Trade station

A Trade station is a Station subtype that acts as a cross-faction marketplace. Unlike a Production factory, a trade station does not produce wares — it lists buy and sell offers from other stations the player has trade-licence access to. Players use trade stations as central trading hubs; modders rely on them as “find any trade for X” lookup points.

This page documents Trade-station-specific behavior. For all general station behavior (creation, ownership, modules, hull, dockingbays, events), see the parent Station page.

Identification

Flag	Meaning
.istradestation	This station is a trade station
(no .isplannedtradestation)	Vanilla treats trade station as a deferred flag — set on completion. To detect during construction, fall back to .macro macro-name check

Vanilla note: a station with .istradestation=true is mutually exclusive with shipyard / wharf / equipment-dock / defence-station roles in vanilla content. Filter logic frequently uses not .istradestation as “this is a production station” (vanilla gmc_retrieve_dead_drop.xml:2310).

Properties (trade-station-relevant)

All accessors live on the parent station datatype (scriptproperties.xml:848). There is no separate tradestation datatype.

Property	Type	Description
.istradestation	bool	Currently a trade station
.products	warelist	What this station accepts as products (typically empty for trade station — they don’t produce)
.tradewares	warelist	Wares that are traded here (bought and resold; neither product nor resource)
.buyprices	table	Per-ware buy prices (table form)
.sellprices	table	Per-ware sell prices
.hastradesubscription	bool	Player has trade-offer subscription (sees all offers at this station)
.haspermanenttradesubscription	bool	Permanent subscription owned (vs trial / temporary)

Differentiating trade station from production / equipment

<!-- Pure trade station -->
<do_if value="$Station.istradestation
    and not $Station.isshipyard
    and not $Station.iswharf">
    <!-- marketplace, no production / no shipbuilding -->
</do_if>

<!-- Production station (NOT a trade station) -->
<do_if value="not $Station.istradestation
    and not $Station.isshipyard
    and not $Station.iswharf
    and not $Station.isequipmentdock
    and not $Station.isdefencestation
    and not $Station.isfactionheadquarters
    and $Station.resources.count gt 0">
    <!-- regular production factory — has consumable resources -->
</do_if>

The second pattern is the canonical “is this a normal production station” filter used by mods that target the player’s economic backbone. Vanilla gmc_retrieve_dead_drop.xml:2310 uses the inverted check.

Common trade-station patterns

”Find the nearest trade station that sells this ware"

<find_station_by_true_owner name="$Candidates"
    space="player.galaxy"
    multiple="true"
    sortbydistanceto="player.ship"/>

<set_value name="$found" exact="null"/>

<do_for_each name="$station" in="$Candidates">
    <do_if value="$station.istradestation
        and $station.sellprice.{$ware} gt 0
        and $station.cargo.{$ware}.amount gt 0">
        <set_value name="$found" exact="$station"/>
        <break/>
    </do_if>
</do_for_each>

"Subscribe the player to trade offers at a station”

Use the vanilla Subscription action — trade subscription gating is separate from station type. The trade station flag only controls which offers are visible at the station, not the subscription action itself.

”Did the player buy a trade station?”

A trade station doesn’t have a dedicated construction event. Watch the station’s .istradestation transition via NPC instantiation or save-load events. The simplest practical pattern is to listen for event_object_changed_owner and then check .istradestation on the new player-owned station.

Construction macros

Trade stations are constructed using:

• Group: tradestation_<faction_3-letter-code> (e.g. tradestation_arg) in libraries/stationgroups.xml.
• Plan: e.g. arg_tradestation in libraries/constructionplans.xml.

Trade stations typically contain a trade module and many storage modules but no production modules. Modding a new trade station means picking modules accordingly.

Common gotchas

• ⚠ Trade stations don’t produce. .products is typically empty (or only contains pass-through tradewares). Don’t expect a recipe-aware iteration to find anything.
• ⚠ .tradewares vs .products. Tradewares are the “buy from one station, sell to another” wares the trade station handles; .products is for actually-produced wares. Most modder logic wants .tradewares.
• ⚠ .istradestation is mutually exclusive with shipyard / wharf / equipment-dock in vanilla. But there’s no engine enforcement — modded content could violate this. Don’t rely on the exclusion for correctness.
• ⚠ Trade stations don’t appear in find_station results without space=. Same as all stations — space= is required.
• ⚠ Trade offers visible at a trade station depend on player licences. .hastradesubscription controls visibility, not whether offers exist. Two players with different licences see different offers at the same trade station.
• ⚠ The “normal production station” filter is not .istradestation and not .isshipyard and not .iswharf .... Vanilla maintains this idiom — copy it rather than reinventing, since new station-type flags may be added in DLC.

Architectural context

• How factions decide where to build trade stations: Architectural overview Faction economy — trade stations are placed at high-connectivity sectors (lots of gates) and high-economy clusters.
• Trade offer lifecycle: Architectural overview Trade offer lifecycle — buy/sell offer creation at producing stations, propagation to trade stations via subscriptions.
• Subscription mechanics: Architectural overview Subscriptions — how .hastradesubscription is set, trial vs permanent, satellite-based vs purchased.

Related

• Station — parent abstraction (all general properties/actions live there).
• Shipyard — sibling subtype, builds L/XL ships.
• Wharf — sibling subtype, builds S/M ships.
• Equipment dock — sibling subtype, installs equipment.
• Production factory — sibling subtype, actually produces wares.
• Faction — owner; relations gate visible trade offers.
• Ware — what is traded.
• Trade offer — the offers visible at a trade station.
• Subscription — how players unlock visibility.

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Pattern — IS-A subtype page

Same pattern as Shipyard / Wharf / Equipment dock — this page only documents Trade-station-specific behavior. General station behavior lives on Station.