pms-ui-response is one of the internal packages that make up the pty-mcp-server project.
It is responsible for defining structured data types and utilities for formatting responses to be sent to the user interface layer.

In the context of a stdio-mode MCP server, this package specifically handles the construction and serialization of JSON-RPC response objects to be written to stdout.
It acts as the final output stage, transforming typed results from the application layer into well-structured JSON responses.