Kestra Expressions Guide – Pebble and Context Variables
Use expressions to dynamically set values in flows using {{ ... }} syntax backed by the Pebble templating engine.
Find the right expressions doc
- Start with Execution Context Variables if you need to know what values are available in flows.
- Go to Pebble Syntax if you need help writing expressions.
- Use Filter Reference when you know you need a filter but are not sure which category it belongs to.
- Use Function Reference for runtime helpers such as
render(),secret(),read(), andprintContext(). - Use Operators, Tags, and Tests for control flow and boolean logic.
Common tasks
| If you need to… | Start here |
|---|---|
Access inputs, outputs, vars, trigger, or namespace values | Execution Context Variables |
| Format dates, parse JSON, or transform strings | Filter Reference |
| Render nested expressions or inspect the full context | Function Reference |
| Write loops, conditions, fallbacks, and comparisons | Pebble Syntax and Operators, Tags, and Tests |
| Build or debug a multiline or nested expression | Pebble Syntax and Function Reference |
Browse expressions docs
Execution Context Variables
Learn which variables are available in Kestra expressions, including flow metadata, inputs, outputs, triggers, namespace values, environment variables, and secrets.
Pebble Syntax
Learn the core Pebble templating syntax used in Kestra expressions, including delimiters, attribute access, control structures, macros, and null handling.
Filter Reference
Reference guide to the most important Kestra expression filters, grouped by data type and common use case.
Function Reference
Reference guide to the main functions available in Kestra expressions, including rendering, secrets, file access, debugging, and utility helpers.
Operators, Tags, and Tests
Learn the operators, tags, and tests used in Kestra expressions for comparisons, control flow, loops, fallbacks, and template logic.
Was this page helpful?