  Interacting dark energy (IDE) scenario is a natural and important extension
to the standard $\Lambda$CDM cosmology. We develop a full numerical routine,
called IDECAMB, as a patch to the public Einstein-Boltzmann solver CAMB, to
solve the background and perturbation equations of the IDE models. The IDECAMB
solver provides a unified interface for the widely studied IDE models by
employing a parametrization model with five free functions. By configuring
these five functions, one can easily map the coupled quintessence (CQ) and
coupled fluid (CF) models into the parametrization. We handle the perturbation
evolutions of the CF models with the parametrized post-Friedmann (PPF) approach
to avoid the possible large-scale instability. Compared with the previous
established PPF approach whose form depends on a specific IDE model, the PPF
approach in this work are model-independent, making it easy to use. We
constrain a specific CQ model with the IDECAMB package. The fitting results are
consistent with those obtained by Planck Collaboration, which confirms the
validity of the package.
