1 files changed, 80 insertions, 0 deletions
diff --git a/apps/web/lib/api-auth.ts b/apps/web/lib/api-auth.ts
new file mode 100644
index 0000000..309fbe9
--- /dev/null
+++ b/apps/web/lib/api-auth.ts
@@ -0,0 +1,80 @@
+import { createSupabaseAdminClient } from "@/lib/supabase/admin"
+import { hashApiKey } from "@/lib/api-key"
+import { rateLimit } from "@/lib/rate-limit"
+
+interface AuthenticatedApiUser {
+  userIdentifier: string
+  tier: string
+}
+
+export async function authenticateApiRequest(
+  request: Request
+): Promise<
+  | { authenticated: true; user: AuthenticatedApiUser }
+  | { authenticated: false; status: number; error: string }
+> {
+  const authorizationHeader = request.headers.get("authorization")
+
+  if (!authorizationHeader?.startsWith("Bearer ")) {
+    return {
+      authenticated: false,
+      status: 401,
+      error: "Missing or invalid Authorization header",
+    }
+  }
+
+  const apiKey = authorizationHeader.slice(7)
+
+  if (!apiKey.startsWith("asn_")) {
+    return { authenticated: false, status: 401, error: "Invalid API key format" }
+  }
+
+  const keyHash = hashApiKey(apiKey)
+  const adminClient = createSupabaseAdminClient()
+
+  const { data: keyRow } = await adminClient
+    .from("api_keys")
+    .select("user_id")
+    .eq("key_hash", keyHash)
+    .is("revoked_at", null)
+    .single()
+
+  if (!keyRow) {
+    return { authenticated: false, status: 401, error: "Invalid or revoked API key" }
+  }
+
+  const { data: userProfile } = await adminClient
+    .from("user_profiles")
+    .select("tier")
+    .eq("id", keyRow.user_id)
+    .single()
+
+  if (!userProfile || userProfile.tier !== "developer") {
+    return {
+      authenticated: false,
+      status: 403,
+      error: "API access requires the developer plan",
+    }
+  }
+
+  const rateLimitResult = rateLimit(`api:${keyRow.user_id}`, 100, 60_000)
+
+  if (!rateLimitResult.success) {
+    return {
+      authenticated: false,
+      status: 429,
+      error: `Rate limit exceeded. ${rateLimitResult.remaining} requests remaining.`,
+    }
+  }
+
+  adminClient
+    .from("api_keys")
+    .update({ last_used_at: new Date().toISOString() })
+    .eq("key_hash", keyHash)
+    .then(() => {})
+
+  return {
+    authenticated: true,
+    user: { userIdentifier: keyRow.user_id, tier: userProfile.tier },
+  }
+}