Merge pull request 'feat(#58): trade & embargoes — economy layer (v0.35.0)' (#69) from feat/58-trade-embargo into master

AGENTS.md

@@ -56,7 +56,7 @@ history/
 ├── eslint.config.js        # flat config (ESLint 9)
 ├── tsconfig.json           # strict; aliases @/ → src/, @shared/ → shared/
 ├── vite.config.ts          # dev server + proxy /api,/sse → :4321; @ / @shared aliases
-├── vitest.config.ts        # unit tests (server/**/*.test.ts + scripts/**/*.test.ts; 225 tests)
+├── vitest.config.ts        # unit tests (server/**/*.test.ts + scripts/**/*.test.ts; 407 tests)
 ├── playwright.config.ts    # deterministic e2e (webServer runs npm run dev, LLM_STUB=1)
 ├── index.html
 ├── presets/                # 5 scenario JSON files + index.json (manifest)
@@ -378,6 +378,35 @@ history/
   user payload carries the player's `relations` map so the model can reason about the
   relation caps. The **stub never** proposes a hybrid op, so e2e (CI, `LLM_STUB=1`) is
   unaffected and the path is unit-tested only (`server/engine.test.ts`).
+- **Trade & embargo economy layer — `GameState.trades` / `GameState.embargoes`, `TurnResult.economy` (v0.35, #58).**
+  `TurnResult.economy = { trade: EconomyTradeOp[]; embargo: EconomyEmbargoOp[] }` (required;
+  default `{ trade: [], embargo: [] }`) is the model's lever for the economic layer: a
+  bilateral **trade** (`{ a, b, lift? }` — symmetric, stored **sorted** `a < b`) and a
+  unilateral **embargo** (`{ from, target, lift? }` — ordered). No `lift` declares/imposes,
+  `lift: true` ends/lifts (a no-op when absent). Refs are resolved at apply time by the
+  shared `resolveNationRef` (id first, then case-insensitive unique name); an unknown /
+  ambiguous / self-pairing op is dropped (never thrown). The lists live in `GameState`
+  (`trades`/`embargoes`, required, `[]` at creation; a legacy SQLite row without them loads
+  as `[]` — additive, never wiped, like `wars`/`markers`). **Deterministic, no hidden
+  randomness.** Every committed turn, in `applyTurnResult` (after hybrid, before markers):
+  (1) `applyEconomyOps` applies this turn's declares/lifts to the active lists (idempotent
+  declares — an already-active pair/ordered pair is not duplicated); (2)
+  `suspendEconomyOnWar` **auto-suspends** any trade or embargo whose two nations are on
+  opposite sides of an **active** `War` (#56) — a war severs the economic link, so the
+  suspended pair stops producing its effect (this also drops a trade declared this turn
+  between two nations that just went to war); (3) `applyEconomyEffects` applies the per-turn
+  effect to the **full** active lists: each active trade gives **both** parties a small,
+  deterministic `economy` gain (`TRADE_ECONOMY_BONUS`), each active embargo dips the
+  **target's** `economy` only (`EMBARGO_ECONOMY_PENALTY`) — clamped to 0–100, mirrored to
+  every region the nation owns (`regionStats`), and each affected nation's derived `stats`
+  re-derived afterwards (same 0-region / no-entry guards as the hybrid dip). Sole ownership
+  is untouched (the layer moves stats, never territory). `isMeaningful` counts non-empty
+  `economy.trade` / `economy.embargo`; the system prompt documents the field + constraints
+  (at most 1–2 ops per turn, narrated in `events`; warring pairs auto-suspended), and the
+  user payload carries the active `trades`/`embargoes` so the model can `lift` them. The
+  **stub never** declares or lifts a trade/embargo (`economy: { trade: [], embargo: [] }`),
+  so e2e (CI, `LLM_STUB=1`) is unaffected and the path is unit-tested only
+  (`server/engine.test.ts`).
 - **Map click → dossier target (owner resolved from the RegionMap, by region key).**
   Clicking a sub-region does NOT open a popup — it switches the dossier to that sub-region's
   owning nation (`focusNation(ownerId, {name})` in `App.tsx`, which also records which region was

CHANGELOG.md

@@ -2,6 +2,25 @@
 
 All notable changes to **History** are listed here, newest first.
 
+## v0.35.0 — 2026-10-15 17:22
+- **#58: Trade & Embargoes — a bilateral trade + embargo economy layer with a deterministic per-turn effect and war auto-suspension.** Every prior turn lever moved borders, dipped stats one-shot, or proposed a player-confirmed change. This version adds `TurnResult.economy = { trade: EconomyTradeOp[]; embargo: EconomyEmbargoOp[] }` (required, default `{ trade: [], embargo: [] }`) so the model can declare/lift **bilateral trade agreements** and **unilateral embargoes**, which persist in `GameState` and apply a small, deterministic economic effect **every committed turn**. The engine is **fully deterministic (no hidden randomness)** and **additive** — declares add to the lists, lifts remove, and nothing else (not even a war, beyond the suspension below) mutates them.
+  - **Types (`shared/types.ts`).** New `TradeAgreement` (`{ a; b }` — a symmetric pair, stored sorted `a < b`) and `Embargo` (`{ from; target }` — an ordered unilateral pair) interfaces, plus the required `GameState.trades` and `GameState.embargoes` fields (placed after `wars`). Both are `[]` on a fresh game; rows saved before v0.35 load with them defaulted to `[]` (additive, never wiped).
+  - **Protocol (`shared/protocol.ts`).** New `EconomyTradeOp` (`{ a; b; lift? }`), `EconomyEmbargoOp` (`{ from; target; lift? }`), and `EconomyOps` (`{ trade; embargo }`) types. `TurnResult.economy` is required, placed between `hybrid` and `markers`; a no-`lift` op declares/imposes, `lift: true` ends/lifts.
+  - **Engine (`server/engine.ts`).**
+    - `validateEconomyOps(raw)` — new exported, defensive validator (never throws): a missing/malformed object yields `{ trade: [], embargo: [] }`; each op needs non-empty `a`/`b` (or `from`/`target`) refs (trimmed, ≤200 chars) and a boolean `lift` (default false). Raw refs are kept — resolution happens at apply time against the real state (like wars/hybrid ops).
+    - `applyEconomyOps(next, ops)` — internal; resolves each op's refs via `resolveNationRef` (id first, then unique case-insensitive name). An unresolvable / ambiguous / self-pairing op is dropped (never thrown). A no-`lift` trade **declares** the agreement idempotently (stored sorted, so `{a,b}` and `{b,a}` are the same pair); `lift: true` ends it (a no-op when absent). A no-`lift` embargo **imposes** the ordered from→target pair idempotently; `lift: true` lifts it.
+    - `suspendEconomyOnWar(next)` — internal; any active trade or embargo whose two nations are on **opposite sides of an active war** (v0.33, #56) is removed — a war severs the economic link, so the suspended agreement stops producing its per-turn effect from now on. Runs **after** the turn's war declare/end ops (so it sees the final `next.wars`, including a war declared this turn) and **before** the per-turn effect.
+    - `applyEconomyEffects(next, geoOf?)` — internal; the per-turn effect, applied **every committed turn** to the **full** active lists (not just this turn's declares): each active trade grants **both** parties a small, deterministic economy gain (`TRADE_ECONOMY_BONUS`); each active embargo applies a small, deterministic economy dip to the **target only** (`EMBARGO_ECONOMY_PENALTY`). Clamped to 0–100, mirrored to every region the nation owns (`regionStats`), and each affected nation's derived `stats` re-derived afterwards (same 0-region/no-entry guards as the hybrid dip). No-op when there are no active trades or embargoes; never throws.
+    - `applyTurnResult` — new **economy block** (after the hybrid block, before markers): `applyEconomyOps` → `suspendEconomyOnWar` → `applyEconomyEffects`, in that order (ops first, so a same-turn trade declared between two nations that just went to war is suspended; effects then run on the surviving full lists). Sole ownership is untouched (the economy layer moves stats, never territory).
+    - `isMeaningful` — a non-empty `economy.trade` or `economy.embargo` makes a turn meaningful.
+    - `validateTurnResult` — initializes and validates `economy` (default `{ trade: [], embargo: [] }`).
+    - `buildSystemPrompt` — documents the `economy` field and a constraint bullet (bilateral trade gains both parties; a unilateral embargo hits the target only; omit `lift` to declare/impose, `lift: true` to end/lift; at most 1–2 ops per turn, narrated in `events`; trades/embargoes between warring nations are auto-suspended) in both tool and plain modes.
+    - `buildUserPrompt` — new optional `trades` and `embargoes` params (the currently active agreements/embargoes) so the model knows what is active and can `lift` it; emitted only when provided.
+    - `runTurn` — passes `state.trades` and `state.embargoes` to `buildUserPrompt`; the "unclear" fallback carries `economy: { trade: [], embargo: [] }`.
+  - **Stub (`server/stub.ts`).** The deterministic stub returns `economy: { trade: [], embargo: [] }` — it **never** declares or lifts a trade or embargo, so the e2e (CI, `LLM_STUB=1`) assertions are unaffected and the path is covered by unit tests only (`server/engine.test.ts`).
+  - **Persistence (`server/db.ts`).** `load()` defaults `trades`/`embargoes` to `[]` on rows saved before v0.35 (additive migration, alongside `unowned`/`pendingNationOps`/`markers`/`wars`) — legacy games are never wiped and never gain phantom trades/embargoes.
+  - **Game creation (`server/index.ts`, `shared/scenario.ts`).** Fresh games (preset and dynamic) are created with `trades: []` and `embargoes: []`.
+
 ## v0.34.0 — 2026-10-15 16:35
 - **#57: Espionage & Hybrid War — a non-kinetic operations spectrum with a deterministic per-type effect and an exposure backfire.** Every prior turn lever was kinetic (conquest, state-change, region-change, wars, takeovers) or a player-confirmed proposal (nation ops). This version adds `TurnResult.hybrid = { ops: HybridOp[] }` (required, default `{ ops: [] }`) so the model can run **covert, non-kinetic** operations: spies, sabotage, assassination attempts, cyberattacks, economic pressure, disinformation, and proxy support. Unlike territory these **never move borders** — they dip a target's stats or sour a relation. The engine is **fully deterministic (no hidden randomness)**: the LLM declares an intended `outcome` (`success` by default, or `exposed`); a successful op applies its small per-type effect, an `exposed` op **backfires** (no effect, the actor's relation with the target sours one step toward hostile, and an auto `diplomatic`/`failure` event is emitted).
   - **Protocol (`shared/protocol.ts`).** New `HybridOpType` (the seven types) + `HYBRID_OP_TYPES` const, and the `HybridOp` interface (`{ type; from; target; detail?; outcome? }`). `from` is the acting nation (id or unique name — resolved at apply time); `target` is **either** a nation (id/name) **or** a region key (hits that region's sole owner). `TurnResult.hybrid = { ops: HybridOp[] }` is required, placed between `wars` and `markers`.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "history",
-  "version": "0.34.0",
+  "version": "0.35.0",
   "private": true,
   "type": "module",
   "description": "AI-driven alternate-history simulator — the LLM is the world engine (Pax Historia style).",

