DRIVERS-3082: Summary of necessary driver changes Update libmongocrypt bindings to pass all listCollection results in the MONGOCRYPT_CTX_NEED_MONGO_COLLINFO(_WITH_DB) states. Call mongocrypt_setopt_enable_multiple_collinfo to indicate the new behavior is implemented. Implement prose tests from https://github.com/mongodb/specifications/pull/1757 . libmongocrypt binding changes libmongocrypt's protocol previously assumed auto encrypting a command only required at most one schema. With $lookup there can be multiple schemas on an aggregate command. As a result, a small driver change is needed: feed all listCollections results to libmongocrypt in the MONGOCRYPT_CTX_NEED_MONGO_COLLINFO(_WITH_DB) states. The previous protocol only required returning the first. Call mongocrypt_setopt_enable_multiple_collinfo to indicate the new behavior is implemented (otherwise libmongocrypt returns an error if a command requires multiple schemas). The libmongocrypt documentation describes the updated protocol in integrating.md . See the small protocol change implemented in the C driver here . References libmongocrypt commit: 33fdf65 Specifications prose tests: PR#1757 C driver implementation: PR#1880