What does an npm publish error 400 Bad Request PUT typically indicate?

An npm publish error 400 Bad Request PUT usually signifies that the package.json file contains invalid or malformed data. This can include issues with dependencies, versioning, package name conflicts, or other inconsistencies that violate npm's publishing requirements. The PUT method indicates that npm is attempting to update the package information on the registry, and the 400 error means the server rejected the request due to the invalid data.