diff --git a/package.json b/package.json
index d1075b233..7b2502bf9 100644
--- a/package.json
+++ b/package.json
@@ -19,7 +19,7 @@
     "test": "vitest run",
     "test:watch": "vitest",
     "test:edge": "deno test --allow-read --allow-env=DEMO_CODE_PEPPER,EXA_API_KEY,SUPABASE_URL,SUPABASE_SERVICE_ROLE_KEY,SPARRING_INTEGRITY_SECRET,OPENROUTER_API_KEY --allow-net=127.0.0.1 supabase/functions/",
-    "test:db": "supabase test db",
+    "test:db": "supabase test db && bash scripts/test-daily-quota.sh",
     "test:e2e": "playwright test --project=desktop-chromium --project=mobile-chromium",
     "test:e2e:webkit": "playwright test --project=webkit",
     "test:e2e:staging": "playwright test --project=staging",
diff --git a/scripts/test-daily-quota.sh b/scripts/test-daily-quota.sh
new file mode 100644
index 000000000..224dc13cc
--- /dev/null
+++ b/scripts/test-daily-quota.sh
@@ -0,0 +1,153 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+database_url="${SUPABASE_DB_URL:-postgresql://postgres:postgres@127.0.0.1:54322/postgres}"
+database_password="${SUPABASE_DB_PASSWORD:-postgres}"
+test_user_id="66666666-6666-4666-8666-666666666666"
+result_dir="$(mktemp -d)"
+first_pid=""
+second_pid=""
+
+cleanup() {
+  touch "$result_dir/release-first"
+  if [ -n "$first_pid" ]; then
+    wait "$first_pid" 2>/dev/null || true
+  fi
+  if [ -n "$second_pid" ]; then
+    wait "$second_pid" 2>/dev/null || true
+  fi
+  PGPASSWORD="$database_password" psql "$database_url" -qX --set ON_ERROR_STOP=1 \
+    --command "DELETE FROM auth.users WHERE id = '$test_user_id'" >/dev/null
+  rm -rf "$result_dir"
+}
+trap cleanup EXIT
+
+(
+  cd "$repo_root"
+  PGPASSWORD="$database_password" psql "$database_url" -qX --set ON_ERROR_STOP=1 <<'SQL'
+BEGIN;
+INSERT INTO auth.users (id)
+VALUES ('77777777-7777-4777-8777-777777777777');
+DROP FUNCTION public.consume_daily_quota(uuid, integer, text);
+CREATE FUNCTION public.consume_daily_quota(uuid, integer)
+RETURNS TABLE (allowed boolean, current_count integer)
+LANGUAGE sql
+AS $$ SELECT false, 0 $$;
+ALTER TABLE public.daily_usage_counters DROP CONSTRAINT daily_usage_counters_pkey;
+ALTER TABLE public.daily_usage_counters DROP COLUMN quota_key;
+ALTER TABLE public.daily_usage_counters
+  ADD CONSTRAINT daily_usage_counters_pkey PRIMARY KEY (user_id, usage_date);
+INSERT INTO public.daily_usage_counters (user_id, usage_date, request_count)
+VALUES ('77777777-7777-4777-8777-777777777777', CURRENT_DATE - 1, 7);
+\i supabase/migrations/20260920125555_scope_daily_usage_counters.sql
+DO $$
+BEGIN
+  IF NOT EXISTS (
+    SELECT 1
