diff --git a/lib/airdrop/sql.test.ts b/lib/airdrop/sql.test.ts
new file mode 100644
index 0000000..4a61e5a
--- /dev/null
+++ b/lib/airdrop/sql.test.ts
@@ -0,0 +1,270 @@
+// @vitest-environment node
+import { describe, expect, it, beforeAll, afterAll } from "vitest";
+import { PGlite } from "@electric-sql/pglite";
+import { weightedSpendQuery } from "./sql";
+import type { AirdropConfig } from "./config";
+
+let db: PGlite;
+
+function buildConfig(overrides: Partial<AirdropConfig> = {}): AirdropConfig {
+  return {
+    CAMPAIGN_START: new Date("2026-07-01T00:00:00Z"),
+    CAMPAIGN_END: new Date("2026-10-01T00:00:00Z"),
+    POOL_AMOUNT: 200_000,
+    MILESTONES: {
+      BRONZE: { mcap: 100_000, pct: 10 },
+      SILVER: { mcap: 1_000_000, pct: 30 },
+      GOLD: { mcap: 5_000_000, pct: 50 },
+      DIAMOND: { mcap: 10_000_000, pct: 100 },
+    },
+    LOCKER_TX: null,
+    POINTS: { BUY_PER_PLOT: 1, REFERRAL_PCT: 20, WRITE_FLAT: 50, RATE_FLAT: 5, RATE_DAILY_CAP: 10 },
+    STREAK_BOOSTS: {},
+    STREAK_MIN_GAP_MINUTES: 30,
+    MIN_REFERRAL_THRESHOLD: 50,
+    REFERRAL_MULTIPLIER_PER_REF: 0.2,
+    REFERRAL_MULTIPLIER_CAP: 3.0,
+    SIGNATURE_FRESHNESS_MIN: 10,
+    SIWE_DOMAIN: "plotlink.xyz",
+    SIWE_URI: "https://plotlink.xyz/airdrop",
+    SIWE_STATEMENT: "PlotLink Buy-Back Sprint activation",
+    SIWE_CHAIN_ID: 8453,
+    PLOTLINK_X_HANDLE: "plotlinkxyz",
+    PLOTLINK_FC_FID: 0,
+    CLAIM_WINDOW_DAYS: 30,
+    ...overrides,
+  };
+}
+
+beforeAll(async () => {
+  db = new PGlite();
+  await db.exec(`
+    CREATE TABLE pl_activations (
+      address TEXT PRIMARY KEY,
+      fid BIGINT,
+      activated_at TIMESTAMPTZ,
+      is_blacklisted BOOLEAN NOT NULL DEFAULT FALSE
+    );
+    CREATE TABLE pl_points (
+      id SERIAL PRIMARY KEY,
+      address TEXT NOT NULL,
+      action TEXT NOT NULL,
+      points NUMERIC NOT NULL,
+      created_at TIMESTAMPTZ DEFAULT NOW()
+    );
+    CREATE TABLE pl_referrals (
+      id SERIAL PRIMARY KEY,
+      referrer_address TEXT NOT NULL,
+      referred_address TEXT NOT NULL
+    );
+  `);
+});
+
+afterAll(async () => {
+  await db.close();
+});
+
+async function resetFixtures() {
+  await db.exec("DELETE FROM pl_referrals; DELETE FROM pl_points; DELETE FROM pl_activations;");
+}
+
+async function runQuery(config: AirdropConfig) {
+  const { sql, params } = weightedSpendQuery(config);
+  const result = await db.query(sql, params);
+  return result.rows as Array<{
+    address: string;
+    buy_volume: number;
+    qualified_refs: number;
+    has_fc_bonus: number;
+    multiplier: number;
+    weighted_spend: number;
+    community_total: number;
+  }>;
+}
+
+const IN_CAMPAIGN = "2026-08-01T00:00:00Z";
+const config = buildConfig();
+
+describe("weightedSpendQuery against PGlite", () => {
+  it("100 PLOT + 2 qualified refs + FC bonus → multiplier 1.6, weighted 160", async () => {
+    await resetFixtures();
+    await db.exec(`
+      INSERT INTO pl_activations (address, fid, activated_at) VALUES
+        ('alice', 123, '2026-07-01'),
+        ('ref1', NULL, '2026-07-01'),
+        ('ref2', NULL, '2026-07-01');
+      INSERT INTO pl_points (address, action, points, created_at) VALUES
+        ('alice', 'buy', 100, '${IN_CAMPAIGN}'),
+        ('ref1', 'buy', 60, '${IN_CAMPAIGN}'),
+        ('ref2', 'buy', 80, '${IN_CAMPAIGN}');
+      INSERT INTO pl_referrals (referrer_address, referred_address) VALUES
+        ('alice', 'ref1'),
+        ('alice', 'ref2');
