# The exchange

> Items for items at a fixed rate, in the game's own trading window - a coin bank, say - opened by a command or a figure players click. New in 0.3, off by default.

Source: https://stygion.eu/docs/keystone/exchange
Updated: 2026-10-25

New in 0.3, module `exchange`, off by default. An exchange swaps items for items at a fixed rate in the game's own trading window, which every player already knows. Typical use: a coin bank that changes small coins for big ones and back.

## Setting it up (`exchange.toml`)

- `items`: the server's own items, the same lines as `crates.items`: `obol minecraft:debug_stick model=74001 look=stygion:coin_obol colour=#e8dcc0 Obol | The ferryman's fare.` An item with a `look` carries Keystone's mark, and **only marked items are taken in**, so a renamed copy is worth nothing.
- `trades`: what each exchange swaps, a line each: `<exchange> | <count> <item> -> <count> <item>`, with ids from `items` or any game item id. `bank | 8 obol -> 1 ember`, `bank | 1 ember -> 8 obol`.
- `titles`: the window's title per exchange (`bank | &#ffca36&lBank`), `[en]…[cs]…` allowed.
- `command`: the command that opens it, `/exchange [name]` by default; write `bank` to make it `/bank`. A restart applies a new name.
- `figures`: figures that open an exchange when clicked, kept standing by Keystone (put back if gone, moved back if pushed, never hurt, never picked up): `bank | minecraft:overworld | 209.5 131.0625 43.5 | 69 | Banker` (exchange, world, position, facing, name).
- `range`: how near a figure of the same exchange the command works, in blocks; 0 works anywhere.

Every opening is a window of its own with nothing shared between players. Permission `keystone.exchange` (everybody by default). `GET /v1/exchange` (scope `status.read`) lists the exchanges and their trades.