+    FROM public.daily_usage_counters
+    WHERE user_id = '77777777-7777-4777-8777-777777777777'
+      AND usage_date = CURRENT_DATE - 1
+      AND quota_key = 'ai'
+      AND request_count = 7
+  ) THEN
+    RAISE EXCEPTION 'legacy daily usage row was not preserved under the ai quota';
+  END IF;
+END;
+$$;
+ROLLBACK;
+SQL
+)
+echo "Legacy quota row migration: count 7 preserved under ai"
+
+PGPASSWORD="$database_password" psql "$database_url" -qX --set ON_ERROR_STOP=1 \
+  --command "DELETE FROM auth.users WHERE id = '$test_user_id'; INSERT INTO auth.users (id) VALUES ('$test_user_id')" \
+  >/dev/null
+
+reserve_first() {
+  PGPASSWORD="$database_password" psql "$database_url" -qAtX --set ON_ERROR_STOP=1 <<SQL
+BEGIN;
+SET LOCAL ROLE service_role;
+SELECT set_config('request.jwt.claim.role', 'service_role', true);
+SELECT allowed, current_count
+FROM public.consume_daily_quota('$test_user_id', 1, 'concurrent');
+\! touch "$result_dir/first-holds-lock"
+\! while [ ! -e "$result_dir/release-first" ]; do sleep 0.05; done
+COMMIT;
+SQL
+}
+
+reserve_second() {
+  PGPASSWORD="$database_password" psql "$database_url" -qAtX --set ON_ERROR_STOP=1 <<SQL
+BEGIN;
+SET LOCAL ROLE service_role;
+SELECT set_config('request.jwt.claim.role', 'service_role', true);
+SELECT allowed, current_count
+FROM public.consume_daily_quota('$test_user_id', 1, 'concurrent') /* daily_quota_concurrency_second */;
+COMMIT;
+SQL
+}
+
+reserve_first >"$result_dir/first" &
+first_pid=$!
+
+for _ in {1..100}; do
+  if [ -e "$result_dir/first-holds-lock" ]; then
+    break
+  fi
+  if ! kill -0 "$first_pid" 2>/dev/null; then
+    wait "$first_pid"
+  fi
+  sleep 0.05
+done
+if [ ! -e "$result_dir/first-holds-lock" ]; then
+  echo "first quota reservation did not acquire its row lock"
+  exit 1
+fi
+
+reserve_second >"$result_dir/second" &
+second_pid=$!
+
+second_is_waiting=false
+for _ in {1..100}; do
+  if [ "$(PGPASSWORD="$database_password" psql "$database_url" -qAtX --set ON_ERROR_STOP=1 --command \
+    "SELECT EXISTS (SELECT 1 FROM pg_stat_activity WHERE pid <> pg_backend_pid() AND wait_event_type = 'Lock' AND query LIKE '%daily_quota_concurrency_second%')")" = "t" ]; then
+    second_is_waiting=true
+    break
+  fi
+  if ! kill -0 "$second_pid" 2>/dev/null; then
+    break
+  fi
+  sleep 0.05
+done
+if [ "$second_is_waiting" != true ]; then
+  echo "second quota reservation did not wait on the first row lock"
+  exit 1
+fi
+
+touch "$result_dir/release-first"
+
+first_result=0
+second_result=0
+wait "$first_pid" || first_result=$?
+wait "$second_pid" || second_result=$?
