Python library for managing MOS running orders. Pronounced mos-ro-manager.


The library provides functionality for classifying MOS file types, processing and inspecting MOS message files, as well as merging MOS files into a running order, and providing a “completed” programme including all additions and changes made between the first message (roCreate) and the last (roDelete).

This can be used as a library, using the utilities provided in the mosromgr module, and the command line command CLI can be used to process either a directory of MOS files, or a folder within an S3 bucket.

This library was developed by the BBC News Labs team.


Note that the library is currently in beta. The API and CLI are not yet stable and may change. Once the library reaches v1.0, it will be considered stable. Please consider giving Feedback to help stabilise the API.

Example Usage

Command line

List the stories within a running order:

$ mosromgr inspect -f roCreate.mos.xml --stories
0828 MIDLANDS TODAY Wed, 11.11.2020





Merge all MOS files in directory newsnight and save in FINAL.xml:

$ mosromgr merge -f newsnight/* -o FINAL.xml


Load a roCreate file and view its stories:

from mosromgr.mostypes import RunningOrder

ro = RunningOrder.from_file('roCreate.mos.xml')

for story in ro.stories:

Merge a single roStorySend (StorySend) into a roCreate (RunningOrder) and output the file to a new file:

from mosromgr.mostypes import RunningOrder, StorySend

ro = RunningOrder.from_file('roCreate.mos.xml')
ss = StorySend.from_file('roStorySend.mos.xml')

ro += ss

with open('final.mos.xml', 'w') as f:

If you’re automating this process you won’t necessarily know which MOS Type to use, so you can construct an object from the base class MosFile which will automatically classify your file:

>>> from mosromgr.mostypes import MosFile
>>> mf1 = MosFile.from_file('roCreate.mos.xml')
>>> mf1
<RunningOrder 1000>
>>> mf2 = MosFile.from_file('roStorySend.mos.xml')
>>> mf2
<StorySend 1001>

Using MosCollection will sort and classify multiple MOS types of all given files, allowing you to process a collection of MOS files within a complete or partially complete programme:

from mosromgr.moscollection import MosCollection

mos_files = ['roCreate.mos.xml', 'roStorySend.mos.xml', 'roDelete.mos.xml']
mc = MosCollection.from_files(mos_files)

with open('final.mos.xml', 'w') as f:


This documentation follows the Diátaxis system, so is split between four modes of documentation: tutorials, how-to guides, technical reference and explanation.

Indices and tables

Issues and questions

Questions can be asked on the discussion board, and issues can be raised on the issue tracker.


Source code can be found on GitHub at

Contributions are welcome. Please refer to the contributing guidelines.



Licensed under the Apache License, Version 2.0.


To get in touch with the maintainers, please contact the BBC News Labs team: