Phase 7: PlayerVendorSale core event + subscriber

The one non-drop-in piece. Player-vendor purchases raise no EventSink, so the
sale is invisible to subscription. Two git-format core patches add a
PlayerVendorSale event and raise it at the committed sale in
PlayerVendorBuyGump.OnResponse (right after HoldGold +=), where buyer, vendor
owner, item, price, and commission are all in scope. The subscriber
BridgeVendorSale emits vendor.sale.

All three are a coupled unit. The subscriber references PlayerVendorSaleEventArgs,
which does not exist until the EventSink patch is applied, so it lives in patches/
not overlay/ -- shipping it in overlay would break the build on any unpatched
install. patches/README.md documents applying the unit; both patches verified
with git apply --check against stock ServUO 57.4. This is the first phase that
rebuilds the core (ServUO.exe), not just Scripts.dll.

vendor.sale carries buyer and vendor-owner accounts, both present and distinct,
which is the pair that flags gold-laundering when they match -- richer than the
ownerless NPC ValidVendor* events, and on a committed sale rather than a
validation stage.

Verified with a probe firing the event on real seeded-vendor data: vendor.sale
emitted with buyerAcct=seed_001, ownerAcct=seed_000, Longsword, price 69819. The
probe proves the event, args, subscriber, and payload; the literal gump call site
firing on a real purchase needs a live buyer with a NetState and is confirmed by
an in-game buy. Evidence in docs/PLAN.md §17.

This completes every phase on the ServUO side. Phases 0-6 are drop-in (overlay/);
7 is patches/. Cheat signals are folded into existing streams (fastwalk, audit,
vendor.sale), not a separate phase. Remaining work is the Rust sidecar.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

patches/BridgeVendorSale.cs

@@ -0,0 +1,83 @@
+using System;
+
+using Server;
+using Server.Accounting;
+using Server.Custom.Bridge;
+
+namespace Server.Custom.Bridge
+{
+    /// <summary>
+    ///     Subscribes to the PlayerVendorSale event added by the Phase 7 core patches. This file is
+    ///     part of that coupled unit and is NOT in overlay/, because it references
+    ///     PlayerVendorSaleEventArgs, which does not exist until the EventSink patch is applied —
+    ///     shipping it in overlay/ would break the build on any install without the patch.
+    ///
+    ///     Deploy: apply patches/playervendor-sale-*.patch, then copy this file to
+    ///     Scripts/Custom/Bridge/BridgeVendorSale.cs.
+    ///
+    ///     The event fires at the committed sale (PlayerVendorBuyGump.OnResponse), on the Core
+    ///     thread, with buyer, vendor owner, item, price, and commission all in scope — richer than
+    ///     the NPC ValidVendor* events (which lack owner and commission) and, unlike them, on a
+    ///     committed sale rather than a validation stage. It is the backbone of the cheat-detection
+    ///     feed: same-account buyer≈owner is gold laundering, off-market prices and burst patterns
+    ///     are visible to the sidecar.
+    /// </summary>
+    public static class BridgeVendorSale
+    {
+        public static void Initialize()
+        {
+            if (!BridgeConfig.Enabled)
+                return;
+
+            EventSink.PlayerVendorSale += OnPlayerVendorSale;
+            Console.WriteLine("[Bridge] player-vendor sale stream attached");
+        }
+
+        private static void OnPlayerVendorSale(PlayerVendorSaleEventArgs e)
+        {
+            try
+            {
+                var sb = BridgeJson.Begin("vendor.sale")
+                    .Bool("committed", true);
+
+                // Buyer
+                if (e.Buyer != null)
+                {
+                    sb.Ser("buyerSerial", e.Buyer.Serial);
+                    var ba = e.Buyer.Account as Account;
+                    if (ba != null)
+                        sb.Str("buyerAcct", ba.Username);
+                }
+
+                // Vendor owner — the player who actually profits.
+                if (e.Owner != null)
+                {
+                    sb.Ser("ownerSerial", e.Owner.Serial);
+                    var oa = e.Owner.Account as Account;
+                    if (oa != null)
+                        sb.Str("ownerAcct", oa.Username);
+                }
+
+                if (e.Vendor != null)
+                    sb.Ser("vendorSerial", e.Vendor.Serial);
+
+                if (e.Item != null)
+                {
+                    sb.Ser("itemSerial", e.Item.Serial);
+                    sb.Str("itemType", e.Item.GetType().Name);
+                    sb.Num("itemId", e.Item.ItemID);
+                    sb.Num("amount", e.Item.Amount);
+                }
+
+                sb.Num("price", e.Price);
+                sb.Num("commission", e.Commission);
+
+                BridgeLink.Emit(sb.End());
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine("[Bridge] vendor.sale handler threw: {0}", ex.Message);
+            }
+        }
+    }
+}

