A Canon receipt binds a formula, its version, the inputs and the outputs into one hash. Paste a receipt below, or open a share link, and the server recomputes it from the inputs. If anything was edited after the fact, it says so and shows the true outputs.
Share links carry the receipt in the URL fragment; nothing is stored on the server. Add the MCP endpoint to Claude, Claude Code or Cursor and the canon_verify tool does the same check inside the agent.