fix(swap): quote-time refund-risk boundaries — fee/slippage gate + route minimums

projects/keepkey-vault/__tests__/swap-parsing.test.ts

@@ -163,6 +163,25 @@ describe('parseQuoteResponse', () => {
     expect(result.memo).toBe('=:ETH.ETH:0xdest123:245000/3/0:kk:0')
   })
 
+  test('THORChain recommended_min_amount_in converts 1e8 base units to decimal minAmountIn', () => {
+    // 27472 sats input got refunded on-chain ("Emit asset less than price
+    // limit") because nothing enforced THORNode's floor. 50000 base units of
+    // the sell asset = 0.0005 decimal — a unit slip here (comparing 1e8
+    // against a human amount) would make the guard block every swap.
+    const fixture = JSON.parse(JSON.stringify(FIXTURE_BASE_TO_ETH_QUOTE))
+    fixture.data.data[0].quote.raw.recommended_min_amount_in = '50000'
+    const result = parseQuoteResponse(fixture, baseParams)
+    expect(result.minAmountIn).toBe('0.0005')
+  })
+
+  test('recommended_min_amount_in ignored for non-THORChain swappers (unknown units)', () => {
+    const fixture = JSON.parse(JSON.stringify(FIXTURE_BASE_TO_ETH_QUOTE))
+    fixture.data.data[0].integration = 'relay'
+    fixture.data.data[0].quote.raw.recommended_min_amount_in = '50000'
+    const result = parseQuoteResponse(fixture, baseParams)
+    expect(result.minAmountIn).toBeUndefined()
+  })
+
   test('BASE → ETH: extracts router from raw', () => {
     const result = parseQuoteResponse(FIXTURE_BASE_TO_ETH_QUOTE, baseParams)
     expect(result.router).toBe('0x1b3e6daa08e7a2e29e2ff23b6c40abe79a15a17a')

projects/keepkey-vault/src/bun/swap-parsing.ts

@@ -332,7 +332,19 @@ function parseSingleQuote(
   // Minimum sell amount — solvers/protocols may refuse amounts below this floor
   // Check multiple field names across the response layers (Pioneer schema varies by swapper)
   const minAmountInRaw = quote.minAmountIn ?? best.minAmountIn ?? raw.min_amount_in ?? raw.minAmountIn
-  const minAmountIn: string | undefined = minAmountInRaw != null ? String(minAmountInRaw) : undefined
+  let minAmountIn: string | undefined = minAmountInRaw != null ? String(minAmountInRaw) : undefined
+  // THORChain-family routes publish recommended_min_amount_in — the floor
+  // below which fixed outbound fees dominate and the chain refunds the swap
+  // ("Emit asset less than price limit", minus another outbound fee). It is
+  // ALWAYS 1e8 base units of the sell asset regardless of chain; only trusted
+  // for THORChain routes — other swappers' units vary, so no generic fallback.
+  if (!minAmountIn && /thor|maya/i.test(`${integration} ${swapper ?? ''}`)) {
+    const rec = raw.recommended_min_amount_in ?? quote.recommended_min_amount_in ?? best.recommended_min_amount_in
+    const recNum = rec != null ? Number(rec) : NaN
+    if (Number.isFinite(recNum) && recNum > 0) {
+      minAmountIn = (recNum / 1e8).toFixed(8).replace(/\.?0+$/, '')
+    }
+  }
 
   // For NEAR Intents ERC-20 routes, Pioneer embeds the 1Click deposit address in
   // txParams.recipientAddress (same as quote.meta.depositAddress). This is the

projects/keepkey-vault/src/bun/swap.ts

@@ -349,6 +349,33 @@ export async function getSwapQuote(params: SwapQuoteParams): Promise<SwapQuote>
     : (result.integration || 'unknown')
   swapLog(`${TAG} Quote: ${result.expectedOutput} (${route}), memo=${result.memo || 'NONE'}, router=${result.router || 'NONE'}, expiry=${result.expiry}`)
 
+  // ── Refund-risk boundaries (every route) ──────────────────────────────
+  // A protocol refunds when the emitted amount lands below the memo's price
+  // limit — and the refund itself burns another outbound fee (observed:
+  // $17.76 BTC→ETH came back as $14.52). Two unit-safe gates at quote time:
+  //
+  // 1. Fees eating the slippage allowance. totalBps is basis points across
+  //    every integration. If quoted fees >= the slippage tolerance, the swap
+  //    only completes when the price moves in our favor during confirmation —
+  //    on small amounts the fixed outbound fee guarantees a refund instead.
+  const feeBps = Number(result.fees?.totalBps) || 0
+  if (feeBps >= slippageBps) {
+    throw new Error(
+      `Swap amount too low: quoted fees (${(feeBps / 100).toFixed(2)}%) meet or exceed the ` +
+      `slippage allowance (${(slippageBps / 100).toFixed(2)}%), so the protocol would refund ` +
+      `this swap on-chain — minus another network fee. Increase the amount.`
+    )
+  }
+  // 2. Route-declared minimum sell amount — enforced for ALL integrations
+  //    (previously only the NEAR Intents block checked it, so THORChain
+  //    routes sailed past their recommended_min_amount_in).
+  if (result.minAmountIn && parseFloat(params.amount) < parseFloat(result.minAmountIn)) {
+    throw new Error(
+      `Amount below this route's minimum (~${result.minAmountIn}). ` +
+      `Smaller deposits are systematically refunded after fees.`
+    )
+  }
+
   // NEAR Intents: solver-network minimum amount check for ALL source chains.
   // Solvers must front the destination-chain gas and wait for source confirmations;
   // amounts below their profitability floor are systematically refunded.