server/db.test.ts

@@ -33,6 +33,9 @@ function makeState(id: string): GameState {
     },
     // (v0.33.0, #56) no wars.
     wars: [],
+    // (v0.35.0, #58) no active trades or embargoes.
+    trades: [],
+    embargoes: [],
   };
 }
 
@@ -149,6 +152,19 @@ describe('openDb', () => {
     db.close();
   });
 
+  it('(v0.35.0 #58) a legacy row saved before the trades/embargoes fields existed loads with them defaulted to []', () => {
+    const db = openDb(':memory:');
+    const legacy = makeState('legacy');
+    delete (legacy as { trades?: unknown[] }).trades; // a pre-v0.35 save (fields absent)
+    delete (legacy as { embargoes?: unknown[] }).embargoes;
+    db.save(legacy);
+    const loaded = db.load('legacy');
+    expect(loaded).not.toBeNull();
+    expect(loaded!.trades).toEqual([]);
+    expect(loaded!.embargoes).toEqual([]);
+    db.close();
+  });
+
   it('delete removes a game by id and reports absence otherwise', () => {
     const db = openDb(':memory:');
     db.save(makeState('a'));

server/db.ts

@@ -53,6 +53,10 @@ export function openDb(filePath: string): Db {
         // (any pre-v0.33 `war` relation stays a bare/implicit relation — see
         // syncWarRelations, which never force-creates a War entity).
         if (state.wars === undefined) state.wars = [];
+        // (v0.35.0, #58) Same for the trade & embargo economy layer: a
+        // legacy game has no active trades or embargoes.
+        if (state.trades === undefined) state.trades = [];
+        if (state.embargoes === undefined) state.embargoes = [];
         // (v0.28, #46) Rows saved before per-region stats existed are migrated
         // ONCE at load time (and never re-migrated afterwards — the field is
         // then present): each owned region is seeded with a copy of its owner's

server/engine.test.ts

@@ -40,6 +40,7 @@ import {
   runTurn,
   shiftRelationTowardHostile,
   syncWarRelations,
+  validateEconomyOps,
   validateHybridOps,
   validateMarkerOps,
   validateNationOps,
@@ -118,6 +119,9 @@ function baseState(): GameState {
     regionStats: seedRegionStats(nations),
     // (v0.33.0, #56) no wars on a fresh state.
     wars: [],
+    // (v0.35.0, #58) no active trades or embargoes on a fresh state.
+    trades: [],
+    embargoes: [],
   };
 }
 
@@ -555,7 +559,7 @@ describe('validateNationOps (v0.23 #16 P4a)', () => {
       relations: [],
       territoryChanges: [],
       unowned: [],
-      nationOps: [{ kind: 'rename', nationRef: 'France', to: 'French Republic' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] },
+      nationOps: [{ kind: 'rename', nationRef: 'France', to: 'French Republic' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] },
     });
     expect(withOps).not.toBeNull();
     expect(withOps!.nationOps).toEqual([{ kind: 'rename', nationRef: 'France', to: 'French Republic' }]);
@@ -577,7 +581,7 @@ describe('applyTurnResult (nation-op proposals, v0.23 #16 P4a)', () => {
       relations: [],
       territoryChanges: [],
       unowned: [],
-      nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] },
+      nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] },
     });
     expect(next.nations.de.name).toBe('DE'); // still the old name
     expect(next.pendingNationOps).toEqual([{ kind: 'rename', nationRef: 'de', to: 'Reich' }]);
@@ -598,7 +602,7 @@ describe('applyTurnResult (nation-op proposals, v0.23 #16 P4a)', () => {
       relations: [],
       territoryChanges: [],
       unowned: [],
-      nationOps: [{ kind: 'rename', nationRef: 'us', to: 'USA' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] }, // new proposal this turn
+      nationOps: [{ kind: 'rename', nationRef: 'us', to: 'USA' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] }, // new proposal this turn
     });
     expect(next.pendingNationOps).toEqual([
       { kind: 'rename', nationRef: 'de', to: 'Reich' }, // the old one survived
@@ -617,7 +621,7 @@ describe('applyTurnResult (nation-op proposals, v0.23 #16 P4a)', () => {
       relations: [],
       territoryChanges: [],
       unowned: [],
-      nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] },
+      nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] },
     });
     expect(next.pendingNationOps).toEqual([{ kind: 'rename', nationRef: 'de', to: 'Reich' }]);
   });
@@ -1074,7 +1078,7 @@ describe('applyTurnResult', () => {
       relations: [],
       territoryChanges: [],
       unowned: [],
-      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] },
+      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] },
     };
     applyTurnResult(state, result);
     expect(JSON.stringify(state)).toBe(snapshot);
@@ -1091,7 +1095,7 @@ describe('applyTurnResult', () => {
       relations: [],
       territoryChanges: [],
       unowned: [],
-      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] },
+      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] },
     };
     const next = applyTurnResult(state, result);
     expect(next.pending).toEqual([]);
@@ -1114,7 +1118,7 @@ describe('applyTurnResult', () => {
       // is not a real key at all. Both are proposed as a gain by DE.
       territoryChanges: [{ nation: 'de', gain: ['wales-bbbb', 'not-a-region-xyz'], lose: [] }],
       unowned: [],
-      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] },
+      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] },
     };
     const next = applyTurnResult(state, result, new Set(['wales-bbbb']));
     // the valid key was gained (taken from its sole previous owner); the bogus one was ignored
@@ -1140,7 +1144,7 @@ describe('applyTurnResult', () => {
       // released (not in state.unowned), so it does not enter GameState.unowned.
       territoryChanges: [{ nation: 'de', gain: ['POL', 'wales-bbbb'], lose: [] }],
       unowned: [],
-      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] },
+      nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] },
     };
     const next = applyTurnResult(state, result); // no validKeys -> nothing filtered
     expect(next.nations.de.territory).toContain('wales-bbbb');
@@ -1158,7 +1162,7 @@ describe('applyTurnResult (sole-ownership invariants, v0.21 #16 P2)', () => {
     regionChanges: [],
     relations: [],
     unowned: [],
-    nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] },
+    nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] },
   };
 
   it('a double claim (two different gainers, one key) is rejected: the key stays with its original owner', () => {
@@ -1248,7 +1252,7 @@ describe('applyTurnResult (no man\'s land, v0.22 #16 P3)', () => {
     relations: [],
     territoryChanges: [],
     unowned: [],
-    nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] },
+    nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] },
   };
 
   it('a release removes the key from its sole owner and marks it in GameState.unowned', () => {
@@ -1363,7 +1367,7 @@ describe('applyTurnResult (no man\'s land, v0.22 #16 P3)', () => {
 
   it('a lone release is meaningful (it survives the retry/nudge path)', () => {
     expect(
-      isMeaningful({ date: 'x', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [], unowned: ['GBR'], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] } }),
+      isMeaningful({ date: 'x', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [], unowned: ['GBR'], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] } }),
     ).toBe(true);
   });
 