+    `);
+
+    const rows = await runQuery(config);
+    const alice = rows.find(r => r.address === "alice")!;
+
+    expect(Number(alice.buy_volume)).toBe(100);
+    expect(Number(alice.qualified_refs)).toBe(2);
+    expect(Number(alice.has_fc_bonus)).toBe(1);
+    expect(Number(alice.multiplier)).toBeCloseTo(1.6);
+    expect(Number(alice.weighted_spend)).toBeCloseTo(160);
+  });
+
+  it("excludes blacklisted wallets from results", async () => {
+    await resetFixtures();
+    await db.exec(`
+      INSERT INTO pl_activations (address, activated_at, is_blacklisted) VALUES
+        ('good', '2026-07-01', FALSE),
+        ('bad', '2026-07-01', TRUE);
+      INSERT INTO pl_points (address, action, points, created_at) VALUES
+        ('good', 'buy', 100, '${IN_CAMPAIGN}'),
+        ('bad', 'buy', 100, '${IN_CAMPAIGN}');
+    `);
+
+    const rows = await runQuery(config);
+    expect(rows).toHaveLength(1);
+    expect(rows[0].address).toBe("good");
+  });
+
+  it("excludes non-activated wallets from results", async () => {
+    await resetFixtures();
+    await db.exec(`
+      INSERT INTO pl_activations (address, activated_at) VALUES
+        ('active', '2026-07-01'),
+        ('pending', NULL);
+      INSERT INTO pl_points (address, action, points, created_at) VALUES
+        ('active', 'buy', 100, '${IN_CAMPAIGN}'),
+        ('pending', 'buy', 100, '${IN_CAMPAIGN}');
+    `);
+
+    const rows = await runQuery(config);
+    expect(rows).toHaveLength(1);
+    expect(rows[0].address).toBe("active");
+  });
+
+  it("qualified_refs excludes non-activated referees", async () => {
+    await resetFixtures();
+    await db.exec(`
+      INSERT INTO pl_activations (address, activated_at) VALUES
+        ('alice', '2026-07-01'),
+        ('bob', '2026-07-01'),
+        ('charlie', NULL);
+      INSERT INTO pl_points (address, action, points, created_at) VALUES
+        ('alice', 'buy', 100, '${IN_CAMPAIGN}'),
+        ('bob', 'buy', 60, '${IN_CAMPAIGN}'),
+        ('charlie', 'buy', 60, '${IN_CAMPAIGN}');
+      INSERT INTO pl_referrals (referrer_address, referred_address) VALUES
+        ('alice', 'bob'),
+        ('alice', 'charlie');
+    `);
+
+    const rows = await runQuery(config);
+    const alice = rows.find(r => r.address === "alice")!;
+    expect(Number(alice.qualified_refs)).toBe(1);
+  });
+
+  it("qualified_refs excludes blacklisted referees", async () => {
+    await resetFixtures();
+    await db.exec(`
+      INSERT INTO pl_activations (address, activated_at, is_blacklisted) VALUES
+        ('alice', '2026-07-01', FALSE),
+        ('dave', '2026-07-01', TRUE);
+      INSERT INTO pl_points (address, action, points, created_at) VALUES
+        ('alice', 'buy', 100, '${IN_CAMPAIGN}'),
+        ('dave', 'buy', 60, '${IN_CAMPAIGN}');
+      INSERT INTO pl_referrals (referrer_address, referred_address) VALUES
+        ('alice', 'dave');
+    `);
+
+    const rows = await runQuery(config);
+    const alice = rows.find(r => r.address === "alice")!;
+    expect(Number(alice.qualified_refs)).toBe(0);
+  });
+
+  it("qualified_refs excludes under-threshold referees (49 < 50)", async () => {
+    await resetFixtures();
+    await db.exec(`
+      INSERT INTO pl_activations (address, activated_at) VALUES
+        ('alice', '2026-07-01'),
+        ('low', '2026-07-01'),
+        ('high', '2026-07-01');
+      INSERT INTO pl_points (address, action, points, created_at) VALUES
