This library is designed to access the binary planetary ephemeris files, such INPOPxx, JPL DExxx and SPICE ephemeris files.

This library provides a C Application Programming Interface (API) and, optionally, Fortran 77/2003, Python 2/3 and octave/Matlab interfaces to be called by the application.


This software is an open-source product distributed under three distinct licenses giving you the choice of one of the three following sets of free software/open source licensing terms. This allows the use of our code in as wide a variety of software projects as possible.

This software is governed by the CECILL-C, CECILL-B or CECILL version 2.1 license under French law and abiding by the rules of distribution of free software. You can use, modify and/or redistribute the software under the terms of the CeCILL-C, CeCILL-B or CeCILL license as circulated by CEA, CNRS and INRIA at the following URL


Latest stable version

  • Version 3.5.2 (March 2023)
    PyPI version
    Homebrew version Vcpkg package
    Fedora package ConanCenter package
    Octave package
    • Fix a possible buffer overflow in the python interface of getfileversion.
    • Fix the undefined external symbol rint with visual C compiler 10.0.
    • Fix the redefinition of vasprintf with the environnment MinGW.
  • Previous releases

Development version

The latest sources of the library are available using this gitlab repository.


Reference manuals


External tutorials are available for various languages.

  • Python interface
  • Octave/Matlab interface


The installation steps for various programming languages are described in the following links.

Other interfaces

The following interfaces for CALCEPH are available:


The library is written by the research team Astronomie et systèmes dynamiques (CNRS/Observatoire de Paris/IMCCE).

For all comments concerning these pages, contact the authors:

Last update Wednesday 12 April 2023