->setHeader($header);

$entity = new FeedEntity();
$entity->setId('entity-1');

$tripDescriptor = new TripDescriptor();
$tripDescriptor->setTripId('trip-123');
$tripDescriptor->setRouteId('route-42');

$arrivalEvent = new StopTimeEvent();
$arrivalEvent->setDelay(120); // 2 minutes late

$stopTimeUpdate = new StopTimeUpdate();
$stopTimeUpdate->setStopSequence(1);
$stopTimeUpdate->setStopId('stop-A');
$stopTimeUpdate->setArrival($arrivalEvent);

$tripUpdate = new TripUpdate();
$tripUpdate->setTrip($tripDescriptor);
$tripUpdate->setStopTimeUpdate([$stopTimeUpdate]);

$entity->setTripUpdate($tripUpdate);
$feedMessage->setEntity([$entity]);

// Serialize to binary protobuf
$binaryData = $feedMessage->serializeToString();

Parsing a Feed Message

use Google\Transit\Realtime\FeedMessage;

$binaryData = file_get_contents('https://your-agency.com/gtfs-rt/tripupdates.pb');

$feedMessage = new FeedMessage();
$feedMessage->mergeFromString($binaryData);

echo "GTFS-RT version: " . $feedMessage->getHeader()->getGtfsRealtimeVersion() . PHP_EOL;

foreach ($feedMessage->getEntity() as $entity) {
    if ($entity->hasTripUpdate()) {
        $tripUpdate = $entity->getTripUpdate();
        echo "Trip ID: " . $tripUpdate->getTrip()->getTripId() . PHP_EOL;

        foreach ($tripUpdate->getStopTimeUpdate() as $stu) {
            if ($stu->hasArrival()) {
                echo "  Stop " . $stu->getStopId() . " delay: " . $stu->getArrival()->getDelay() . "s" . PHP_EOL;
            }
        }
    }
}

See full examples in the examples/ directory.

Proto3 Conversion Notes

The official GTFS Realtime proto uses proto2 syntax. This library converts it to proto3 to be compatible with the latest google/protobuf PHP library. The key changes are:

1. Changed syntax = "proto2" to syntax = "proto3"
2. Removed all optional and required field labels (all fields are optional in proto3)
3. Removed all extensions ranges (not supported in proto3)
4. Removed all explicit [default = ...] values
5. Added UNKNOWN_CAUSE = 0, NO_SERVICE = 0, and UNKNOWN_SEVERITY = 0 as first enum values (proto3 requires first value to be 0)
6. Added PHP namespace options: php_namespace and php_metadata_namespace

Running Tests

composer install
vendor/bin/phpunit

Regenerating PHP Classes

The PHP classes in src/ are generated automatically from gtfs-realtime.proto using protoc.

Automatic (GitHub Actions)

Every time composer.json or gtfs-realtime.proto is changed on main, the Regenerate PHP Classes workflow runs automatically, downloads the correct protoc binary, regenerates all PHP classes, and commits the result.

You can also trigger it manually from the Actions tab, optionally overriding the protoc version.

Manual (local)

Run the generation script — it resolves the protoc version from composer.json (or composer.lock) automatically:

bash bin/generate.sh

Or override the protoc version explicitly:

bash bin/generate.sh --protoc-version 34.1

The script:

1. Reads the google/protobuf version from composer.lock (or composer.json)
2. Derives the matching protoc release (e.g. PHP v5.34.1 → protoc v34.1)
3. Downloads the protoc binary from github.com/protocolbuffers/protobuf
4. Regenerates all PHP classes in src/ from gtfs-realtime.proto

License

MIT — See LICENSE