@@ -1670,9 +1674,9 @@ describe('buildSystemPrompt (tool mode, v0.21 #16 P2)', () => {
 
 describe('isMeaningful', () => {
   it('is true with an event, false when everything is empty', () => {
-    expect(isMeaningful({ date: 'x', events: [{ nation: 'uk', type: 'military', title: 't', text: 'b', outcome: 'neutral' }], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] } })).toBe(true);
+    expect(isMeaningful({ date: 'x', events: [{ nation: 'uk', type: 'military', title: 't', text: 'b', outcome: 'neutral' }], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] } })).toBe(true);
-    expect(isMeaningful({ date: 'x', events: [], stateChanges: [{ nation: 'uk', stat: 'military', op: 'set', value: 5 }], regionChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] } })).toBe(true);
+    expect(isMeaningful({ date: 'x', events: [], stateChanges: [{ nation: 'uk', stat: 'military', op: 'set', value: 5 }], regionChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] } })).toBe(true);
-    expect(isMeaningful({ date: 'x', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] } })).toBe(false);
+    expect(isMeaningful({ date: 'x', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [], unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] } })).toBe(false);
   });
 
   it('(v0.23 #16 P4a) a turn that only proposes a nation-op is meaningful (it survives the retry/nudge path)', () => {
@@ -1685,7 +1689,7 @@ describe('isMeaningful', () => {
         relations: [],
         territoryChanges: [],
         unowned: [],
-        nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] },
+        nationOps: [{ kind: 'rename', nationRef: 'de', to: 'Reich' }], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] },
       }),
     ).toBe(true);
   });
@@ -1704,6 +1708,7 @@ describe('isMeaningful', () => {
         takeovers: [],
         wars: { declare: [], end: [] },
         hybrid: { ops: [] },
+        economy: { trade: [], embargo: [] },
         markers: { add: [{ type: 'city', name: 'Lyon', regionKey: 'rhone-rhne' }], remove: [] },
       }),
     ).toBe(true);
@@ -1723,6 +1728,7 @@ describe('isMeaningful', () => {
         takeovers: [{ nationRef: 'de', newRegimeName: 'The Reich' }],
         wars: { declare: [], end: [] },
         hybrid: { ops: [] },
+        economy: { trade: [], embargo: [] },
         markers: { add: [], remove: [] },
       }),
     ).toBe(true);
@@ -1744,6 +1750,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
       takeovers: [{ nationRef: 'de', newRegimeName: 'The Reich' }],
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: { add: [], remove: [] },
     };
     const next = applyTurnResult(state, result);
@@ -1775,6 +1782,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
       takeovers: [{ nationRef: 'uk', newRegimeName: 'The Commonwealth' }],
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: { add: [], remove: [] },
     };
     const next = applyTurnResult(state, result);
@@ -1797,6 +1805,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
       takeovers: [{ nationRef: 'nonexistent', newRegimeName: 'New Name' }],
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: { add: [], remove: [] },
     };
     const next = applyTurnResult(state, result);
@@ -1822,6 +1831,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
       takeovers: [{ nationRef: 'UK', newRegimeName: 'The Empire' }],
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: { add: [], remove: [] },
     };
     const next = applyTurnResult(state, result);
@@ -1846,6 +1856,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
       takeovers: [{ nationRef: 'de', newRegimeName: '   ' }],
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: { add: [], remove: [] },
     });
     expect(validated!.takeovers).toEqual([]);
@@ -1870,6 +1881,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
       ],
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: { add: [], remove: [] },
     };
     const next = applyTurnResult(state, result);
@@ -1892,6 +1904,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
       takeovers: [{ nationRef: 'de', newRegimeName: 'The Reich' }],
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: { add: [], remove: [] },
     };
     const next = applyTurnResult(state, result);
@@ -1912,6 +1925,7 @@ describe('takeovers (regime change, v0.32.0 #54)', () => {
       takeovers: [{ nationRef: 'De', newRegimeName: 'The Reich' }], // 'De' → resolves to 'de' by name
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: { add: [], remove: [] },
     };
     const next = applyTurnResult(state, result);
@@ -1944,6 +1958,7 @@ describe('markers (point placement, v0.27 #44)', () => {
       takeovers: [],
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: { add: [mk('city', 'Strasbourg', 'moselle-rygy')], remove: [] },
     };
     const next = applyTurnResult(state, result, undefined, centroidOf);
@@ -1968,13 +1983,13 @@ describe('markers (point placement, v0.27 #44)', () => {
     const add = [mk('city', 'Strasbourg', 'moselle-rygy')];
     const first = applyTurnResult(state, {
       date: '1939-09-03', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [],
-      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add, remove: [] },
+      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add, remove: [] },
     }, undefined, centroidOf);
     expect(first.markers).toHaveLength(1);
     // a second turn proposes the exact same marker again
     const second = applyTurnResult(first, {
       date: '1939-09-05', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [],
-      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add, remove: [] },
+      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add, remove: [] },
     }, undefined, centroidOf);
     expect(second.markers).toHaveLength(1);
     expect(second.markers[0].id).toBe(first.markers[0].id); // stable id, no second copy
@@ -1999,6 +2014,7 @@ describe('markers (point placement, v0.27 #44)', () => {
       takeovers: [],
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: {
         add: [
           { type: 'city', name: 'Good', regionKey: 'moselle-rygy' }, // valid + centroid → kept
@@ -2044,6 +2060,7 @@ describe('markers (point placement, v0.27 #44)', () => {
       takeovers: [],
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: {
         add: [
           { type: 'city', name: 'NewA', regionKey: 'new-a' },
@@ -2069,7 +2086,7 @@ describe('markers (point placement, v0.27 #44)', () => {
     ];
     const next = applyTurnResult(state, {
       date: '1939-09-03', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [],
-      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [idA, 'zzzz-not-there'] },
+      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [idA, 'zzzz-not-there'] },
     }, undefined, centroidOf);
     expect(next.markers).toHaveLength(1);
     expect(next.markers[0].id).toBe(idB); // only A removed; the bogus id was a no-op
@@ -2085,14 +2102,14 @@ describe('markers (point placement, v0.27 #44)', () => {
     // 1) uk releases the region → the marker becomes ownerless
     const released = applyTurnResult(state, {
       date: '1939-09-03', events: [], stateChanges: [], regionChanges: [], relations: [], territoryChanges: [],
-      unowned: ['moselle-rygy'], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] },
+      unowned: ['moselle-rygy'], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] },
     }, undefined, centroidOf);
     expect(released.markers[0].ownerNationId).toBeNull();
     // 2) de re-claims the region → the marker's owner follows to de
     const reclaimed = applyTurnResult(released, {
       date: '1939-09-05', events: [], stateChanges: [], regionChanges: [], relations: [],
       territoryChanges: [{ nation: 'de', gain: ['moselle-rygy'], lose: [] }],
-      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, markers: { add: [], remove: [] },
+      unowned: [], nationOps: [], takeovers: [], wars: { declare: [], end: [] }, hybrid: { ops: [] }, economy: { trade: [], embargo: [] }, markers: { add: [], remove: [] },
     }, undefined, centroidOf);
     expect(reclaimed.markers[0].ownerNationId).toBe('de');
   });
@@ -2160,6 +2177,7 @@ describe('markers (point placement, v0.27 #44)', () => {
       nationOps: [],
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: { add: [{ type: 'city', name: 'Strasbourg', regionKey: 'moselle-rygy' }], remove: [] },
     });
     const { state } = await runTurn({
@@ -2230,6 +2248,9 @@ function mkTurnState(
     markers: [],
     regionStats,
     wars: [],
+    // (v0.35.0, #58) no active trades or embargoes on a fresh state.
+    trades: [],
+    embargoes: [],
   };
 }
 
