{"success":true,"message":"AT Protocol Firehose Filter Server API","data":{"endpoints":["GET /api/status - Get server status","GET /api/filters - Get current filters","POST /api/filters/create - Create new filter subscription","GET /api/subscriptions/{filterKey} - Get subscription details","GET /api/stats - Get subscription statistics"],"filters":{"keyword":"Filter by keywords in text content (comma-separated, e.g., 'hello,world,test')","pathPrefix":"Filter by operation path prefix (e.g., 'app.bsky.feed.post')","repository":"Filter by repository DID (e.g., 'did:plc:abc123')"},"requirements":["Keyword filter is required for all subscriptions","Each filter field (repository, pathPrefix, keyword) must contain at least 3 letters","Keywords are comma-separated and each must have at least 3 letters"]}}