Using Kestra Expressions: Pebble Syntax, Filters, and Functions
For the complete documentation index, see llms.txt. For a full content snapshot, see llms-full.txt. Append.mdto anykestra.io/docs/*URL for plain Markdown.
Use expressions to dynamically set values in flows using {{ ... }} syntax backed by the Pebble templating engine.
Common tasks
| If you need to… | Start here |
|---|---|
Access inputs, outputs, vars, trigger, or namespace values | Execution Context |
| Access secrets or credentials at runtime | Data Access Functions |
| Format dates, parse JSON, or transform strings | Filter Reference |
| Render nested expressions or inspect the full context | Rendering Functions |
| Write loops, conditions, fallbacks, and comparisons | Pebble Syntax |
| Build or debug a multiline or nested expression | Pebble Syntax and render() |
Execution Context
Reference for all variables available inside Kestra expressions at runtime — flow metadata, inputs, outputs, trigger values, secrets, and namespace variables.
Pebble Syntax
Complete reference for writing Kestra expressions — delimiters, attribute access, nested rendering, control flow, comparisons, logic operators, and Pebble type tests.
Filter Reference
Complete reference for Kestra Pebble filters — JSON, collections, strings, dates, and YAML. Use filters to transform values with the pipe syntax.
Function Reference
Complete reference for Kestra Pebble functions — rendering, data access, parsing, workflow helpers, utilities, and date/calendar functions.
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