@@ -2246,6 +2267,7 @@ function mkTurnResult(partial: Partial<TurnResult>): TurnResult {
     takeovers: partial.takeovers ?? [],
     wars: partial.wars ?? { declare: [], end: [] },
     hybrid: partial.hybrid ?? { ops: [] },
+    economy: partial.economy ?? { trade: [], embargo: [] },
     markers: partial.markers ?? { add: [], remove: [] },
   };
 }
@@ -2969,6 +2991,7 @@ describe('validateTakeovers (v0.32.0 #54)', () => {
       takeovers: [{ nationRef: 'de', newRegimeName: 'The Reich' }, { nationRef: 'bad', newRegimeName: '' }],
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: { add: [], remove: [] },
     });
     expect(withTakeovers).not.toBeNull();
@@ -3355,6 +3378,7 @@ describe('isMeaningful — wars (v0.33.0 #56)', () => {
         takeovers: [],
         wars: { declare: [{ sides: ['a', 'b'] }], end: [] },
         hybrid: { ops: [] },
+        economy: { trade: [], embargo: [] },
         markers: { add: [], remove: [] },
       }),
     ).toBe(true);
@@ -3374,6 +3398,7 @@ describe('isMeaningful — wars (v0.33.0 #56)', () => {
         takeovers: [],
         wars: { declare: [], end: [{ id: 'w1', outcome: 'armistice' }] },
         hybrid: { ops: [] },
+        economy: { trade: [], embargo: [] },
         markers: { add: [], remove: [] },
       }),
     ).toBe(true);
@@ -3393,6 +3418,7 @@ describe('isMeaningful — wars (v0.33.0 #56)', () => {
         takeovers: [],
         wars: { declare: [], end: [] },
         hybrid: { ops: [] },
+        economy: { trade: [], embargo: [] },
         markers: { add: [], remove: [] },
       }),
     ).toBe(false);
@@ -3839,3 +3865,268 @@ describe('stub — hybrid (v0.34.0 #57)', () => {
     expect(result.hybrid).toEqual({ ops: [] });
   });
 });
+
+// ============================================================================
+// Economy — trade & embargo (v0.35.0, #58)
+//
+// The bilateral trade + embargo layer: `GameState.trades` (symmetric pairs,
+// stored sorted) and `GameState.embargoes` (ordered from → target). A turn's
+// `economy` ops declare/lift them (refs resolved at apply time); EVERY
+// committed turn the full active lists apply their deterministic per-turn
+// effect (trade: both parties' economy up; embargo: the target's economy
+// down), clamped and mirrored to `regionStats`, and any trade/embargo whose
+// two nations are on opposite sides of an active war is auto-suspended.
+// ============================================================================
+
+describe('validateEconomyOps (v0.35.0 #58)', () => {
+  it('non-object input yields empty trade/embargo', () => {
+    expect(validateEconomyOps(undefined)).toEqual({ trade: [], embargo: [] });
+    expect(validateEconomyOps(null)).toEqual({ trade: [], embargo: [] });
+    expect(validateEconomyOps('x')).toEqual({ trade: [], embargo: [] });
+    expect(validateEconomyOps([])).toEqual({ trade: [], embargo: [] });
+  });
+
+  it('keeps well-formed ops (trimmed refs, lift normalized) and drops malformed ones', () => {
+    const out = validateEconomyOps({
+      trade: [{ a: ' uk ', b: 'de' }, { a: 'us', b: 'de', lift: true }, 'junk', null, { a: 'us' }],
+      embargo: [{ from: 'uk', target: 'de', lift: true }, { from: 'uk', target: 'de' }, { from: 'uk' }],
+    });
+    expect(out.trade).toEqual([{ a: 'uk', b: 'de' }, { a: 'us', b: 'de', lift: true }]);
+    expect(out.embargo).toEqual([{ from: 'uk', target: 'de', lift: true }, { from: 'uk', target: 'de' }]);
+  });
+});
+
+describe('validateTurnResult — economy (v0.35.0 #58)', () => {
+  it('a bare (economy-less) input gets economy defaulted to { trade: [], embargo: [] }', () => {
+    const out = validateTurnResult({ date: '1939-09-03', events: [], stateChanges: [] });
+    expect(out).not.toBeNull();
+    expect(out!.economy).toEqual({ trade: [], embargo: [] });
+  });
+
+  it('a well-formed economy payload is kept', () => {
+    const out = validateTurnResult({
+      date: '1939-09-03',
+      events: [],
+      stateChanges: [],
+      economy: { trade: [{ a: 'a', b: 'b' }], embargo: [{ from: 'a', target: 'b', lift: true }] },
+    });
+    expect(out).not.toBeNull();
+    expect(out!.economy).toEqual({
+      trade: [{ a: 'a', b: 'b' }],
+      embargo: [{ from: 'a', target: 'b', lift: true }],
+    });
+  });
+});
+
+describe('applyTurnResult — economy (v0.35.0 #58)', () => {
+  it('a declared trade: both parties gain +1 economy (stats + regionStats mirror), and the agreement persists', () => {
+    const state = mkTurnState(
+      { a: mkNation('a', NS(50, 60, 50, 50), ['ra1']), b: mkNation('b', NS(50, 70, 50, 50), ['rb1']) },
+      { ra1: RS(50, 60, 50, 50), rb1: RS(50, 70, 50, 50) },
+    );
+    const next = applyTurnResult(state, mkTurnResult({ economy: { trade: [{ a: 'a', b: 'b' }], embargo: [] } }));
+    expect(next.trades).toEqual([{ a: 'a', b: 'b' }]);
+    expect(next.nations.a.stats.economy).toBe(61);
+    expect(next.nations.b.stats.economy).toBe(71);
+    expect(next.regionStats.ra1.economy).toBe(61);
+    expect(next.regionStats.rb1.economy).toBe(71);
+  });
+
+  it('the per-turn effect applies to the FULL active lists every turn (a later empty turn re-applies it)', () => {
+    let state = mkTurnState(
+      { a: mkNation('a', NS(50, 60, 50, 50), ['ra1']), b: mkNation('b', NS(50, 70, 50, 50), ['rb1']) },
+      { ra1: RS(50, 60, 50, 50), rb1: RS(50, 70, 50, 50) },
+    );
+    state = applyTurnResult(state, mkTurnResult({ economy: { trade: [{ a: 'a', b: 'b' }], embargo: [] } }));
+    expect(state.nations.a.stats.economy).toBe(61);
+    expect(state.nations.b.stats.economy).toBe(71);
+    // the next (empty) turn: the still-active trade applies its effect again
+    state = applyTurnResult(state, mkTurnResult({}));
+    expect(state.trades).toEqual([{ a: 'a', b: 'b' }]);
+    expect(state.nations.a.stats.economy).toBe(62);
+    expect(state.nations.b.stats.economy).toBe(72);
+    expect(state.regionStats.ra1.economy).toBe(62);
+    expect(state.regionStats.rb1.economy).toBe(72);
+  });
+
+  it('an embargo lowers only the target economy; the imposer is untouched', () => {
+    const state = mkTurnState(
+      { a: mkNation('a', NS(50, 60, 50, 50), ['ra1']), b: mkNation('b', NS(50, 70, 50, 50), ['rb1']) },
+      { ra1: RS(50, 60, 50, 50), rb1: RS(50, 70, 50, 50) },
+    );
+    const next = applyTurnResult(state, mkTurnResult({ economy: { trade: [], embargo: [{ from: 'a', target: 'b' }] } }));
+    expect(next.embargoes).toEqual([{ from: 'a', target: 'b' }]);
+    expect(next.nations.a.stats.economy).toBe(60); // imposer unchanged
+    expect(next.nations.b.stats.economy).toBe(69); // the target dips 1
+    expect(next.regionStats.ra1.economy).toBe(60);
+    expect(next.regionStats.rb1.economy).toBe(69);
+  });
+
+  it('declares are idempotent: a trade is one symmetric (sorted) agreement; embargoes keep both ordered directions (a duplicate is dropped)', () => {
+    const state = mkTurnState(
+      { a: mkNation('a', NS(50, 50, 50, 50), ['ra1']), b: mkNation('b', NS(50, 50, 50, 50), ['rb1']) },
+      { ra1: RS(50, 50, 50, 50), rb1: RS(50, 50, 50, 50) },
+    );
+    const next = applyTurnResult(state, mkTurnResult({
+      economy: {
+        trade: [{ a: 'b', b: 'a' }, { a: 'a', b: 'b' }], // the same pair, both orders → one agreement
+        embargo: [{ from: 'a', target: 'b' }, { from: 'b', target: 'a' }, { from: 'a', target: 'b' }], // both directions kept, the duplicate dropped
+      },
+    }));
+    expect(next.trades).toEqual([{ a: 'a', b: 'b' }]);
+    expect(next.embargoes).toEqual([{ from: 'a', target: 'b' }, { from: 'b', target: 'a' }]);
