Acquisition Surface: decision brief (GWP-709)

rule. Recorded in ADR-0057; spec skeleton at ../programs/deck-hub-supply.md. This brief is the option analysis behind that pick, and the gate doc for the shop-home section of the Deck Hub spec (GWP-710). Date: 2026-07-17 Companions: economy-model.md (the acquisition loop this surfaces), catalog-taxonomy.md (GWP-712: classes, stable IDs, exposure stages), ADR-0056 (the ownership ledger purchases deposit into), ADR-0055 (engine-priced awards; wallet writes are System-tier), ADR-0042 (the closed thirteen-program roster).

1. The decision

The economy model’s acquisition loop ends in two designed moments that have no surface today:

Expose. On debrief, a missing verb, program, or equipment item appears with a price. Debrief fires as a CIPHER-LINE beat on the OLED (ADR-0015); there is no main-grid debrief modal. An OLED line is ephemeral, so the advert needs a persistent place where the exposed item sits with its price.
Buy. Somewhere the operator browses exposed items (the sims model ~135 catalog entries across six classes) and converts credits into ownership via ownership_commit.

This brief decides which surface owns viewing and buying, and rules on when the mission board may regenerate after a purchase (§4). Everything else is already fixed by the companions: the loop shape, the taxonomy, the exposure-stage schema, the ledger, and the pricing authority.

2. The exposure moment (common to every option)

Shared plumbing, identical under all four options:

Mission resolution settles the award (ADR-0055), then the exposure ledger flips the taught item hidden -> exposed (GWP-712 §3; run-state, regenerable).
CIPHER emits the advert on the OLED during the :debrief beat (a new :catalog-exposed event type; copy per the CIPHER style guide).
The exposed item is now listed, with a price, on the chosen surface. Row 0 / Row 74 remain firmware-owned; any “new stock” affordance rides the chosen surface’s own rows.

The decision is only where that listing lives.

3. Options

A. Deck Hub SUPPLY view (shop home inside program #2)

Deck Hub gains one view beside the character sheet and the loadout: the catalog of exposed items, priced; EVAL on an item spends and commits. The bench (“what I own”) extends into “what is on offer,” the seam the GWP-710 spec already reserves.

For: No roster change. Purchase-to-equip adjacency: buy a verb-tool, slot it, all in one program. The wallet readout the shop spends against already lives here. Bare-deck available.
Against: Weakest fiction (a store tab in a character screen reads as game furniture unless dressed as a procurement channel). Deck Hub accretes a fourth job (state, loadout, onboarding, now commerce). The advert and the store are two hops apart: debrief happens at the board/OLED, buying happens in Deck Hub.

B. Board debrief overlay (shop moment inside program #1)

Mission resolution returns to the board through a DEBRIEF panel (the ADR-0050 PEEK pattern: a docked right-hand panel over the feed) showing the settled award plus the newly exposed items; EVAL buys from the panel. A full catalog list would live behind a board tab.

For: Tightest teach-by-need loop: the struggle, the advert, and the purchase land on one screen at the moment of pain. Gives the settlement math (ADR-0055 banked rewards, escrow) a main-grid home too.
Against: Scope-creeps the Mission Board from work discovery into commerce. An overlay cannot carry ~135-item browsing, so a full catalog home is still needed somewhere, which risks two shop surfaces. Sharpest regen coupling: buying happens on the surface that regenerates (§4 stops being optional here).

C. kn9 vendor thread (diegetic fence)

A :vendor folder in kn9. Exposure arrives as an offer message on the World Engine feed after debrief; replying to the offer buys.

For: Maximum diegesis. The fence, the dead drop, the offer that arrives: all native to kn9’s feed model, and the arrival timing IS the exposure moment.
Against: kn9’s charter excludes economy ownership, and v1 compose is read-mostly by design. Browsing and comparing a six-class catalog through mail threads is poor UX at ~135 items. The bare-deck inbox fattens with engine-authored commerce traffic.

