{"record":{"id":"1b844207359c7427","repo":"browser-use/browser-use","slug":"func-name-missing-required-special-paramet","errorCode":null,"errorMessage":"{func.__name__}() missing required special parameter '{param.name}'","messagePattern":"(.+?)\\(\\) missing required special parameter '(.+?)'","errorType":"validation","errorClass":"ValueError","httpStatus":null,"severity":"error","filePath":"browser_use/tools/registry/service.py","lineNumber":225,"sourceCode":"\t\t\t\t\t# This is a special parameter\n\t\t\t\t\tif param.name in kwargs:\n\t\t\t\t\t\tvalue = kwargs[param.name]\n\t\t\t\t\t\t# Check if required special param is None\n\t\t\t\t\t\tif value is None and param.default == Parameter.empty:\n\t\t\t\t\t\t\tif param.name == 'browser_session':\n\t\t\t\t\t\t\t\traise ValueError(f'Action {func.__name__} requires browser_session but none provided.')\n\t\t\t\t\t\t\telif param.name == 'page_extraction_llm':\n\t\t\t\t\t\t\t\traise ValueError(f'Action {func.__name__} requires page_extraction_llm but none provided.')\n\t\t\t\t\t\t\telif param.name == 'file_system':\n\t\t\t\t\t\t\t\traise ValueError(f'Action {func.__name__} requires file_system but none provided.')\n\t\t\t\t\t\t\telif param.name == 'page':\n\t\t\t\t\t\t\t\traise ValueError(f'Action {func.__name__} requires page but none provided.')\n\t\t\t\t\t\t\telif param.name == 'available_file_paths':\n\t\t\t\t\t\t\t\traise ValueError(f'Action {func.__name__} requires available_file_paths but none provided.')\n\t\t\t\t\t\t\telif param.name == 'file_system':\n\t\t\t\t\t\t\t\traise ValueError(f'Action {func.__name__} requires file_system but none provided.')\n\t\t\t\t\t\t\telse:\n\t\t\t\t\t\t\t\traise ValueError(f\"{func.__name__}() missing required special parameter '{param.name}'\")\n\t\t\t\t\t\tcall_args.append(value)\n\t\t\t\t\telif param.default != Parameter.empty:\n\t\t\t\t\t\tcall_args.append(param.default)\n\t\t\t\t\telse:\n\t\t\t\t\t\t# Special param is required but not provided\n\t\t\t\t\t\tif param.name == 'browser_session':\n\t\t\t\t\t\t\traise ValueError(f'Action {func.__name__} requires browser_session but none provided.')\n\t\t\t\t\t\telif param.name == 'page_extraction_llm':\n\t\t\t\t\t\t\traise ValueError(f'Action {func.__name__} requires page_extraction_llm but none provided.')\n\t\t\t\t\t\telif param.name == 'file_system':\n\t\t\t\t\t\t\traise ValueError(f'Action {func.__name__} requires file_system but none provided.')\n\t\t\t\t\t\telif param.name == 'page':\n\t\t\t\t\t\t\traise ValueError(f'Action {func.__name__} requires page but none provided.')\n\t\t\t\t\t\telif param.name == 'available_file_paths':\n\t\t\t\t\t\t\traise ValueError(f'Action {func.__name__} requires available_file_paths but none provided.')\n\t\t\t\t\t\telif param.name == 'file_system':\n\t\t\t\t\t\t\traise ValueError(f'Action {func.__name__} requires file_system but none provided.')\n\t\t\t\t\t\telse:","sourceCodeStart":207,"sourceCodeEnd":243,"githubUrl":"https://github.com/browser-use/browser-use/blob/6c73fced2f6d45a11d88622fe56365a5fe18f28b/browser_use/tools/registry/service.py#L207-L243","documentation":"Error \"{func.__name__}() missing required special parameter '{param.name}'\" thrown in browser-use/browser-use.","triggerScenarios":"A required special (framework-injected) parameter is missing at call time.","commonSituations":"Registry invoked without the agent context that normally injects special parameters.","solutions":["Add the required special parameter to the action signature (e.g., browser_session: BrowserSession)."],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"6c73fced2f6d45a11d88622fe56365a5fe18f28b","analyzedAt":"2026-08-14T19:42:40.557Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}