+    // the net delta is +1 (trade) - 1 (the embargo pointing at each) = 0 for both
+    expect(next.nations.a.stats.economy).toBe(50);
+    expect(next.nations.b.stats.economy).toBe(50);
+  });
+
+  it('lift: true ends a trade (the effect stops) and lifts an embargo; lifting an absent one is a no-op', () => {
+    let state = mkTurnState(
+      { a: mkNation('a', NS(50, 60, 50, 50), ['ra1']), b: mkNation('b', NS(50, 70, 50, 50), ['rb1']) },
+      { ra1: RS(50, 60, 50, 50), rb1: RS(50, 70, 50, 50) },
+    );
+    state = applyTurnResult(state, mkTurnResult({ economy: { trade: [{ a: 'a', b: 'b' }], embargo: [{ from: 'a', target: 'b' }] } }));
+    // trade +1 for both; the embargo hits b only → a 61, b 70
+    expect(state.nations.a.stats.economy).toBe(61);
+    expect(state.nations.b.stats.economy).toBe(70);
+    // lift both on the next turn (the trade lift is name/ref-insensitive: b→a resolves to the same sorted pair)
+    state = applyTurnResult(state, mkTurnResult({ economy: { trade: [{ a: 'b', b: 'a', lift: true }], embargo: [{ from: 'a', target: 'b', lift: true }] } }));
+    expect(state.trades).toEqual([]);
+    expect(state.embargoes).toEqual([]);
+    expect(state.nations.a.stats.economy).toBe(61); // no further change
+    expect(state.nations.b.stats.economy).toBe(70);
+    // lifting again (absent) is a no-op
+    state = applyTurnResult(state, mkTurnResult({ economy: { trade: [{ a: 'a', b: 'b', lift: true }], embargo: [{ from: 'a', target: 'b', lift: true }] } }));
+    expect(state.trades).toEqual([]);
+    expect(state.embargoes).toEqual([]);
+  });
+
+  it('name refs resolve (id first, then unique case-insensitive name); the pair is stored sorted by id', () => {
+    const state = mkTurnState(
+      { a: { ...mkNation('a', NS(50, 60, 50, 50), ['ra1']), name: 'Alpha' }, b: mkNation('b', NS(50, 70, 50, 50), ['rb1']) },
+      { ra1: RS(50, 60, 50, 50), rb1: RS(50, 70, 50, 50) },
+    );
+    const next = applyTurnResult(state, mkTurnResult({ economy: { trade: [{ a: 'alpha', b: 'B' }], embargo: [] } }));
+    expect(next.trades).toEqual([{ a: 'a', b: 'b' }]);
+  });
+
+  it('unknown, ambiguous, and self-pairing refs are dropped (never throws)', () => {
+    const dupA: Nation = { ...mkNation('a1', NS(50, 50, 50, 50), ['ra1']), name: 'DUP' };
+    const dupB: Nation = { ...mkNation('a2', NS(50, 50, 50, 50), ['rb1']), name: 'DUP' };
+    const c = mkNation('c', NS(50, 50, 50, 50), ['rc1']);
+    const state = mkTurnState(
+      { a1: dupA, a2: dupB, c },
+      { ra1: RS(50, 50, 50, 50), rb1: RS(50, 50, 50, 50), rc1: RS(50, 50, 50, 50) },
+    );
+    const next = applyTurnResult(state, mkTurnResult({
+      economy: {
+        trade: [
+          { a: 'zzz', b: 'c' }, // unknown
+          { a: 'c', b: 'c' }, // self
+          { a: 'DUP', b: 'c' }, // ambiguous name
+        ],
+        embargo: [{ from: 'zzz', target: 'c' }, { from: 'c', target: 'c' }, { from: 'DUP', target: 'c' }],
+      },
+    }));
+    expect(next.trades).toEqual([]);
+    expect(next.embargoes).toEqual([]);
+  });
+
+  it('auto-suspension: an existing trade is removed when its two nations go to war this turn', () => {
+    const state = warState({ a: warN('a'), b: warN('b') }, []);
+    state.trades = [{ a: 'a', b: 'b' }];
+    const next = applyTurnResult(state, mkTurnResult({ wars: { declare: [{ sides: ['a', 'b'] }], end: [] } }));
+    expect(next.wars).toHaveLength(1);
+    expect(next.wars[0].status).toBe('active');
+    expect(next.trades).toEqual([]); // the war severs the economic link
+  });
+
+  it('a trade declared this turn between two nations that also go to war this turn is dropped', () => {
+    const state = warState({ a: warN('a'), b: warN('b') }, []);
+    const next = applyTurnResult(state, mkTurnResult({
+      wars: { declare: [{ sides: ['a', 'b'] }], end: [] },
+      economy: { trade: [{ a: 'a', b: 'b' }], embargo: [] },
+    }));
+    expect(next.wars).toHaveLength(1);
+    expect(next.trades).toEqual([]);
+  });
+
+  it('a trade/embargo between a belligerent and a non-belligerent survives the war declaration', () => {
+    const state = warState({ a: warN('a'), b: warN('b'), c: warN('c') }, []);
+    state.trades = [{ a: 'a', b: 'c' }];
+    state.embargoes = [{ from: 'a', target: 'c' }];
+    const next = applyTurnResult(state, mkTurnResult({ wars: { declare: [{ sides: ['a', 'b'] }], end: [] } }));
+    expect(next.trades).toEqual([{ a: 'a', b: 'c' }]);
+    expect(next.embargoes).toEqual([{ from: 'a', target: 'c' }]);
+  });
+
+  it('an ended (armistice) war does not suspend a trade', () => {
+    const state = warState(
+      { a: warN('a'), b: warN('b') },
+      [{ id: 'w1', sides: ['a', 'b'], declaredTurn: 1, status: 'armistice' }],
+    );
+    state.trades = [{ a: 'a', b: 'b' }];
+    const next = applyTurnResult(state, mkTurnResult({}));
+    expect(next.trades).toEqual([{ a: 'a', b: 'b' }]);
+  });
+});
+
+describe('isMeaningful — economy (v0.35.0 #58)', () => {
+  it('a trade-only or embargo-only turn is meaningful; an empty economy is not', () => {
+    expect(isMeaningful(mkTurnResult({ economy: { trade: [{ a: 'a', b: 'b' }], embargo: [] } }))).toBe(true);
+    expect(isMeaningful(mkTurnResult({ economy: { trade: [], embargo: [{ from: 'a', target: 'b' }] } }))).toBe(true);
+    expect(isMeaningful(mkTurnResult({}))).toBe(false);
+  });
+});
+
+describe('buildSystemPrompt — economy contract (v0.35.0 #58)', () => {
+  it('documents the economy field and its constraints in both modes', () => {
+    for (const withTools of [false, true]) {
+      const p = buildSystemPrompt(preset, withTools);
+      expect(p).toContain('"economy": {"trade":');
+      expect(p).toContain('Economy ("economy") is the trade & embargo layer');
+      expect(p).toContain('at most 1-2 operations per turn');
+      expect(p).toContain('suspended automatically by the engine');
+    }
+  });
+});
+
+describe('buildUserPrompt — economy (v0.35.0 #58)', () => {
+  const state = mkTurnState(
+    { a: mkNation('a', NS(50, 50, 50, 50), ['ra1']), b: mkNation('b', NS(50, 50, 50, 50), ['rb1']) },
+    { ra1: RS(50, 50, 50, 50), rb1: RS(50, 50, 50, 50) },
+  );
+
+  it('carries the active trades and embargoes when provided', () => {
+    const out = JSON.parse(
+      buildUserPrompt(state, [], undefined, undefined, [], [], undefined, undefined, [{ a: 'a', b: 'b' }], [{ from: 'a', target: 'b' }]),
+    );
+    expect(out.trades).toEqual([{ a: 'a', b: 'b' }]);
+    expect(out.embargoes).toEqual([{ from: 'a', target: 'b' }]);
+  });
+
+  it('omits the trades/embargoes fields entirely when undefined', () => {
+    const out = JSON.parse(buildUserPrompt(state, [], undefined, undefined, [], [], undefined, undefined));
+    expect(out).not.toHaveProperty('trades');
+    expect(out).not.toHaveProperty('embargoes');
+  });
+});
+
+describe('stub — economy (v0.35.0 #58)', () => {
+  it('the deterministic stub returns empty economy ops (it never declares a trade or an embargo)', () => {
+    const payload = {
+      state: {
+        turn: 1,
+        date: '1939-09-01',
+        playerNationId: 'uk',
+        nations: {
+          uk: { stats: { military: 50, economy: 50, stability: 50, population: 50 }, territory: ['a'] },
+          de: { stats: { military: 60, economy: 60, stability: 60, population: 60 }, territory: ['b'] },
+        },
+      },
+      pending: [{ kind: 'action' as const, text: 'test' }],
+    };
+    const result = deterministicTurn(payload);
+    expect(result.economy).toEqual({ trade: [], embargo: [] });
+  });
+});

