Short term work permits for the EU
Third-country nationals coming to the Schengen area to undertake a short term, time-specified work contract either for a company in the Schengen area, or to fulfil a contract of a company from a third-country, must obtain a short term work permit.
A short-term work permit allows the holder to remain in the Schengen Area for up to 90-days to undertake necessary work assignments. If the assignment and length of stay exceed 90 days, then the worker must obtain a long-stay Category D Visa.
It is the duty of your employer in the Schengen Area, or the Schengen Area company that is benefitting from the contract work, to apply for a pre-authorised work permit in the host country. Once the work permit is issued, this can be used to obtain the relevant visa in your country of origin.