patches/README.md

@@ -9,20 +9,28 @@ git apply --check patches/<name>.patch   # dry run
 git apply         patches/<name>.patch
 ```
 
-## Current
+## Phase 7 — player-vendor sale (a coupled unit)
 
-| Patch | Phase | File | Why |
+Player-vendor purchases raise **no** EventSink. `ValidVendorPurchase` / `ValidVendorSell` cover NPC vendors only. The commit point is `PlayerVendorBuyGump.OnResponse`, the only place where buyer, vendor **owner**, price, and commission are all in scope — exactly what cheat detection needs. See `docs/PLAN.md` §6.
-|-------|:-----:|------|-----|
-| _(none yet)_ | | | |
 
-## Planned
+This is the one non-drop-in piece. Apply all three together:
 
-| Patch | Phase | File | Why |
+| Item | Target | What |
-|-------|:-----:|------|-----|
+|------|--------|------|
-| `playervendor-sale-event` | 7 | `Server/EventSink.cs` | Declare `PlayerVendorSale`, `InvokePlayerVendorSale`, `PlayerVendorSaleEventArgs { Buyer, Vendor, Owner, Item, Price, Commission }`. |
+| `playervendor-sale-eventsink.patch` | `Server/EventSink.cs` | Adds the `PlayerVendorSale` delegate, `PlayerVendorSaleEventArgs { Buyer, Vendor, Owner, Item, Price, Commission }`, the event field, and `InvokePlayerVendorSale`. |
-| `playervendor-sale-event` | 7 | `Scripts/Gumps/PlayerVendorGumps.cs` | One `InvokePlayerVendorSale` call after the `HoldGold +=` at line 96, where the sale commits. |
+| `playervendor-sale-gump.patch` | `Scripts/Gumps/PlayerVendorGumps.cs` | One `InvokePlayerVendorSale(...)` call right after the committed `HoldGold +=`. |
+| `BridgeVendorSale.cs` | copy to `Scripts/Custom/Bridge/` | The subscriber that emits `vendor.sale`. **Not** in `overlay/` because it references `PlayerVendorSaleEventArgs`, which does not exist until the EventSink patch is applied — shipping it in overlay would break the build on any unpatched install. |
 
-Player-vendor purchases raise **no** EventSink. `ValidVendorPurchase` / `ValidVendorSell` cover NPC vendors only. The commit point is `PlayerVendorBuyGump.OnResponse`, and it is the only place where buyer, vendor **owner**, price, and commission are all in scope — which is exactly what cheat detection needs. See `docs/PLAN.md` §6.
+```bash
+cd <servuo root>
+git apply --check patches/playervendor-sale-eventsink.patch patches/playervendor-sale-gump.patch  # dry run
+git apply         patches/playervendor-sale-eventsink.patch patches/playervendor-sale-gump.patch
+cp patches/BridgeVendorSale.cs Scripts/Custom/Bridge/BridgeVendorSale.cs
+```
+
+Both patches are `git`-format and verified with `git apply --check` against stock ServUO 57.4. Modifying `EventSink.cs` means the **core** rebuilds, so `ScriptCompiler`'s dynamic script build is not enough — rebuild the solution (`dotnet build ServUO.sln`) or the server binary.
+
+Not applicable to a non-git shard? `git apply` works in a plain directory too. If `patch` is used instead, note the core files are CRLF; use `patch --binary`.
 
 ## Note on `Scripts.csproj`
 

patches/playervendor-sale-eventsink.patch

@@ -0,0 +1,66 @@
+diff --git a/Server/EventSink.cs b/Server/EventSink.cs
+index d30788f..1da2667 100644
+--- a/Server/EventSink.cs
++++ b/Server/EventSink.cs
+@@ -171,6 +171,8 @@ namespace Server
+ 
+     public delegate void ValidVendorSellEventHandler(ValidVendorSellEventArgs e);
+ 
++    public delegate void PlayerVendorSaleEventHandler(PlayerVendorSaleEventArgs e);
++
+     public delegate void CorpseLootEventHandler(CorpseLootEventArgs e);
+ 
+     public delegate void RepairItemEventHandler(RepairItemEventArgs e);
+@@ -1521,6 +1523,29 @@ namespace Server
+         }
+     }
+ 
++    // Player-vendor purchases raise no other EventSink. This fires at the committed sale in
++    // PlayerVendorBuyGump.OnResponse, where buyer, vendor owner, item, price, and commission
++    // are all in scope -- the data the bridge's cheat-detection feed needs.
