According to The New York Times, Twitter's lawyer Alex Spiro

wrote a letter to Microsoft CEO Satya Nadella on behalf of Twitter

accusing Microsoft of breaking Twitter's developer agreement.

Up until recently, Microsoft had integrated Twitter's APIs with some of its products.

Twitter's letter claims Microsoft operated "eight separate Twitter API apps" integrated

with products like Xbox, Bing, and its ads platform.

Spiro claims that Microsoft may have been in violation of "multiple provisions".