Capture and Reuse Execution Results Across Tasks and Flows
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Outputs let you pass data between tasks and flows.

Outputs are stored in the flow’s execution context and accessible by all downstream tasks and flows. Each task defines its own output attributes — see the task’s plugin documentation for details, or inspect them in the Input/Output tab of the Execution page.

Using outputs

Reference a previous task’s output with {{ outputs.<task_id>.<attribute> }} in any dynamic property:

id: task_outputs_example
namespace: company.team


tasks:
  - id: produce_output
    type: io.kestra.plugin.core.debug.Return
    format: my output {{ execution.id }}


  - id: use_output
    type: io.kestra.plugin.core.log.Log
    message: The previous task output is {{ outputs.produce_output.value }}

File outputs are previewable and downloadable from the execution’s Input/Output tab; any output can be inspected and debugged using the built-in expression evaluator on the same tab. See Outputs in the tutorial if you’re unfamiliar with either.

For loop iteration outputs, sibling task outputs, and the loopOutputs() function, see Flowable tasks and the Loop how-to guide.

Internal storage

Tasks that produce large results write them to Kestra’s internal storage and return a URI. Pass that URI to downstream tasks:

id: output_sample
namespace: company.team


tasks:
  - id: output_from_query
    type: io.kestra.plugin.gcp.bigquery.Query
    sql: |
      SELECT * FROM `bigquery-public-data.wikipedia.pageviews_2023`
      WHERE DATE(datehour) = current_date()
      ORDER BY datehour desc, views desc
      LIMIT 10
    store: true


  - id: write_to_csv
    type: io.kestra.plugin.serdes.csv.IonToCsv
    from: "{{ outputs.output_from_query.uri }}"

Flow outputs

Flows can declare strongly typed outputs that are surfaced in the Overview tab and accessible to parent flows via the Subflow task:

id: flow_outputs
namespace: company.team


tasks:
  - id: mytask
    type: io.kestra.plugin.core.debug.Return
    format: this is a task output used as a final flow output


outputs:
  - id: final
    type: STRING
    value: "{{ outputs.mytask.value }}"

Supported output types: ARRAY, BOOLEAN, DATE, DATETIME, DURATION, EMAIL, ENUM, FILE, FLOAT, INT, JSON, MULTISELECT, SECRET, STRING, TIME, URI, YAML.

Pass data between flows

Access a child flow’s declared outputs in the parent via {{ outputs.<subflow_task_id>.outputs.<output_id> }}:

id: parent_flow
namespace: company.team


tasks:
  - id: subflow
    type: io.kestra.plugin.core.flow.Subflow
    flowId: flow_outputs
    namespace: company.team
    wait: true


  - id: log_subflow_output
    type: io.kestra.plugin.core.log.Log
    message: "{{ outputs.subflow.outputs.final }}"

The double outputs is intentional: the first accesses the Subflow task’s outputs, the second accesses the child flow’s declared output final.

Return outputs conditionally

Use a ternary expression to return different outputs based on task state:

id: conditionally_return_output
namespace: company.team


inputs:
  - id: run_task
    type: BOOL
    defaults: true


tasks:
  - id: main
    type: io.kestra.plugin.core.debug.Return
    format: Hello World!
    runIf: "{{ inputs.run_task }}"


  - id: fallback
    type: io.kestra.plugin.core.debug.Return
    format: fallback output


outputs:
  - id: flow_output
    type: STRING
    value: "{{ tasks.main.state != 'SKIPPED' ? outputs.main.value : outputs.fallback.value }}"

Encrypted outputs

Available on:

v>=0.23Enterprise EditionCloud

Script tasks can emit encrypted outputs that are masked in the UI using the encryptedOutputs syntax:

id: encrypted_output
namespace: company.team


tasks:
  - id: hello
    type: io.kestra.plugin.scripts.shell.Script
    script: |
      echo '::{"outputs":{"plaintext":"plaintext_value"}}::'
      echo '::{"encryptedOutputs":{"encrypted":"my secret value"}}::'


  - id: print
    type: io.kestra.plugin.core.log.Log
    message: "{{ outputs.hello['vars']['encrypted'] }}"

The encrypted output is stored and displayed encoded. See Script outputs and metrics for full details.

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