server/engine.ts

@@ -4,6 +4,7 @@
 // and (4) builds the advisor brainstorm prompt. The network call itself lives in
 // llm.ts (injectable) and is invoked by runTurn.
 import type {
+  Embargo,
   EventOutcome,
   EventType,
   GameState,
@@ -15,6 +16,7 @@ import type {
   RegionStats,
   RoundItem,
   StatKey,
+  TradeAgreement,
   War,
 } from '../shared/types';
 import { EVENT_TYPES, RELATION_STATUSES } from '../shared/types';
@@ -31,6 +33,9 @@ import {
   markerId,
   MAX_MARKERS,
   nationForPrompt,
+  type EconomyEmbargoOp,
+  type EconomyOps,
+  type EconomyTradeOp,
   type HybridOp,
   type HybridOpType,
   type MarkerInfo,
@@ -163,7 +168,9 @@ export function playerFrontier(
  * (v0.21, #16 P2): the model may only move regions across a shared border, and
  * may verify borders with the tool before answering. The contract also
  * documents the `nationOps` proposal queue (v0.23, #16 P4a) — rename plus the
- * split/merge shapes applied on player confirm (v0.24, #16 P4b).
+ * split/merge shapes applied on player confirm (v0.24, #16 P4b), and the
+ * trade & embargo economy layer (v0.35.0, #58): bilateral trades and
+ * unilateral embargoes, each ended with a `lift: true` op.
  */
 export function buildSystemPrompt(preset: Preset, withNeighboursTool = false): string {
   const rules = preset.simulationRules
@@ -216,6 +223,7 @@ export function buildSystemPrompt(preset: Preset, withNeighboursTool = false): s
     '  "takeovers": [{"nationRef":"<nation id or name>","newRegimeName":"<name of the new regime>"}],',
     '  "wars": {"declare":[{"sides":["<nationId>","<nationId>"],"aims":["<short aim>"]}],"end":[{"id":"<war id>","outcome":"<armistice|capitulation>","terms":"<short terms>"}]},',
     '  "hybrid": {"ops":[{"type":"<spy|sabotage|assassinate|cyber|economic|information|proxy>","from":"<nation id or name>","target":"<nation id or name, or region key>","detail":"<short detail>","outcome":"<success|exposed>"}]},',
+    '  "economy": {"trade":[{"a":"<nationId>","b":"<nationId>","lift":<true|false>}],"embargo":[{"from":"<nationId>","target":"<nationId>","lift":<true|false>}]},',
     '  "markers": {"add":[{"type":"<city|factory|army|port|capital|fleet|rocket|gathering>","name":"<short name>","regionKey":"<region key>"}],"remove":["<marker id>"]}',
     '}',
     '',
@@ -236,6 +244,7 @@ export function buildSystemPrompt(preset: Preset, withNeighboursTool = false): s
     '- Takeover (automatic, NOT player-confirmed): add {"takeovers":[{"nationRef":"<nation id or name>","newRegimeName":"<name of the new regime>"}]} when a low-stability nation (e.g. stability < 30) hosting a "gathering" marker is overthrown in a coup or revolution. This renames the nation to the new regime (e.g. "France" → "Vichy Regime"). Also emit a narrative "event" (political or social, outcome "success") and a stability/economy shock via "stateChanges". A takeover is an automatic in-world regime change — use "nationOps" rename only for a diplomatic/political name change that the player must confirm.',
     '- Wars ("wars") are named conflicts, each with a stable id. To DECLARE one, add {"declare":[{"sides":["<id>","<id>"],"aims":[...]}]} with at least 2 distinct belligerents: while it is active the engine AUTOMATICALLY sets both directions of every warring pair\'s relation to "war" and drags in the mutual-defense allies of each belligerent, so do NOT also emit a "war" relation for those pairs (you can never "make peace" between them without ending the war). To END an active war, add {"end":[{"id":"<war id from the user message\'s "wars" field>","outcome":"<armistice|capitulation>"}]} — only active wars can be ended, and when one ends its belligerent pairs fall back to "hostile". Propose at most 1-2 declarations per turn and narrate each declaration and each ending in "events".',
     '- Covert / hybrid ops ("hybrid.ops") are non-kinetic operations — spies, sabotage, assassination attempts, cyberattacks, economic pressure, disinformation, and proxy support. Unlike territory they NEVER move borders: a successful op applies a small, deterministic effect (a small dip in the target\'s economy / stability / military for sabotage / assassinate / cyber / economic, or a relation nudge toward hostile for information / proxy), while an "exposed" op backfires (no effect, and the actor\'s relation with the target sours by one step toward hostile). "target" may be a nation id / name or a region key (a region key hits that region\'s sole owner). Keep each detail short, propose at most a few per turn, and narrate each op in "events".',
+    '- Economy ("economy") is the trade & embargo layer: a bilateral trade (trade: {"a":"..","b":".."}) gives BOTH parties a small, deterministic economy gain every turn, while a unilateral embargo (embargo: {"from":"..","target":".."}) lowers only the TARGET\'s economy every turn. Omit "lift" to declare / impose, and set "lift":true to end or lift an existing one (the user message\'s "trades"/"embargoes" fields list what is currently active). Propose at most 1-2 operations per turn and narrate each one in "events". Trades and embargoes between nations at war are suspended automatically by the engine.',
     '- Prefer 1-4 events per turn; keep each text 1-3 sentences.',
     '- Keep your internal reasoning brief (a few sentences) and go straight to the JSON result; do not over-deliberate or re-derive facts already present in the state.',
     '- Keep every stat value between 0 and 100.',
@@ -253,6 +262,9 @@ export function buildSystemPrompt(preset: Preset, withNeighboursTool = false): s
  * other consumer) can read the exact items. The framing instruction tells the
  * model to simulate the combined consequences of the whole batch (or to let the
  * world advance on its own when the batch is empty) and return one TurnResult.
+ * (v0.35.0, #58) It also carries the currently active `trades` / `embargoes`
+ * (omitted entirely when undefined, like the other optional fields) so the
+ * model can reference them — and `lift` them — in `TurnResult.economy`.
  */
 export function buildUserPrompt(
   state: GameState,
@@ -295,6 +307,20 @@ export function buildUserPrompt(
    * Omitted entirely when undefined.
    */
   relations?: Record<string, RelationStatus>,
+  /**
+   * (v0.35.0, #58) The currently active bilateral trade agreements (each a
+   * pair of nation ids). Emitted verbatim (even when empty) so the model
+   * knows which trades exist and can end one with `economy.trade` +
+   * `lift: true`. Omitted entirely when undefined.
+   */
+  trades?: TradeAgreement[],
+  /**
+   * (v0.35.0, #58) The currently active unilateral embargoes (each an
+   * `from` → `target` pair of nation ids). Emitted verbatim (even when
+   * empty) so the model knows which embargoes are in force and can lift one
+   * with `economy.embargo` + `lift: true`. Omitted entirely when undefined.
+   */
+  embargoes?: Embargo[],
 ): string {
   const player = state.nations[state.playerNationId];
   const playerName = player?.name ?? state.playerNationId;
@@ -409,6 +435,8 @@ export function buildUserPrompt(
   if (markers !== undefined) payload.markers = markers;
   if (wars !== undefined) payload.wars = wars;
   if (relations !== undefined) payload.relations = relations;
+  if (trades !== undefined) payload.trades = trades;
+  if (embargoes !== undefined) payload.embargoes = embargoes;
   return JSON.stringify(payload, null, 2);
 }
 
@@ -549,6 +577,7 @@ export function validateTurnResult(
     takeovers: [],
     wars: { declare: [], end: [] },
     hybrid: { ops: [] },
+    economy: { trade: [], embargo: [] },
     markers: { add: [], remove: [] },
   };
 
@@ -653,6 +682,12 @@ export function validateTurnResult(
   // exposed backfire.
   result.hybrid = { ops: validateHybridOps(o.hybrid) };
 
+  // (v0.35.0, #58) Trade & embargo ops: a no-`lift` op declares / imposes,
+  // `lift: true` ends / lifts. Refs stay raw here and are resolved at apply
+  // time against the real state (like wars / hybrid ops); unknown /
+  // ambiguous / self-pairing ops are dropped there, never thrown.
+  result.economy = validateEconomyOps(o.economy);
+
   // (v0.27, #44) Map-marker ops: new placements (validated here) and
   // removals by stable id. Applied by applyTurnResult after the territory
   // moves (a new marker's owner is the region's post-turn owner).
@@ -881,6 +916,52 @@ function validateHybridOpsList(raw: unknown[]): HybridOp[] {
   return out;
 }
 
+/**
+ * (v0.35.0, #58) Validate the raw `economy` object of a turn into a safe
+ * {@link EconomyOps}. Defensive like the rest of the parser — never throws.
+ * `trade`: each op needs non-empty `a` and `b` refs (a nation's id or unique
+ * name, capped at 200 chars) and a boolean `lift` (default false = declare);
+ * ops with a missing ref are dropped — ref resolution and the
+ * a≠b / from≠target checks happen at apply time against the real state
+ * (like wars / hybrid ops, whose raw refs are kept here). `embargo`: each op
+ * needs non-empty `from` and `target` refs and a boolean `lift` (default
+ * false = impose). A missing / malformed top-level object yields
+ * `{ trade: [], embargo: [] }`.
+ */
+export function validateEconomyOps(raw: unknown): EconomyOps {
+  const out: EconomyOps = { trade: [], embargo: [] };
+  if (!raw || typeof raw !== 'object' || Array.isArray(raw)) return out;
+  const o = raw as Record<string, unknown>;
+
+  if (Array.isArray(o.trade)) {
+    for (const e of o.trade) {
+      if (!e || typeof e !== 'object') continue;
+      const t = e as Record<string, unknown>;
+      const a = str(t.a, 200);
+      const b = str(t.b, 200);
+      if (!a || !b) continue;
+      const op: EconomyTradeOp = { a, b };
+      if (t.lift === true) op.lift = true;
+      out.trade.push(op);
+    }
+  }
+
+  if (Array.isArray(o.embargo)) {
+    for (const e of o.embargo) {
+      if (!e || typeof e !== 'object') continue;
+      const t = e as Record<string, unknown>;
+      const from = str(t.from, 200);
+      const target = str(t.target, 200);
+      if (!from || !target) continue;
+      const op: EconomyEmbargoOp = { from, target };
+      if (t.lift === true) op.lift = true;
+      out.embargo.push(op);
+    }
+  }
+
+  return out;
+}
+
 /**
  * (v0.33.0, #56) The UNORDERED pairs of belligerents of a set of ACTIVE
  * wars: a war with sides [a, b, c] contributes the pairs {a,b}, {a,c},
@@ -1165,6 +1246,128 @@ function applyHybridOp(
   else if (op.type === 'proxy') shiftRelationTowardHostile(next, from, target.nation.id, 'rival');
 }
 
