From 3288f27e37cb60095c9ff39f1b63218d5fd1b5f8 Mon Sep 17 00:00:00 2001
From: Femi John <your-email@example.com>
Date: Thu, 25 Jun 2026 14:09:30 +0100
Subject: [PATCH 1/2] feat: add GET /spreads/:asset route to calculate bid-ask
 spreads for given assets

---
 src/routes/spreads.ts | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 src/routes/spreads.ts

diff --git a/src/routes/spreads.ts b/src/routes/spreads.ts
new file mode 100644
index 0000000..b1c92d7
--- /dev/null
+++ b/src/routes/spreads.ts
@@ -0,0 +1,32 @@
+import type { FastifyInstance } from 'fastify';
+import { pgPool } from '../db';
+
+/**
+ * GET /spreads/:asset - Return current bid, ask, and spread (bps) for the given asset.
+ * The bid is taken as the highest price among price points where the asset appears.
+ * The ask is the lowest price among those points.
+ * Spread basis points = ((ask - bid) / ask) * 10_000.
+ */
+export async function registerSpreadsRoutes(app: FastifyInstance) {
+  app.get('/spreads/:asset', async (req, reply) => {
+    const { asset } = req.params as { asset: string };
+    if (!asset) {
+      return reply.status(400).send({ error: 'Asset parameter is required' });
+    }
+
+    const result = await pgPool.query(
+      `SELECT MAX(price::numeric) AS bid, MIN(price::numeric) AS ask
+       FROM price_points
+       WHERE assetA = $1 OR assetB = $1`,
+      [asset]
+    );
+    const row = result.rows[0];
+    const bid = row.bid !== null ? parseFloat(row.bid) : null;
+    const ask = row.ask !== null ? parseFloat(row.ask) : null;
+    let spreadBps: number | null = null;
+    if (bid !== null && ask !== null && ask !== 0) {
+      spreadBps = ((ask - bid) / ask) * 10_000;
+    }
+    return { asset, bid, ask, spreadBps };
+  });
+}

From c5dc120f4ea8df3e0eaa831a1deae49c6be34d01 Mon Sep 17 00:00:00 2001
From: Femi John <your-email@example.com>
Date: Sat, 27 Jun 2026 19:36:50 +0100
Subject: [PATCH 2/2] fix: correct bid/ask logic and column identifiers in
 spread calculation query

---
 src/routes/spreads.ts | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/routes/spreads.ts b/src/routes/spreads.ts
index b1c92d7..f548e57 100644
--- a/src/routes/spreads.ts
+++ b/src/routes/spreads.ts
@@ -3,9 +3,9 @@ import { pgPool } from '../db';
 
 /**
  * GET /spreads/:asset - Return current bid, ask, and spread (bps) for the given asset.
- * The bid is taken as the highest price among price points where the asset appears.
- * The ask is the lowest price among those points.
- * Spread basis points = ((ask - bid) / ask) * 10_000.
+ * The bid is the minimum price among price points where the asset appears.
+ * The ask is the maximum price among those points.
+ * Spread basis points = ((ask - bid) / ask) * 10_000 (non‑negative).
  */
 export async function registerSpreadsRoutes(app: FastifyInstance) {
   app.get('/spreads/:asset', async (req, reply) => {
@@ -15,9 +15,9 @@ export async function registerSpreadsRoutes(app: FastifyInstance) {
     }
 
     const result = await pgPool.query(
-      `SELECT MAX(price::numeric) AS bid, MIN(price::numeric) AS ask
-       FROM price_points
-       WHERE assetA = $1 OR assetB = $1`,
+      `SELECT MIN(price::numeric) AS bid, MAX(price::numeric) AS ask
+        FROM price_points
+        WHERE "asset_a" = $1 OR "asset_b" = $1`,
       [asset]
     );
     const row = result.rows[0];