++    public class PlayerVendorSaleEventArgs : EventArgs
++    {
++        public Mobile Buyer { get; set; }
++        public Mobile Vendor { get; set; }
++        public Mobile Owner { get; set; }
++        public Item Item { get; set; }
++        public int Price { get; set; }
++        public int Commission { get; set; }
++
++        public PlayerVendorSaleEventArgs(Mobile buyer, Mobile vendor, Mobile owner, Item item, int price, int commission)
++        {
++            Buyer = buyer;
++            Vendor = vendor;
++            Owner = owner;
++            Item = item;
++            Price = price;
++            Commission = commission;
++        }
++    }
++
+     public class CorpseLootEventArgs : EventArgs
+     {
+         public Mobile Mobile { get; set; }
+@@ -1771,6 +1796,7 @@ namespace Server
+         public static event TameCreatureEventHandler TameCreature;
+         public static event ValidVendorPurchaseEventHandler ValidVendorPurchase;
+         public static event ValidVendorSellEventHandler ValidVendorSell;
++        public static event PlayerVendorSaleEventHandler PlayerVendorSale;
+         public static event CorpseLootEventHandler CorpseLoot;
+         public static event RepairItemEventHandler RepairItem;
+         public static event AlterItemEventHandler AlterItem;
+@@ -2416,6 +2442,14 @@ namespace Server
+             }
+         }
+ 
++        public static void InvokePlayerVendorSale(PlayerVendorSaleEventArgs e)
++        {
++            if (PlayerVendorSale != null)
++            {
++                PlayerVendorSale(e);
++            }
++        }
++
+         public static void InvokeCorpseLoot(CorpseLootEventArgs e)
+         {
+             if (CorpseLoot != null)

patches/playervendor-sale-gump.patch

@@ -0,0 +1,15 @@
+diff --git a/Scripts/Gumps/PlayerVendorGumps.cs b/Scripts/Gumps/PlayerVendorGumps.cs
+index 049aae6..f1b30d2 100644
+--- a/Scripts/Gumps/PlayerVendorGumps.cs
++++ b/Scripts/Gumps/PlayerVendorGumps.cs
+@@ -95,6 +95,10 @@ namespace Server.Gumps
+ 
+                     m_Vendor.HoldGold += m_VI.Price - commission;
+ 
++                    // uo-link: the only committed-sale hook for player vendors (no EventSink exists).
++                    EventSink.InvokePlayerVendorSale(
++                        new PlayerVendorSaleEventArgs(from, m_Vendor, m_Vendor.Owner, m_VI.Item, m_VI.Price, commission));
++
+                     from.SendLocalizedMessage(503201); // You take the item.
+                 }
+             }

tools/scaffolding/BridgeVendorSaleProbe.cs

@@ -0,0 +1,104 @@
+using System;
+
+using Server.Accounting;
+using Server.Items;
+using Server.Mobiles;
+
+namespace Server.Custom
+{
+    /// <summary>
+    ///     Fires PlayerVendorSale with real seeded-vendor data to prove the full chain: the
+    ///     EventSink event added by the Phase 7 patch, its args, the subscriber, and the vendor.sale
+    ///     JSON. It does NOT exercise the gump call site (that needs a live buyer with a NetState) —
+    ///     the hook line is placed at the committed-sale point in PlayerVendorBuyGump.OnResponse and
+    ///     is verified by a real in-game purchase.
+    ///
+    ///     Test scaffolding. Never deployed. Read-only (invokes an event; changes no world state).
+    /// </summary>
+    public static class BridgeVendorSaleProbe
+    {
+        public static void Initialize()
+        {
+            if (Config.Get("Bridge.VendorSaleProbeOnStart", false))
+                EventSink.ServerStarted += () => Timer.DelayCall(TimeSpan.FromSeconds(4.0), Run);
+        }
+
+        private static void Run()
+        {
+            try
+            {
+                var vendors = PlayerVendor.PlayerVendors;
+
+                if (vendors == null || vendors.Count == 0)
+                {
+                    Console.WriteLine("[VendorSaleProbe] no player vendors; seed the world first");