D. New dedicated program (fourteenth roster entry)

A purpose-built shop program (working name GRAYMARKET), chartered by amending ADR-0042.

For: Clean scope; a tabulated-list catalog is exactly the shared feed-reader shape (kn9 / Mission Board lineage), so construction reuse is high. Room to grow the fence fiction without bending another program’s charter.
Against: Costs the roster amendment ADR-0042 exists to make expensive. Overlaps Deck Hub’s bench and wallet. A fourteenth router tile for a surface visited between missions.

Trade-off table

Dimension	A. Deck Hub view	B. Board overlay	C. kn9 thread	D. New program
Roster cost (ADR-0042)	none	none	none	amendment
Teach -> buy adjacency	two hops	same screen	feed arrival	two hops
Catalog browsing at ~135 items	good (list view)	poor (overlay)	poor (threads)	good
Fiction / diegesis	weak unless dressed	medium	strongest	strong
Construction reuse	tabulated-list	ADR-0050 peek	kn9 feed	tabulated-list
Host-program scope pressure	high (4th job)	high (commerce on the board)	high (charter conflict)	none (new charter)
Purchase-to-equip adjacency	best (bench beside shop)	none	none	none
Board regen coupling (§4)	low	highest	low	low
Spec/eng surface touched	deck-hub.md (GWP-710 seam)	board + ADR-0050	kn9.md + feed	new charter + spec + router

Recommendation (picked by Josh, 2026-07-17)

A, with C as the flavor channel later. Deck Hub owns viewing and buying (the GWP-710 seam snaps in with no rework); the advert is the CIPHER :catalog-exposed debrief line; a cart may later enrich the moment with a kn9 handler message pointing at the same SUPPLY entry (enrich-never-gate, no purchase mechanics in kn9). Option B’s adjacency is real but buys it by making the board a store; if the two-hop distance proves a felt problem on glass, a Row-74 affordance from the board to Deck Hub SUPPLY closes it without moving the shop.

4. The regen rule (ruled here, recorded in ADR-0057)

Today mission_board.c subscribes its regenerate-on-next-peek dirty flag to six events, including NOSH_EVENT_UDS_CREDIT_CHANGED (mission_board.c:139). Purchases will publish that event through the GWP-718 evented setters. Two failures follow:

Feel. Buy at the debrief, return to the board, and the board you were just reading has re-minted: same seed, but instance count and payouts shift with balance_tier.
Probe. broke_bonus grants +25% payouts below the broke threshold at generation time. Spending down to the threshold (a cheap consumable) and re-entering the board reprices every contract upward. Shopping becomes a payout lever.

Rule: a purchase never regenerates or reprices the board. The board’s dirty flag drops its UDS_CREDIT_CHANGED subscription entirely; regeneration triggers are mission resolution (completed / failed / abandoned), cart-history change, reputation change, and cipher-seed advance. balance_tier and broke_bonus are therefore evaluated only at those boundaries, which restores their design intent: relief for an operator left broke by play. Shopping stops touching the payout math. Ownership-driven eligibility (fixed rule 3: buying a program or verb widens which templates compose) lands at the same boundaries; the next board after the next resolution shows the new work, and the debrief advert can say so.

Rejected alternative: pinning displayed contracts while refilling vacancies (a feed-native incremental board). Better long-term model, but it is a board redesign, out of GWP-709’s scope, and ADR-0055’s accepted-snapshot rule already protects the one contract where repricing draws blood.

5. What follows the pick

ADR-0057 records the owner and the regen rule (amending ADR-0042 only if D).
Spec skeleton for the chosen surface lands beside this brief (or inside deck-hub.md if A, through the GWP-710 seam).
Engineering follow-ons: the :catalog-exposed CIPHER event; the purchase path (ownership_commit + evented spend); the mission_board.c subscription change.