Expand description
Opaque cursor pagination helpers for MCP tool responses.
Implements the cursor conventions described in the MCP specification
(cursor / nextCursor, opaque tokens, JSON-RPC -32602 on invalid
input). Cursors are base64url-encoded JSON objects of the form
{"offset": <offset>}. The encoding is an implementation detail —
clients MUST treat cursors as opaque strings.
Tool requests declare their cursor as Option<Cursor>; the custom
Serialize/Deserialize impls encode to / decode from the base64url
wire string, so handlers never see the raw cursor string. Decode
errors surface as serde errors, which rmcp automatically maps to
JSON-RPC code -32602 when parsing tool arguments.