+                    return;
+                }
+
+                // A real seeded vendor, its owner, and one of its actual priced items.
+                PlayerVendor vendor = null;
+                Item item = null;
+                int price = 0;
+
+                foreach (var v in vendors)
+                {
+                    if (v == null || v.Deleted || v.Owner == null || v.Backpack == null)
+                        continue;
+
+                    foreach (var it in v.Backpack.Items)
+                    {
+                        var vi = v.GetVendorItem(it);
+                        if (vi != null)
+                        {
+                            vendor = v; item = it; price = vi.Price;
+                            break;
+                        }
+                    }
+
+                    if (vendor != null)
+                        break;
+                }
+
+                if (vendor == null)
+                {
+                    Console.WriteLine("[VendorSaleProbe] no vendor with a priced item found");
+                    return;
+                }
+
+                // A buyer on a DIFFERENT account than the owner, so buyerAcct != ownerAcct.
+                Mobile buyer = null;
+                foreach (Account a in Accounting.Accounts.GetAccounts())
+                {
+                    if (!a.Username.StartsWith("seed_", StringComparison.Ordinal))
+                        continue;
+
+                    var pm = a[0] as PlayerMobile;
+                    if (pm != null && pm != vendor.Owner &&
+                        !(vendor.Owner != null && vendor.Owner.Account == a))
+                    {
+                        buyer = pm;
+                        break;
+                    }
+                }
+
+                int commission = 0;
+                if (vendor.IsCommission)
+                    commission = (int)(price * (vendor.CommissionPerc / 100));
+
+                Console.WriteLine("[VendorSaleProbe] firing PlayerVendorSale: buyer={0} owner={1} item={2} price={3} commission={4}",
+                    buyer == null ? "?" : buyer.Name,
+                    vendor.Owner == null ? "?" : vendor.Owner.Name,
+                    item.GetType().Name, price, commission);
+
+                EventSink.InvokePlayerVendorSale(
+                    new PlayerVendorSaleEventArgs(buyer, vendor, vendor.Owner, item, price, commission));
+
+                Console.WriteLine("[VendorSaleProbe] done; watch for vendor.sale");
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine("[VendorSaleProbe] FAILED: " + ex);
+            }
+        }
+    }
+}

tools/scaffolding/README.md

@@ -12,6 +12,7 @@ These two scripts produced the measured budget in `docs/PLAN.md` §1. They are k
 | `BridgeSweepProbe.cs` | `Scripts/Custom/BridgeSweepProbe.cs` | Bumps one seeded house's decay stage after baseline so the decay sweep's transition detection can be observed without waiting a real IDOC stage. Flag: `SweepProbeOnStart`. Pair with short `*SweepSeconds` overrides. |
 | `BridgeLinkProbe.cs` | `Scripts/Custom/BridgeLinkProbe.cs` | Triggers `[link` for seed_001 without a client, then saves so the `WebsiteUserId` tag reaches `accounts.xml`. Flag: `LinkProbeOnStart`. Pair with a sidecar that reads the code and sends `link.confirm`. |
 | `BridgeCrierProbe.cs` | `Scripts/Custom/BridgeCrierProbe.cs` | Logs the global town-crier entry list every 3s so `towncrier.add` / `remove` can be seen landing in game state. Flag: `CrierProbeOnStart`. |
+| `BridgeVendorSaleProbe.cs` | `Scripts/Custom/BridgeVendorSaleProbe.cs` | Fires `PlayerVendorSale` (Phase 7) with real seeded-vendor data so `vendor.sale` can be verified without a live buy. Requires the Phase 7 patches applied. Flag: `VendorSaleProbeOnStart`. |
 
 ## Deploy overwrites Bridge.cfg