README

An experimental, dependency-free-at-runtime PHP 8.1+ port of Swiss Ephemeris 2.10.03. It exposes both familiar swe_* functions and a typed object-oriented facade.

Pre-1.0 status: this repository is under active correctness work. CI is configured to check the self-contained regression suite, and the full local suite passes with the documented ephemeris fixture set. That still does not establish independent drop-in or bit-for-bit parity with the C library. See Compatibility status.

Why this project exists

Run calendar, house, sidereal and selected planetary calculations without a PHP extension or subprocess.
Keep a C-compatible function surface while offering a modern Swisseph\OO API.
Make numerical limitations visible and reproducible instead of hiding them behind coverage claims.
Publish a reproducible implementation and parity corpus that other language ports can reuse.

Installation

No stable Packagist release exists yet. Install the development branch directly from GitHub:

composer config repositories.php-swisseph vcs https://github.com/gutsergut/php-swisseph
composer require gutsergut/php-swisseph:dev-main

After the first stable tag is published to Packagist, the intended command is:

composer require gutsergut/php-swisseph:^0.1

Quick start

<?php

require __DIR__ . '/vendor/autoload.php';

use Swisseph\Constants;
use Swisseph\OO\Swisseph;

$swe = new Swisseph('/path/to/ephemeris/files');
$jd = $swe->julianDay(2000, 1, 1, 12.0);
$sun = $swe->planet(Constants::SE_SUN, $jd);

if ($sun->isError()) {
    throw new RuntimeException($sun->error ?? 'Calculation failed');
}

printf("Sun longitude: %.8f°\n", $sun->longitude);

$houses = $swe->houses($jd, 52.52, 13.405, 'P');
printf("Ascendant: %.8f°\n", $houses->ascendant);

The procedural API remains available:

$xx = [];
$error = null;
$flags = swe_calc_ut($jd, SE_SUN, SEFLG_SWIEPH | SEFLG_SPEED, $xx, $error);

Ephemeris data

Some calculations work from analytical Moshier/VSOP data shipped in this repository. Swiss Ephemeris .se1 files, JPL files and star catalogues are not bundled; configure their directory with swe_set_ephe_path() or the Swisseph constructor.

The active backend and returned flags matter. A successful call does not by itself prove that the requested backend was used. Consumers should retain flags, errors and backend metadata in their own result contract.

Development

composer install
composer check       # syntax, PHPStan (with explicit legacy baseline), CI regression suite
composer test:full   # diagnostic compatibility suite; requires external data for all checks

Set SWEPH_EPHE_DIR to a directory containing licensed ephemeris files when running file-backed tests:

SWEPH_EPHE_DIR=/opt/swisseph/ephe composer test:full

Read CONTRIBUTING.md before changing numerical code. A calculation fix needs a reference vector, provenance, tolerance and a regression test.

Project status and plans

Licensing and provenance

This derivative port is distributed under the GNU Affero General Public License v3.0 or later. Swiss Ephemeris is dual-licensed by Astrodienst AG; proprietary distribution may require its professional license. See LICENSE, NOTICE and license notes.

The name “Swiss Ephemeris” identifies the upstream project; this repository is an independent community port and is not endorsed by Astrodienst AG.

gutsergut / php-swisseph

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