+if [ "$first_result" -ne 0 ] || [ "$second_result" -ne 0 ]; then
+  exit 1
+fi
+
+actual_results="$(grep -hE '^[tf]\|[0-9]+$' "$result_dir/first" "$result_dir/second" | sort)"
+expected_results=$'f|1\nt|1'
+if [ "$actual_results" != "$expected_results" ]; then
+  echo "unexpected concurrent quota results:"
+  echo "$actual_results"
+  exit 1
+fi
+
+stored_count="$(PGPASSWORD="$database_password" psql "$database_url" -qAtX --set ON_ERROR_STOP=1 --command \
+  "SELECT request_count FROM public.daily_usage_counters WHERE user_id = '$test_user_id' AND usage_date = CURRENT_DATE AND quota_key = 'concurrent'")"
+if [ "$stored_count" != "1" ]; then
+  echo "expected one stored concurrent reservation, got: $stored_count"
+  exit 1
+fi
+
+echo "Concurrent quota reservations: 1 allowed, 1 rejected, stored count 1"
diff --git a/supabase/functions/import-source/index.ts b/supabase/functions/import-source/index.ts
index e6f5977b0..801a2e38f 100644
--- a/supabase/functions/import-source/index.ts
+++ b/supabase/functions/import-source/index.ts
@@ -49,6 +49,7 @@ async function consumeDailyImportQuota(userId: string): Promise<{ allowed: boole
   const { data, error } = await supabase.rpc("consume_daily_quota", {
     p_user_id: userId,
     p_limit: DAILY_IMPORT_LIMIT,
+    p_quota_key: "import_source",
   });
   if (error) throw error;
   const row = Array.isArray(data) ? data[0] : data;
@@ -238,7 +239,7 @@ function normalizeText(text: string) {
     .slice(0, MAX_CONTENT_CHARS);
 }
 
-Deno.serve(async (req) => {
+export async function handleRequest(req: Request): Promise<Response> {
   const corsHeaders = getCorsHeaders(req.headers.get("origin"));
 
   if (req.method === "OPTIONS") {
@@ -331,4 +332,8 @@ Deno.serve(async (req) => {
     await logImport(user.id, "error", "exception", Date.now() - startedAt);
     return jsonResponse({ error: message }, 400, corsHeaders);
   }
-});
+}
+
+if (import.meta.main) {
+  Deno.serve(handleRequest);
+}
diff --git a/supabase/functions/import-source/index_test.ts b/supabase/functions/import-source/index_test.ts
new file mode 100644
index 000000000..099fe1a56
--- /dev/null
+++ b/supabase/functions/import-source/index_test.ts
@@ -0,0 +1,70 @@
+const environment = {
+  SUPABASE_URL: "https://supabase.test",
+  SUPABASE_SERVICE_ROLE_KEY: "test-service-role-key",
+};
+
+for (const [key, value] of Object.entries(environment)) {
+  Deno.env.set(key, value);
+}
+
+const { handleRequest } = await import("./index.ts");
+
+function jsonResponse(body: unknown, status = 200): Response {
+  return Response.json(body, { status });
+}
+
+Deno.test("import-source reserves only import_source quota", async () => {
+  const originalFetch = globalThis.fetch;
+  let quotaRequest: Record<string, unknown> | undefined;
+
+  globalThis.fetch =
+    (async (input: Request | URL | string, init?: RequestInit) => {
+      const url = new URL(input instanceof Request ? input.url : String(input));
+
+      if (url.origin !== "https://supabase.test") {
+        throw new Error(`Unexpected request: ${url}`);
+      }
+      if (url.pathname === "/auth/v1/user") {
+        return jsonResponse({ id: "user-1", aud: "authenticated" });
+      }
+      if (url.pathname.includes("/rest/v1/user_roles")) {
+        return jsonResponse({ role: "user" });
+      }
+      if (url.pathname.includes("/rest/v1/rpc/consume_daily_quota")) {
+        quotaRequest = JSON.parse(String(init?.body)) as Record<
+          string,
+          unknown
+        >;
+        return jsonResponse([{ allowed: false, current_count: 50 }]);
+      }
+      throw new Error(`Unexpected Supabase request: ${url}`);
+    }) as typeof fetch;
+
+  try {
+    const response = await handleRequest(
+      new Request("http://127.0.0.1/functions/v1/import-source", {
+        method: "POST",
+        headers: {
+          Authorization: "Bearer test-user-token",
+          "Content-Type": "application/json",
+        },
+        body: JSON.stringify({ url: "https://example.com/article" }),
+      }),
+    );
+
+    if (response.status !== 429) {
+      throw new Error(
+        `import-source returned ${response.status}: ${await response.text()}`,
+      );
+    }
+    if (quotaRequest?.p_quota_key !== "import_source") {
+      throw new Error(
+        `import-source reserved the wrong quota: ${
+          JSON.stringify(quotaRequest)
+        }`,
+      );
+    }
+  } finally {
+    globalThis.fetch = originalFetch;
+  }
+});
diff --git a/supabase/migrations/20260920125555_scope_daily_usage_counters.sql b/supabase/migrations/20260920125555_scope_daily_usage_counters.sql
new file mode 100644
index 000000000..602a4c460
--- /dev/null
+++ b/supabase/migrations/20260920125555_scope_daily_usage_counters.sql
@@ -0,0 +1,59 @@
+-- Keep independently configured daily quotas in separate atomic counters.
