Add HoudiniSwap prototype swap plugin

Prototype CEX swap plugin for HoudiniSwap built on the v2 partner API:
resolve Edge assets to Houdini token ids via GET /tokens, fetch quotes,
pick the best private route, and create the exchange. Credentials are wired
through testconfig.json as { apiKey, apiSecret }.

Includes a standalone acceptance harness that drives BTC->ETH and ETH->USDC
quote plus order creation, caching every API response to disk so repeat runs
replay from fixtures and stay inside the free-tier rate budget.

Author: j0ntz

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- added: HoudiniSwap prototype swap plugin (private CEX routing) with a cached acceptance harness.
+
 ## 2.46.0 (2026-04-18)
 
 - changed: Migrate Thorchain swap endpoints off NineRealms (thornode, tx tracker, Midgard sync fallback).

src/index.ts

@@ -6,6 +6,7 @@ import { makeChangeHeroPlugin } from './swap/central/changehero'
 import { makeChangeNowPlugin } from './swap/central/changenow'
 import { makeExolixPlugin } from './swap/central/exolix'
 import { makeGodexPlugin } from './swap/central/godex'
+import { makeHoudiniPlugin } from './swap/central/houdini'
 import { makeLetsExchangePlugin } from './swap/central/letsexchange'
 import { makeNexchangePlugin } from './swap/central/nexchange'
 import { makeSideshiftPlugin } from './swap/central/sideshift'
@@ -36,6 +37,7 @@ const plugins = {
   cosmosibc: makeCosmosIbcPlugin,
   exolix: makeExolixPlugin,
   godex: makeGodexPlugin,
+  houdini: makeHoudiniPlugin,
   letsexchange: makeLetsExchangePlugin,
   lifi: makeLifiPlugin,
   nexchange: makeNexchangePlugin,

src/mappings/houdini.ts

@@ -0,0 +1,97 @@
+/**
+ * Maps Edge `EdgeCurrencyPluginId` -> HoudiniSwap chain `shortName` (v2 `GET /chains`),
+ * or `null` when Houdini has no compatible non-memo chain for that asset.
+ *
+ * Hand-authored for the HoudiniSwap prototype from the Phase 1 coverage matrix.
+ * Memo-required chains (XRP/XLM/Cosmos-family) are intentionally `null` because the
+ * prototype does not yet plumb a deposit memo / `destinationTag`.
+ */
+
+import { EdgeCurrencyPluginId } from '../util/edgeCurrencyPluginIds'
+
+export const houdini = new Map<EdgeCurrencyPluginId, string | null>()
+houdini.set('abstract', null)
+houdini.set('algorand', 'algorand')
+houdini.set('amoy', null)
+houdini.set('arbitrum', 'arbitrum')
+houdini.set('avalanche', 'avalanche')
+houdini.set('axelar', null)
+houdini.set('badcoin', null)
+houdini.set('base', 'base')
+houdini.set('binance', null)
+houdini.set('binancesmartchain', 'bsc')
+houdini.set('bitcoin', 'bitcoin')
+houdini.set('bitcoincash', 'bitcoincash')
+houdini.set('bitcoincashtestnet', null)
+houdini.set('bitcoingold', null)
+houdini.set('bitcoingoldtestnet', null)
+houdini.set('bitcoinsv', 'bsv')
+houdini.set('bitcointestnet', null)
+houdini.set('bitcointestnet4', null)
+houdini.set('bobevm', null)
+houdini.set('botanix', null)
+houdini.set('calibration', null)
+houdini.set('cardano', 'cardano')
+houdini.set('cardanotestnet', null)
+houdini.set('celo', 'celo')
+houdini.set('coreum', null)
+houdini.set('cosmoshub', null)
+houdini.set('dash', 'dash')
+houdini.set('digibyte', null)
+houdini.set('dogecoin', 'doge')
+houdini.set('eboost', null)
+houdini.set('ecash', 'eCash')
+houdini.set('eos', null)
+houdini.set('ethDev', null)
+houdini.set('ethereum', 'ethereum')
+houdini.set('ethereumclassic', null)
+houdini.set('ethereumpow', null)
+houdini.set('fantom', 'fantom')
+houdini.set('feathercoin', null)
+houdini.set('filecoin', null)
+houdini.set('filecoinfevm', null)
+houdini.set('filecoinfevmcalibration', null)
+houdini.set('fio', null)
+houdini.set('groestlcoin', null)
+houdini.set('hedera', null)
+houdini.set('holesky', null)
+houdini.set('hyperevm', 'hyperevm')
+houdini.set('liberland', null)
+houdini.set('liberlandtestnet', null)
+houdini.set('litecoin', 'litecoin')
+houdini.set('mayachain', null)
+houdini.set('monad', null)
+houdini.set('monero', 'monero')
+houdini.set('nym', null)
+houdini.set('opbnb', 'opbnb')
+houdini.set('optimism', 'optimism')
+houdini.set('osmosis', null)
+houdini.set('piratechain', null)
+houdini.set('pivx', 'pivx')
+houdini.set('polkadot', 'polkadot')
+houdini.set('polygon', 'polygon')
+houdini.set('pulsechain', 'pulsechain')
+houdini.set('qtum', null)
+houdini.set('ravencoin', null)
+houdini.set('ripple', null)
+houdini.set('rsk', 'rootstock')
+houdini.set('sepolia', null)
+houdini.set('smartcash', null)
+houdini.set('solana', 'solana')
+houdini.set('sonic', 'sonic')
+houdini.set('stellar', null)
+houdini.set('sui', 'sui')
+houdini.set('suitestnet', null)
+houdini.set('telos', 'telos')
+houdini.set('tezos', null)
+houdini.set('thorchainrune', null)
+houdini.set('thorchainrunestagenet', null)
+houdini.set('ton', null)
+houdini.set('tron', 'tron')
+houdini.set('ufo', null)
+houdini.set('vertcoin', null)
+houdini.set('wax', null)
+houdini.set('zano', null)
+houdini.set('zcash', 'Zcash')
+houdini.set('zcoin', null)
+houdini.set('zksync', 'zksync-era')