Error Types

Router error type classifications for metrics and expressions

When an error occurs during request processing, the router classifies it into one of the following types. This classification is available via:

• Expressions: request.errorType and subgraph.request.errorType (see Template Expressions)
• Metrics: the wg.error.type OTEL attribute (or wg_error_type in Prometheus)

Value	Description
rate_limit	The request was rejected because the client exceeded the configured rate limit.
unauthorized	The request failed authentication or authorization.
context_canceled	The request was canceled, typically because the client disconnected before the response was sent.
context_timeout	The request timed out before a response could be produced.
upgrade_failed	A WebSocket upgrade request to a subgraph failed.
edfs	An error occurred in a Cosmo Streams (EDFS) data source.
invalid_ws_subprotocol	The client requested an unsupported WebSocket subprotocol.
edfs_invalid_message	A message received from a Cosmo Streams backend could not be parsed as valid JSON.
merge_result	The router failed to merge results from multiple subgraph responses.
streams_handler_error	An error occurred while handling a Cosmo Streams event.
operation_blocked	The operation was rejected by the operation blocker (e.g. blocked operation type or safelist violation).
persisted_operation_not_found	A persisted operation was requested but could not be found.
validation_error	The GraphQL operation failed parsing or validation against the schema.
input_error	The request body was malformed or otherwise invalid (e.g. invalid JSON, missing query).
subgraph_error	One or more subgraphs returned an error during execution.
unknown	An error occurred that does not match any known category.
publish_error	A Cosmo Streams publish operation failed (Kafka, NATS, or Redis). Only appears on stream produce/consume metrics.
request_error	A Cosmo Streams NATS request-reply operation failed. Only appears on stream produce/consume metrics.