+ALTER TABLE public.daily_usage_counters
+  ADD COLUMN quota_key text NOT NULL DEFAULT 'ai';
+
+ALTER TABLE public.daily_usage_counters
+  DROP CONSTRAINT daily_usage_counters_pkey;
+
+ALTER TABLE public.daily_usage_counters
+  ADD CONSTRAINT daily_usage_counters_pkey
+  PRIMARY KEY (user_id, usage_date, quota_key);
+
+-- The new defaulted parameter changes the PostgreSQL function signature, so
+-- remove the old overload before creating its replacement.
+DROP FUNCTION public.consume_daily_quota(uuid, integer);
+
+CREATE FUNCTION public.consume_daily_quota(
+  p_user_id uuid,
+  p_limit integer,
+  p_quota_key text DEFAULT 'ai'
+)
+RETURNS TABLE (allowed boolean, current_count integer)
+LANGUAGE plpgsql
+SECURITY DEFINER
+SET search_path = public
+AS $$
+DECLARE
+  v_quota_key text := nullif(trim(p_quota_key), '');
+  v_current_count integer;
+BEGIN
+  IF auth.role() <> 'service_role' OR p_user_id IS NULL OR p_limit < 1 OR v_quota_key IS NULL THEN
+    RAISE EXCEPTION 'quota reservation is restricted to trusted server code';
+  END IF;
+
+  INSERT INTO public.daily_usage_counters (user_id, usage_date, quota_key, request_count)
+  VALUES (p_user_id, CURRENT_DATE, v_quota_key, 1)
+  ON CONFLICT (user_id, usage_date, quota_key) DO UPDATE
+    SET request_count = public.daily_usage_counters.request_count + 1
+    WHERE public.daily_usage_counters.request_count < p_limit
+  RETURNING request_count INTO v_current_count;
+
+  IF FOUND THEN
+    RETURN QUERY SELECT true, v_current_count;
+    RETURN;
+  END IF;
+
+  SELECT request_count INTO v_current_count
+  FROM public.daily_usage_counters
+  WHERE user_id = p_user_id
+    AND usage_date = CURRENT_DATE
+    AND quota_key = v_quota_key;
+
+  RETURN QUERY SELECT false, COALESCE(v_current_count, 0);
+END;
+$$;
+
+REVOKE ALL ON FUNCTION public.consume_daily_quota(uuid, integer, text)
+  FROM PUBLIC, anon, authenticated;
+GRANT EXECUTE ON FUNCTION public.consume_daily_quota(uuid, integer, text)
+  TO service_role;
diff --git a/supabase/tests/daily_usage_quota_test.sql b/supabase/tests/daily_usage_quota_test.sql
new file mode 100644
index 000000000..7219d4070
--- /dev/null
+++ b/supabase/tests/daily_usage_quota_test.sql
@@ -0,0 +1,116 @@
+BEGIN;
+SELECT plan(15);
+
+INSERT INTO auth.users (id)
+VALUES
+  ('44444444-4444-4444-8444-444444444444'),
+  ('55555555-5555-4555-8555-555555555555');
+
+SELECT has_column(
+  'public',
+  'daily_usage_counters',
+  'quota_key',
+  'daily usage counters identify the quota being consumed'
+);
+SELECT col_not_null(
+  'public',
+  'daily_usage_counters',
+  'quota_key',
+  'quota keys cannot be null'
+);
+SELECT col_default_is(
+  'public',
+  'daily_usage_counters',
+  'quota_key',
+  'ai',
+  'existing and omitted quota keys default to ai'
+);
+SELECT results_eq(
+  $$SELECT pg_get_constraintdef(oid)
+    FROM pg_constraint
+    WHERE conrelid = 'public.daily_usage_counters'::regclass
+      AND contype = 'p'$$,