+// --- Economy ops: trade + embargo (v0.35.0, #58) ------------------------------
+
+/**
+ * (v0.35.0, #58) The per-turn economic effect of the economy layer, applied
+ * EVERY committed turn (not just to this turn's declares): each active
+ * bilateral trade grants both parties a small, deterministic economy gain;
+ * each active embargo applies a small, deterministic economy dip to the
+ * target only. Clamped to 0–100. The effect lands on `stats.economy` AND on
+ * every region the nation owns (`regionStats`), mirroring the hybrid-op
+ * effect, and each affected nation's derived stats are re-derived afterwards
+ * (the same 0-region / no-entry guards as `applyHybridOp`). No-op when there
+ * are no active trades or embargoes. Never throws.
+ */
+const TRADE_ECONOMY_BONUS = 1;
+const EMBARGO_ECONOMY_PENALTY = 1;
+
+export function applyEconomyEffects(
+  next: GameState,
+  geoOf?: (key: string) => { area: number; population: number } | undefined,
+): void {
+  if (next.trades.length === 0 && next.embargoes.length === 0) return;
+
+  // nation id -> signed economy delta (trades add for both parties, embargoes
+  // subtract for the target; deltas accumulate for nations hit by several).
+  const delta = new Map<string, number>();
+  for (const t of next.trades) {
+    for (const id of [t.a, t.b]) {
+      delta.set(id, (delta.get(id) ?? 0) + TRADE_ECONOMY_BONUS);
+    }
+  }
+  for (const e of next.embargoes) {
+    delta.set(e.target, (delta.get(e.target) ?? 0) - EMBARGO_ECONOMY_PENALTY);
+  }
+
+  const affected = new Set<string>();
+  for (const [id, d] of delta) {
+    const n = next.nations[id];
+    if (!n) continue; // a nation removed this turn (a merge): the delta is dropped
+    const cur = clampStat(n.stats.economy + d);
+    if (cur === n.stats.economy) continue; // no change (already at the clamp)
+    n.stats.economy = cur;
+    for (const key of n.territory) {
+      const rs = next.regionStats[key];
+      if (rs) rs.economy = clampStat(rs.economy + d);
+    }
+    affected.add(id);
+  }
+
+  if (affected.size > 0) {
+    for (const id of affected) {
+      const n = next.nations[id];
+      if (n && n.territory.length > 0 && n.territory.some((k) => next.regionStats[k])) {
+        n.stats = deriveNationStats(n.territory, next.regionStats, geoOf);
+      }
+    }
+  }
+}
+
+/**
+ * (v0.35.0, #58) Apply the turn's economy ops to the active lists on
+ * `next`, RESOLVING the (possibly name-based) refs against the current
+ * state: a no-`lift` trade op declares the bilateral agreement (idempotent —
+ * an already-active pair is not duplicated; the pair is stored sorted, since
+ * a trade is symmetric); `lift: true` ends it (a no-op when absent). A no-
+ * `lift` embargo op imposes the unilateral embargo (idempotent — the ordered
+ * from→target pair is kept as-is); `lift: true` lifts it. An op whose refs
+ * don't resolve to distinct EXISTING nations is dropped (defensive — never
+ * throws). Mutates `next` in place.
+ */
+function applyEconomyOps(next: GameState, ops: EconomyOps): void {
+  const tradeKey = (a: string, b: string): string => (a < b ? `${a}\u0000${b}` : `${b}\u0000${a}`);
+  const embargoKey = (f: string, t: string): string => `${f}\u0000${t}`;
+
+  for (const op of ops.trade) {
+    const a = resolveNationRef(next, op.a);
+    const b = resolveNationRef(next, op.b);
+    if (!a || !b || a === b) continue; // unknown / ambiguous / self: drop
+    const key = tradeKey(a, b);
+    if (op.lift === true) {
+      next.trades = next.trades.filter((t) => tradeKey(t.a, t.b) !== key);
+    } else if (!next.trades.some((t) => tradeKey(t.a, t.b) === key)) {
+      // stored sorted (a < b): a trade is symmetric, so the agreement has a
+      // canonical shape no matter which way the LLM named the pair.
+      next.trades.push(a < b ? { a, b } : { a: b, b: a });
+    }
+  }
+
+  for (const op of ops.embargo) {
+    const from = resolveNationRef(next, op.from);
+    const target = resolveNationRef(next, op.target);
+    if (!from || !target || from === target) continue; // unknown / ambiguous / self: drop
+    const key = embargoKey(from, target);
+    if (op.lift === true) {
+      next.embargoes = next.embargoes.filter((e) => embargoKey(e.from, e.target) !== key);
+    } else if (!next.embargoes.some((e) => embargoKey(e.from, e.target) === key)) {
+      next.embargoes.push({ from, target });
+    }
+  }
+}
+
+/**
+ * (v0.35.0, #58) Auto-suspend the economy layer when war breaks out: any
+ * active trade or embargo whose two nations are on OPPOSITE sides of an
+ * active war (v0.33, #56) is removed — a war severs the economic link, so
+ * the suspended agreement stops producing its per-turn effect from now on.
+ * A trade/embargo between two non-belligerents, or between two nations on
+ * the SAME side, is untouched. Mutates `next` in place; idempotent. Must be
+ * called AFTER the war declare/end ops of the turn (so it sees the final
+ * `next.wars`). Never throws.
+ */
+function suspendEconomyOnWar(next: GameState): void {
+  if (next.trades.length === 0 && next.embargoes.length === 0) return;
+  const warring = activeWarPairs(next.wars);
+  const atWarNow = (x: string, y: string): boolean => {
+    if (x === y) return false;
+    const key = x < y ? `${x}\u0000${y}` : `${y}\u0000${x}`;
+    return warring.has(key);
+  };
+  next.trades = next.trades.filter((t) => !atWarNow(t.a, t.b));
+  next.embargoes = next.embargoes.filter((e) => !atWarNow(e.from, e.target));
+}
+
 /**
  * A turn is "meaningful" if it produced at least an event, a stat change, a
  * no-man's-land release (v0.22 #16 P3: a release is a real world change even
@@ -1190,6 +1393,10 @@ export function isMeaningful(result: TurnResult): boolean {
     // (v0.34.0, #57) a hybrid op (a successful one or an exposed backfire) is
     // a real world change (a stat dip or a soured relation).
     result.hybrid.ops.length > 0 ||
+    // (v0.35.0, #58) a trade declared/ended or an embargo imposed/lifted this
+    // turn is a real world change (the active economy lists moved).
+    result.economy.trade.length > 0 ||
+    result.economy.embargo.length > 0 ||
     // (v0.27, #44) a marker placed or removed this turn is a real world change.
     result.markers.add.length > 0 ||
     result.markers.remove.length > 0
@@ -1546,6 +1753,32 @@ export function applyTurnResult(
     applyHybridOp(next, op, geoOf, validKeys, regionNameOf, actingTurn);
   }
 
+  // --- Trade & embargo economy layer (v0.35.0, #58) ---
+  //
+  // Placed AFTER the wars block (so the auto-suspension sees the FINAL
+  // next.wars, including wars declared this turn) and before markers /
+  // nationOps (which never touch the economy lists). Order:
+  //   (1) APPLY OPS: the turn's declare/lift ops mutate the active
+  //       GameState.trades / GameState.embargoes lists (a declare is
+  //       idempotent; refs resolved against the current state, unknown /
+  //       ambiguous / self-pairing ops dropped).
+  //   (2) WAR AUTO-SUSPENSION: any active trade or embargo whose two
+  //       nations are on opposite sides of an active war is removed —
+  //       a war severs the economic link, so the suspended agreement
+  //       stops producing its per-turn effect from now on (this also
+  //       drops a trade declared this turn between two nations that just
+  //       went to war).
+  //   (3) PER-TURN EFFECT: the FULL active lists (not just this turn's
+  //       declares) each apply their deterministic effect this turn —
+  //       trade: both parties' economy up a little; embargo: the
+  //       target's economy down a little — clamped, mirrored to the
+  //       owning nations' regions, and re-derived like the hybrid dip.
+  // Additive only: declares add, lifts remove, and nothing else (not even
+  // a war) mutates the lists besides the suspension above.
+  applyEconomyOps(next, result.economy);
+  suspendEconomyOnWar(next);
+  applyEconomyEffects(next, geoOf);
+
   // --- Map markers (v0.27, #44) ---
   //
   // Markers are anchored to a region key and are processed against the FINAL
@@ -2058,6 +2291,10 @@ export async function runTurn(opts: {
     markers,
     wars,
     relations,
+    // (v0.35.0, #58) the active trade / embargo lists, so the model can
+    // reference — and `lift` — what is currently in force.
+    state.trades,
+    state.embargoes,
   );
   const nudge =
     'Your previous output was invalid. Respond with ONLY the JSON object described above for this batch — no prose, no fences.';
@@ -2113,6 +2350,7 @@ export async function runTurn(opts: {
       takeovers: [],
       wars: { declare: [], end: [] },
       hybrid: { ops: [] },
+      economy: { trade: [], embargo: [] },
       markers: { add: [], remove: [] },
     };
   }

server/index.ts

@@ -182,6 +182,10 @@ app.post('/api/games', (req: Request, res) => {
     // (any preset-level `war` relation stays a bare/implicit one, not an
     // entity — see syncWarRelations).
     wars: [],
+    // (v0.35.0, #58) No active trades or embargoes on a fresh game; the LLM
+    // declares (and lifts) them over time via TurnResult.economy.
+    trades: [],
+    embargoes: [],
   };
   // v0.19 (#16 P1): expand each nation's ISO_A3 country list to the region keys
   // of all its sub-regions, so ownership (and the choropleth) is at region

server/map.test.ts

@@ -54,6 +54,9 @@ const state: GameState = {
   regionStats: {},
   // (v0.33.0, #56) the map is ownership-only; wars are unused here.
   wars: [],
+  // (v0.35.0, #58) the map is ownership-only; trades/embargoes are unused here.
+  trades: [],
+  embargoes: [],
 };
 
 // The RegionMap built from the fixture: the authoritative region key → owner source.

