You can stitch multiple APIs together using GraphQL schema stitching, allowing for unified and transparent access to data from different sources without knowing the specific API endpoint. By creating a stitching proxy, you can combine schemas from remote APIs and merge them into a single schema with references between objects. This enables querying across APIs seamlessly, even when data is not directly available in the format needed or has conflicts due to duplicate types. With GraphQL schema stitching, you can also infer new data, expand existing fields, and leverage relationships between APIs to make data more accessible to developers.