+        ('alice', 'buy', 100, '${IN_CAMPAIGN}'),
+        ('low', 'buy', 49, '${IN_CAMPAIGN}'),
+        ('high', 'buy', 50, '${IN_CAMPAIGN}');
+      INSERT INTO pl_referrals (referrer_address, referred_address) VALUES
+        ('alice', 'low'),
+        ('alice', 'high');
+    `);
+
+    const rows = await runQuery(config);
+    const alice = rows.find(r => r.address === "alice")!;
+    expect(Number(alice.qualified_refs)).toBe(1);
+  });
+
+  it("TEST vs PROD campaign windows produce different buy_volume", async () => {
+    await resetFixtures();
+    await db.exec(`
+      INSERT INTO pl_activations (address, activated_at) VALUES ('alice', '2026-06-01');
+      INSERT INTO pl_points (address, action, points, created_at) VALUES
+        ('alice', 'buy', 50, '2026-06-01T00:02:00Z'),
+        ('alice', 'buy', 75, '${IN_CAMPAIGN}');
+    `);
+
+    const testConfig = buildConfig({
+      CAMPAIGN_START: new Date("2026-06-01T00:00:00Z"),
+      CAMPAIGN_END: new Date("2026-06-01T00:05:00Z"),
+    });
+
+    const testRows = await runQuery(testConfig);
+    const prodRows = await runQuery(config);
+
+    expect(Number(testRows[0].buy_volume)).toBe(50);
+    expect(Number(prodRows[0].buy_volume)).toBe(75);
+  });
+
+  it("community_total sums all weighted_spend across rows", async () => {
+    await resetFixtures();
+    await db.exec(`
+      INSERT INTO pl_activations (address, activated_at) VALUES
+        ('a', '2026-07-01'),
+        ('b', '2026-07-01');
+      INSERT INTO pl_points (address, action, points, created_at) VALUES
+        ('a', 'buy', 100, '${IN_CAMPAIGN}'),
+        ('b', 'buy', 200, '${IN_CAMPAIGN}');
+    `);
+
+    const rows = await runQuery(config);
+    expect(Number(rows[0].community_total)).toBe(300);
+    expect(Number(rows[1].community_total)).toBe(300);
+  });
+
+  it("multiplier is capped at REFERRAL_MULTIPLIER_CAP", async () => {
+    await resetFixtures();
+    const refInserts = Array.from({ length: 20 }, (_, i) =>
+      `('ref${i}', '2026-07-01')`
+    ).join(",");
+    const buyInserts = Array.from({ length: 20 }, (_, i) =>
+      `('ref${i}', 'buy', 60, '${IN_CAMPAIGN}')`
+    ).join(",");
+    const relInserts = Array.from({ length: 20 }, (_, i) =>
+      `('whale', 'ref${i}')`
+    ).join(",");
+
+    await db.exec(`
+      INSERT INTO pl_activations (address, activated_at) VALUES
+        ('whale', '2026-07-01'), ${refInserts};
+      UPDATE pl_activations SET fid = 1 WHERE address = 'whale';
+      INSERT INTO pl_points (address, action, points, created_at) VALUES
+        ('whale', 'buy', 100, '${IN_CAMPAIGN}'), ${buyInserts};
+      INSERT INTO pl_referrals (referrer_address, referred_address) VALUES ${relInserts};
+    `);
+
+    const rows = await runQuery(config);
+    const whale = rows.find(r => r.address === "whale")!;
+    expect(Number(whale.multiplier)).toBe(3.0);
+    expect(Number(whale.weighted_spend)).toBeCloseTo(300);
+  });
+});
diff --git a/lib/airdrop/sql.ts b/lib/airdrop/sql.ts
new file mode 100644
index 0000000..a7eccb6
--- /dev/null
+++ b/lib/airdrop/sql.ts
@@ -0,0 +1,85 @@
+import type { AirdropConfig } from "./config";
+
+export interface WeightedSpendQuery {
+  sql: string;
+  params: (string | number)[];
+}
+
+export interface WeightedSpendRow {
+  address: string;
+  buy_volume: number;
+  qualified_refs: number;
+  has_fc_bonus: number;
+  multiplier: number;
+  weighted_spend: number;
+  community_total: number;
+}
+