server/protocol.test.ts

@@ -42,6 +42,8 @@ function mkState(
     markers: [],
     regionStats: {} as GameState['regionStats'],
     wars: [],
+    trades: [],
+    embargoes: [],
   };
   if (regionStats !== undefined) base.regionStats = regionStats as GameState['regionStats'];
   else delete (base as { regionStats?: unknown }).regionStats; // simulate a legacy row

server/regions.test.ts

@@ -111,6 +111,9 @@ describe('regions (region-key loader, v0.19 #16 P1)', () => {
       // (v0.28, #46) unused here (allTerritoryKeys is ownership-only).
       regionStats: {},
       wars: [],
+      // (v0.35.0, #58) unused here (allTerritoryKeys is ownership-only).
+      trades: [],
+      embargoes: [],
     };
     // 16 GBR sub-regions + 42 FRA sub-regions, no overlap between the two.
     expect(allTerritoryKeys(state).size).toBe(58);

server/stub.ts

@@ -52,6 +52,21 @@ export interface StubPayload {
    * deterministicTurn), so the hybrid path is covered by unit tests only.
    */
   relations?: Record<string, RelationStatus>;
+  /**
+   * (v0.35.0, #58) The currently active bilateral trade agreements
+   * (`{ a, b }` nation-id pairs), emitted by the engine's user prompt. The
+   * stub ignores this field — it never declares, lifts or suspends a trade
+   * (see deterministicTurn), so the trade path is covered by unit tests only.
+   */
+  trades?: Array<{ a: string; b: string }>;
+  /**
+   * (v0.35.0, #58) The currently active unilateral embargoes
+   * (`{ from, target }` nation-id pairs), emitted by the engine's user
+   * prompt. The stub ignores this field — it never imposes, lifts or
+   * suspends an embargo (see deterministicTurn), so the embargo path is
+   * covered by unit tests only.
+   */
+  embargoes?: Array<{ from: string; target: string }>;
 }
 
 function truncate(s: string, n: number): string {
@@ -103,6 +118,11 @@ function truncate(s: string, n: number): string {
  * (v0.34.0, #57) The stub likewise NEVER runs a hybrid / covert op (it always
  * returns `hybrid: { ops: [] }`) — the hybrid-war path is covered by unit
  * tests only, keeping the e2e assertions untouched.
+ *
+ * (v0.35.0, #58) The stub likewise NEVER declares, lifts or suspends a trade
+ * or an embargo (it always returns `economy: { trade: [], embargo: [] }`) —
+ * the trade & embargo economy path is covered by unit tests only, keeping
+ * the e2e assertions untouched.
  */
 export function deterministicTurn(p: StubPayload): TurnResult {
   const state = p.state;
@@ -172,6 +192,7 @@ export function deterministicTurn(p: StubPayload): TurnResult {
     takeovers: [], // the stub never performs a takeover (see doc comment)
     wars: { declare: [], end: [] }, // the stub never declares/ends wars (see doc comment)
     hybrid: { ops: [] }, // the stub never runs hybrid/covert ops (see doc comment)
+    economy: { trade: [], embargo: [] }, // the stub never touches trades/embargoes (see doc comment)
     markers: { add: [], remove: [] }, // the stub never touches markers (see doc comment)
   };
 }

shared/protocol.ts

@@ -363,6 +363,59 @@ export interface HybridOp {
   outcome?: 'success' | 'exposed';
 }
 
+// --- Trade & embargo ops (v0.35.0, #58) --------------------------------------
+
+/**
+ * (v0.35.0, #58) A bilateral TRADE op in `TurnResult.economy.trade`: `a` and
+ * `b` are the two parties (each a nation's id or unique name — resolved by
+ * the engine's `resolveNationRef`; a pair that resolves to the same nation,
+ * or contains an unknown/ambiguous ref, is dropped defensively). Without
+ * `lift` the op DECLARES the agreement (idempotent — an already-active
+ * agreement is not duplicated); `lift: true` ENDS it.
+ */
+export interface EconomyTradeOp {
+  /** First party's id or unique name. */
+  a: string;
+  /** Second party's id or unique name (distinct from `a` after resolution). */
+  b: string;
+  /** `true` → end this bilateral trade; default `false` = declare it. */
+  lift?: boolean;
+}
+
+/**
+ * (v0.35.0, #58) A unilateral EMBARGO op in `TurnResult.economy.embargo`:
+ * `from` blocks trade with `target` (each a nation's id or unique name —
+ * resolved by `resolveNationRef`; an unknown/ambiguous ref or
+ * `from === target` is dropped defensively). Without `lift` the op imposes
+ * the embargo (idempotent — an already-active one is not duplicated);
+ * `lift: true` LIFTS it.
+ */
+export interface EconomyEmbargoOp {
+  /** The imposing nation's id or unique name. */
+  from: string;
+  /** The embargoed nation's id or unique name (distinct from `from`). */
+  target: string;
+  /** `true` → lift this embargo; default `false` = impose it. */
+  lift?: boolean;
+}
+
+/**
+ * (v0.35.0, #58) The turn's trade-and-embargo operations, nested under
+ * `TurnResult.economy`. Both arrays are required and default to `[]`. The
+ * engine applies the ops to `GameState.trades` / `GameState.embargoes`
+ * (add = declare/impose, remove = lift) and, on every committed turn, applies
+ * the per-turn economic effect of the FULL active lists (trade: both
+ * parties' economy up a little; embargo: the target's economy down a
+ * little). Active trades/embargoes between nations on opposite sides of an
+ * active war (v0.33, #56) are suspended (removed) automatically.
+ */
+export interface EconomyOps {
+  /** Bilateral trades (declare or lift). */
+  trade: EconomyTradeOp[];
+  /** Unilateral embargoes (impose or lift). */
+  embargo: EconomyEmbargoOp[];
+}
+
 /** The exact JSON object the world-simulator LLM must return for a turn. */
 export interface TurnResult {
   date: string;
@@ -439,6 +492,20 @@ export interface TurnResult {
    * `{ ops: [] }`).
    */
   hybrid: { ops: HybridOp[] };
+  /**
+   * (v0.35.0, #58) Trade and embargo ops — the economy layer. `trade`
+   * declares (or, with `lift: true`, ends) bilateral trade agreements
+   * between two nations; `embargo` imposes (or, with `lift: true`, lifts)
+   * a unilateral embargo on a target. Both arrays are required and default
+   * to `[]`. Applied directly by `applyTurnResult` (add to / remove from
+   * `GameState.trades` / `GameState.embargoes`), and the per-turn economic
+   * effect of the FULL active lists is applied on every committed turn (a
+   * trade lifts both parties' economy a little; an embargo lowers the
+   * target's economy a little — clamped, deterministic). Active
+   * trades/embargoes between nations on opposite sides of an active war are
+   * suspended automatically.
+   */
+  economy: EconomyOps;
   /**
    * (v0.27, #44) Map-marker ops this turn. `add` places new named markers
    * (the engine positions each at its region's centroid + a small

shared/scenario.ts

@@ -456,6 +456,9 @@ export function worldDraftToGameState(
     // (v0.33.0, #56) No wars on a fresh (dynamic) game; any preset-level `war`
     // relation stays a bare/implicit one, not an entity (see syncWarRelations).
     wars: [],
+    // (v0.35.0, #58) No trades/embargoes on a fresh (dynamic) game.
+    trades: [],
+    embargoes: [],
   };
   return state;
 }

shared/types.ts

@@ -143,6 +143,37 @@ export interface MapMarker {
   placedTurn: number;
 }
 
+/**
+ * (v0.35.0, #58) An active BILATERAL TRADE agreement between two distinct
+ * nations. Declared by the LLM via `TurnResult.economy.trade` (a no-`lift`
+ * op) and ended by a `lift: true` op; while active it yields a small,
+ * deterministic economy gain to BOTH parties every committed turn. The
+ * engine suspends (removes) the trade automatically when the two parties end
+ * up on opposite sides of an active war (v0.33, #56).
+ */
+export interface TradeAgreement {
+  /** First party's nation id. */
+  a: string;
+  /** Second party's nation id (distinct from `a`; the pair is symmetric). */
+  b: string;
+}
+
+/**
+ * (v0.35.0, #58) An active UNILATERAL EMBARGO: `from` blocks trade with
+ * `target` (which must differ from `from`). Declared by the LLM via
+ * `TurnResult.economy.embargo` (a no-`lift` op) and lifted by a `lift: true`
+ * op; while active it applies a small, deterministic economy dip to the
+ * TARGET only, every committed turn. The engine suspends (removes) the
+ * embargo automatically when the two nations end up on opposite sides of an
+ * active war (v0.33, #56).
+ */
+export interface Embargo {
+  /** The imposing nation's id. */
+  from: string;
+  /** The embargoed nation's id (distinct from `from`). */
+  target: string;
+}
+
 /**
  * (v0.33.0, #56) A first-class **war** — a named, ongoing armed conflict
  * between two or more nations. Unlike the boolean `war` relation (which a
@@ -303,6 +334,28 @@ export interface GameState {
    * additive, no data wipe.
    */
   wars: War[];
+  /**
+   * (v0.35.0, #58) Active bilateral trade agreements (see {@link TradeAgreement}):
+   * declared/ended by a turn's `economy.trade` ops (a no-`lift` op declares,
+   * `lift: true` ends). Every committed turn the engine applies a small,
+   * deterministic economy gain to BOTH parties of each active agreement, and
+   * suspends (removes) any agreement whose two parties are on opposite sides
+   * of an active war (v0.33, #56). Always `[]` on a fresh game; rows saved
+   * before v0.35 load with this defaulted to `[]` (see server/db.ts) —
+   * additive, no data wipe.
+   */
+  trades: TradeAgreement[];
+  /**
+   * (v0.35.0, #58) Active unilateral embargoes (see {@link Embargo}):
+   * imposed/lifted by a turn's `economy.embargo` ops (a no-`lift` op imposes,
+   * `lift: true` lifts). Every committed turn the engine applies a small,
+   * deterministic economy dip to each embargo's TARGET only, and suspends
+   * (removes) any embargo whose two nations are on opposite sides of an
+   * active war (v0.33, #56). Always `[]` on a fresh game; rows saved before
+   * v0.35 load with this defaulted to `[]` (see server/db.ts) — additive,
+   * no data wipe.
+   */
+  embargoes: Embargo[];
 }
 
 /**