{"id":23518,"library":"dbs3-client","title":"DBS3 Client","description":"Client library for the DBS3 (Data Bookkeeping Service) API, used in CMS (Compact Muon Solenoid) data management. Version 4.0.19 interacts with DBS3 server instances to query dataset, file, and block metadata. Release cadence is irregular.","status":"active","version":"4.0.19","language":"python","source_language":"en","source_url":"https://github.com/dmwm/DBSClient","tags":["CMS","data-bookkeeping","DBS","physics"],"install":[{"cmd":"pip install dbs3-client","lang":"bash","label":"Default install"}],"dependencies":[{"reason":"HTTP client for API calls","package":"requests","optional":false}],"imports":[{"note":"Class name is case-sensitive: DbsApi","wrong":"from dbs.apis.dbsClient import dbsApi","symbol":"DbsApi","correct":"from dbs.apis.dbsClient import DbsApi"}],"quickstart":{"code":"from dbs.apis.dbsClient import DbsApi\napi = DbsApi(url='https://cmsweb.cern.ch/dbs/prod/global/DBSReader')\ndatasets = api.listDatasets(dataset='/Muon/Run2016B-23Sep2016-v1/MINIAOD')\nprint(datasets)","lang":"python","description":"Creates a DbsApi instance and fetches datasets matching a pattern."},"warnings":[{"fix":"Transition to dbs-client and update imports to dbs.apis.dbsClient as this remains the same.","message":"The package dbs3-client is deprecated in favor of dbs-client (merged repo). New versions may break imports.","severity":"deprecated","affected_versions":">=4.0.0"},{"fix":"Use full URL with '/dbs/prod/global/DBSReader' as in quickstart.","message":"API URL must include trailing slash or specific path; missing path causes HTTP 400.","severity":"breaking","affected_versions":"All"},{"fix":"Check if the returned list is empty before accessing elements.","message":"Many methods return lists of dictionaries; assume empty list on error (no exception raised for empty results).","severity":"gotcha","affected_versions":"All"}],"env_vars":null,"last_verified":"2026-05-01T00:00:00.000Z","next_check":"2026-07-30T00:00:00.000Z","problems":[{"fix":"Run 'pip install dbs3-client' or 'pip install dbs-client' and ensure the environment is correct.","cause":"Package not installed or installed as a different name (dbs-client vs dbs3-client).","error":"ImportError: No module named dbs.apis.dbsClient"},{"fix":"Verify URL, authentication, and method signature. Use 'api.listDatasets(dataset=...)' with correct key and value.","cause":"Wrong URL or authentication; also some API methods require specific parameters.","error":"'DbsApi' object has no attribute 'listDatasets'"}],"ecosystem":"pypi","meta_description":null,"install_score":null,"install_tag":null,"quickstart_score":null,"quickstart_tag":null}