A second board behind the provider protocol

Status: accepted · 2026-09-25 (proposed 2026-09-04)

Accepted because stage 0 of Phase 3 built the seam: --file-ticket now files through the board it is handed, and Linear is one board among two.

Context

The protocol was five methods, and --file-ticket and --update called Linear directly, so a second board meant a second filing path.

Decision

provider.Board is the seam. Beside the loop's members it has file(), update() and stored_body(): create a ticket, revise it, read back what the board stored. board_for() is the one place that builds a project's board, reading [board] kind (linear, the default; native refused until it ships); [board] mode (mirror or store) is accepted beside it. LinearBoard and FileProvider both implement it, and one conformance suite holds them alike. The rest of Phase 3 is the "boards and the store" design, §2 and §10.

Consequences

A new board is one class and one kind value; the loop and --file-ticket do not change. The exit-2 line still says "as stored by Linear" whatever the board; its wording waits for the native board.

Tickets

KO-730, KO-731, KO-732, KO-734.