{"record":{"id":"2b73f7ef564bc4f0","repo":"vllm-project/vllm","slug":"kind-parsing-is-disabled-by-frontend-configurati","errorCode":null,"errorMessage":"{kind} parsing is disabled by frontend configuration","messagePattern":"(.+?) parsing is disabled by frontend configuration","errorType":"exception","errorClass":"Error","httpStatus":null,"severity":"error","filePath":"rust/src/chat/src/error.rs","lineNumber":35,"sourceCode":"    MissingChatTemplate,\n    #[error(\"chat template error: {0}\")]\n    ChatTemplate(String),\n    #[error(\"multimodal input is not supported by this chat renderer\")]\n    UnsupportedMultimodalRenderer,\n    #[error(\"unsupported multimodal content: {0}\")]\n    UnsupportedMultimodalContent(&'static str),\n    #[error(\"`{modality}` input is not supported by this model\")]\n    UnsupportedModality { modality: String },\n    #[error(\"At most {limit} {modality}(s) may be provided in one prompt.\")]\n    MmLimitExceeded { modality: String, limit: usize },\n    #[error(\"multimodal preprocessing error: {0}\")]\n    Multimodal(#[message] String),\n    #[error(\"{kind} parsing is not available for model `{model_id}`\")]\n    ParserUnavailableForModel {\n        kind: &'static str,\n        model_id: String,\n    },\n    #[error(\"{kind} parsing is disabled by frontend configuration\")]\n    ParserDisabled { kind: &'static str },\n    #[error(\n        \"{kind} parser `{name}` is not registered{}\",\n        available_parser_hint(.available_names)\n    )]\n    ParserUnavailableByName {\n        kind: &'static str,\n        name: String,\n        available_names: Vec<String>,\n    },\n    #[error(\"failed to initialize {kind} parser `{name}`\")]\n    ParserInitialization {\n        kind: &'static str,\n        name: String,\n        #[source]\n        error: BoxedError,\n    },\n    #[error(","sourceCodeStart":17,"sourceCodeEnd":53,"githubUrl":"https://github.com/vllm-project/vllm/blob/c794754062d49a8fdb63ab3c5215b488b865030c/rust/src/chat/src/error.rs#L17-L53","documentation":"EventPublisherFactory resolves the publisher kind from kv_events_config.publisher against a registry containing only 'null' and 'zmq' by default. The configured kind has no registered constructor, so no event publisher can be built.","triggerScenarios":"Setting --kv-events-config publisher to a string other than 'null'/'zmq' (e.g. 'kafka', 'redis'); a publisher registered via register_publisher under a different name than configured; type Literal['null','zmq'] bypassed via raw dict/env config.","commonSituations":"Expecting a built-in publisher that does not exist in this vLLM version; plugin registered after config parsing or in a different process than the one constructing the publisher; typos in config files.","solutions":["Use publisher='zmq' (the only built-in external publisher) or 'null' to disable","For a custom publisher, register it with EventPublisherFactory.register_publisher(name, ctor) in the same process before the engine builds the publisher, and set publisher to that exact name","Check EventPublisherFactory._registry keys at startup to confirm which kinds are available"],"exampleFix":"# before\npublisher = \"kafka\"  # not registered\n\n# after\nfrom vllm.distributed.kv_events import EventPublisherFactory, ZmqEventPublisher\nEventPublisherFactory.register_publisher(\"myzmq\", ZmqEventPublisher)\npublisher = \"myzmq\"","handlingStrategy":"validation","validationCode":"from vllm.distributed.kv_events import EventPublisherFactory\nkind = kv_events_config.publisher\nassert kind in EventPublisherFactory._registry, f'unknown publisher {kind}; registered: {list(EventPublisherFactory._registry)}'","typeGuard":"def is_registered_publisher(kind: str) -> bool:\n    from vllm.distributed.kv_events import EventPublisherFactory\n    return kind in EventPublisherFactory._registry","tryCatchPattern":null,"preventionTips":["Stick to built-in 'null'/'zmq' unless a plugin is registered","Register custom publishers in the same process before engine startup","Validate publisher names against the registry during config validation"],"tags":["kv-events","publisher","registry","config","vllm"],"backgroundTag":null,"analyzedSha":"c794754062d49a8fdb63ab3c5215b488b865030c","analyzedAt":"2026-08-14T21:17:39.825Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}