+  ARRAY['PRIMARY KEY (user_id, usage_date, quota_key)'],
+  'the primary key scopes counters by quota key'
+);
+SELECT results_eq(
+  $$SELECT count(*)::bigint
+    FROM pg_proc
+    WHERE pronamespace = 'public'::regnamespace
+      AND proname = 'consume_daily_quota'$$,
+  ARRAY[1::bigint],
+  'the migration leaves one consume_daily_quota overload'
+);
+SELECT ok(
+  NOT has_function_privilege('anon', 'public.consume_daily_quota(uuid, integer, text)', 'EXECUTE'),
+  'anonymous callers cannot reserve quota'
+);
+SELECT ok(
+  NOT has_function_privilege('authenticated', 'public.consume_daily_quota(uuid, integer, text)', 'EXECUTE'),
+  'authenticated callers cannot reserve quota'
+);
+SELECT ok(
+  has_function_privilege('service_role', 'public.consume_daily_quota(uuid, integer, text)', 'EXECUTE'),
+  'service role can reserve quota'
+);
+
+SET LOCAL ROLE authenticated;
+SELECT set_config('request.jwt.claim.role', 'authenticated', true);
+SELECT throws_ok(
+  $$SELECT * FROM public.consume_daily_quota('44444444-4444-4444-8444-444444444444', 3)$$,
+  '42501',
+  NULL,
+  'unauthorized callers still cannot execute the quota RPC'
+);
+
+RESET ROLE;
+SET LOCAL ROLE service_role;
+SELECT set_config('request.jwt.claim.role', 'service_role', true);
+
+SELECT results_eq(
+  $$SELECT allowed, current_count
+    FROM public.consume_daily_quota('44444444-4444-4444-8444-444444444444', 3)$$,
+  $$VALUES (true, 1)$$,
+  'calls that omit the quota key reserve ai quota'
+);
+SELECT results_eq(
+  $$SELECT allowed, current_count
+    FROM public.consume_daily_quota('44444444-4444-4444-8444-444444444444', 1, 'import_source')$$,
+  $$VALUES (true, 1)$$,
+  'import reservations increment the import_source counter'
+);
+SELECT results_eq(
+  $$SELECT allowed, current_count
+    FROM public.consume_daily_quota('44444444-4444-4444-8444-444444444444', 1, 'import_source')$$,
+  $$VALUES (false, 1)$$,
+  'the import_source counter enforces its own limit'
+);
+SELECT results_eq(
+  $$SELECT allowed, current_count
+    FROM public.consume_daily_quota('44444444-4444-4444-8444-444444444444', 3)$$,
+  $$VALUES (true, 2)$$,
+  'exhausting import quota does not exhaust ai quota'
+);
+SELECT results_eq(
+  $$SELECT quota_key, request_count
+    FROM public.daily_usage_counters
+    WHERE user_id = '44444444-4444-4444-8444-444444444444'
+    ORDER BY quota_key$$,
+  $$VALUES ('ai'::text, 2), ('import_source'::text, 1)$$,
+  'ai and import reservations update only their own counters'
+);
+
+RESET ROLE;
+INSERT INTO public.daily_usage_counters (user_id, usage_date, request_count)
+VALUES ('55555555-5555-4555-8555-555555555555', CURRENT_DATE - 1, 7);
+SELECT results_eq(
+  $$SELECT quota_key, request_count
+    FROM public.daily_usage_counters
+    WHERE user_id = '55555555-5555-4555-8555-555555555555'
+      AND usage_date = CURRENT_DATE - 1$$,
+  $$VALUES ('ai'::text, 7)$$,
+  'rows without an explicit quota key retain their count under ai'
+);
+
+SELECT * FROM finish();
+ROLLBACK;