This is a precedent application programming interface (API) licence agreement, which is intended for use when the licensor of an online platform grants the developer of a certain application rights to use the API to interface between a platform and the application in a business to business context. This API licence agreement should be used when a more bespoke, negotiated agreement is to be entered into between the licensor and licensee, rather than the licensor simply displaying its API terms of use on its website and making the API freely available for use subject to those terms, as commonly happens. It is drafted mainly from the point of view of the licensor but includes some drafting suggestions for alternative clauses to make the agreement more balanced, which you may wish to include if you are acting for the licensee.