+export function weightedSpendQuery(config: AirdropConfig): WeightedSpendQuery {
+  const params: (string | number)[] = [
+    config.CAMPAIGN_START.toISOString(),
+    config.CAMPAIGN_END.toISOString(),
+    config.MIN_REFERRAL_THRESHOLD,
+    config.REFERRAL_MULTIPLIER_PER_REF,
+    config.REFERRAL_MULTIPLIER_CAP,
+  ];
+
+  const sql = `
+WITH eligible AS (
+  SELECT
+    a.address,
+    CASE WHEN a.fid IS NOT NULL THEN 1 ELSE 0 END AS has_fc_bonus
+  FROM pl_activations a
+  WHERE a.activated_at IS NOT NULL
+    AND a.is_blacklisted = FALSE
+),
+buys AS (
+  SELECT p.address, COALESCE(SUM(p.points), 0) AS buy_volume
+  FROM pl_points p
+  WHERE p.action = 'buy'
+    AND p.created_at >= $1
+    AND p.created_at <= $2
+  GROUP BY p.address
+),
+eligible_buys AS (
+  SELECT e.address, e.has_fc_bonus, COALESCE(b.buy_volume, 0) AS buy_volume
+  FROM eligible e
+  JOIN buys b ON e.address = b.address
+),
+qualified_refs AS (
+  SELECT r.referrer_address AS address, COUNT(*) AS ref_count
+  FROM pl_referrals r
+  JOIN eligible_buys eb ON r.referred_address = eb.address
+  WHERE eb.buy_volume >= $3
+  GROUP BY r.referrer_address
+),
+weighted AS (
+  SELECT
+    eb.address,
+    eb.buy_volume,
+    COALESCE(qr.ref_count, 0) AS qualified_refs,
+    eb.has_fc_bonus,
+    LEAST(
+      1 + (COALESCE(qr.ref_count, 0) + eb.has_fc_bonus) * $4::NUMERIC,
+      $5::NUMERIC
+    ) AS multiplier,
+    eb.buy_volume * LEAST(
+      1 + (COALESCE(qr.ref_count, 0) + eb.has_fc_bonus) * $4::NUMERIC,
+      $5::NUMERIC
+    ) AS weighted_spend
+  FROM eligible_buys eb
+  LEFT JOIN qualified_refs qr ON eb.address = qr.address
+)
+SELECT
+  w.address,
+  w.buy_volume,
+  w.qualified_refs,
+  w.has_fc_bonus,
+  w.multiplier,
+  w.weighted_spend,
+  SUM(w.weighted_spend) OVER () AS community_total
+FROM weighted w
+`.trim();
+
+  return { sql, params };
+}
diff --git a/package-lock.json b/package-lock.json
index 3187aa6..de6a86e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "plotlink",
-  "version": "1.30.2",
+  "version": "1.30.5",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "plotlink",
-      "version": "1.30.2",
+      "version": "1.30.5",
       "workspaces": [
         "packages/*"
       ],
@@ -34,6 +34,7 @@
         "wagmi": "^2.19.5"
       },
       "devDependencies": {
+        "@electric-sql/pglite": "^0.4.6",
         "@playwright/test": "^1.58.2",
         "@tailwindcss/postcss": "^4",
         "@testing-library/jest-dom": "^6.9.1",
@@ -1700,6 +1701,13 @@
         "@noble/ciphers": "^1.0.0"
       }
     },
+    "node_modules/@electric-sql/pglite": {
+      "version": "0.4.6",
+      "resolved": "https://registry.npmjs.org/@electric-sql/pglite/-/pglite-0.4.6.tgz",
+      "integrity": "sha512-qmlmfN8UyKCee35qkV0r/MBp+Znl8FjBz7OpoglNvww3GJpw0/DLP0o1ZymvLNmcD5DTLOQdzKPtF8Hd3mdl1w==",
+      "dev": true,
+      "license": "Apache-2.0"
+    },
     "node_modules/@emnapi/core": {
       "version": "1.10.0",
       "resolved": "https://registry.npmjs.org/@emnapi/core/-/core-1.10.0.tgz",
diff --git a/package.json b/package.json
index d327702..4cb790f 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "plotlink",
-  "version": "1.30.4",
+  "version": "1.30.5",
   "private": true,
   "workspaces": [
     "packages/*"
@@ -38,6 +38,7 @@
     "wagmi": "^2.19.5"
   },
   "devDependencies": {
+    "@electric-sql/pglite": "^0.4.6",
     "@playwright/test": "^1.58.2",
     "@tailwindcss/postcss": "^4",
     "@testing-library/jest-dom": "^6.9.1",