Python SDKFeature Clients

CEL Client

Bases: BaseRestClient

The CEL client is a client for debugging CEL expressions within Hatchet

Methods:

NameDescription
aio_debugDebug a CEL expression with the provided input, filter payload, and optional metadata. Useful for testing and validating CEL expressions and debugging issues in production.
debugDebug a CEL expression with the provided input, filter payload, and optional metadata. Useful for testing and validating CEL expressions and debugging issues in production.

Functions

aio_debug

Debug a CEL expression with the provided input, filter payload, and optional metadata. Useful for testing and validating CEL expressions and debugging issues in production.

Parameters:

NameTypeDescriptionDefault
expressionstrThe CEL expression to debug.required
inputJSONSerializableMappingThe input, which simulates the workflow run input.required
additional_metadataJSONSerializableMapping | NoneAdditional metadata, which simulates metadata that could be sent with an event or a workflow runNone
filter_payloadJSONSerializableMapping | NoneThe filter payload, which simulates a payload set on a previous-created filterNone

Returns:

TypeDescription
CELEvaluationResultA V1CELDebugErrorResponse or V1CELDebugSuccessResponse containing the result of the debug operation.

debug

Debug a CEL expression with the provided input, filter payload, and optional metadata. Useful for testing and validating CEL expressions and debugging issues in production.

Parameters:

NameTypeDescriptionDefault
expressionstrThe CEL expression to debug.required
inputJSONSerializableMappingThe input, which simulates the workflow run input.required
additional_metadataJSONSerializableMapping | NoneAdditional metadata, which simulates metadata that could be sent with an event or a workflow runNone
filter_payloadJSONSerializableMapping | NoneThe filter payload, which simulates a payload set on a previous-created filterNone

Returns:

TypeDescription
CELEvaluationResultA V1CELDebugErrorResponse or V1CELDebugSuccessResponse containing the result of the debug operation.

Raises:

TypeDescription
ValueErrorIf no response is received from the CEL debug API.

Last updated on August 24, 2026

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