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Variables make your Blueprint Blueprints reusable. Instead of hardcoding values like usernames, API keys, or article text directly into node configurations, you define named placeholders and supply the actual values when you run the Blueprint. Every node configuration field that accepts text also accepts variable references, so a single Blueprint can power many different use cases.

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Variable syntax

Reference a variable anywhere in a node configuration using double curly braces:
Plain Text Variable names are case-sensitive and may contain letters, numbers, and underscores. Spaces are not allowed. Valid examples
Plain Text In a node configuration field
JSON When the Blueprint runs, Blueprint replaces each {{variable_name}} token with the supplied value before the node executes.

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Types of variables

Blueprint supports two kinds of variables that work together:
  • Runtime variables
  • Environment variables
Runtime variables are values you pass each time you trigger a Blueprint execution. They are transient — they exist only for the duration of that run and are not stored on the Blueprint itself. Use runtime variables for content that changes per run: user-provided text, dynamic IDs, dates, or any input that should not be persisted. How to supply them
  • Web UI: Fill in the variables form that appears when you click Run.
  • API: Include a variables object in your execute request body.
  • CLI: Pass a JSON string with the --inputs flag.
Environment variables are stored on the Blueprint and are available to every execution without needing to be passed at run time. They are ideal for secrets, API keys, and configuration that remains constant across runs. 1 Open Blueprint settings In the Blueprint editor, click the Settings tab in the left sidebar. 2 Add an environment variable Under Environment variables, click Add variable. Enter a name (e.g. OPENAI_API_KEY) and its value. 3 Reference in node configs Use {{OPENAI_API_KEY}} in any node configuration field. The value is substituted at execution time without being exposed in the Blueprint map.

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Defining variables in the editor

You can declare expected runtime variables directly on the Blueprint so the web UI knows what inputs to prompt for: 1 Open the Variables panel In the Blueprint editor, click the Variables icon in the left toolbar (or press V). 2 Add a variable definition Click + Add variable and fill in:
  • Name — the identifier used in {{variable_name}} syntax
  • Type — string, number, boolean, or json
  • Default value (optional) — used when no value is supplied at run time
  • Description (optional) — shown as a hint in the run dialog
3 Use the variable in nodes Type {{ inside any node configuration field to see an autocomplete list of defined variables.

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Passing variables at execution time

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Via the API

Include the variables key in the request body when calling the execute endpoint:
JSON The values can be strings, numbers, booleans, arrays, or nested objects. Blueprint serialises non-string types to JSON before substituting them into text fields.

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Via the CLI

bash

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Via the web UI

Click Run on any Blueprint. If the Blueprint has declared variables, the run dialog displays a form with a field for each one. Fill in the values and click Execute.

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Referencing node output

In addition to named variables, you can pass the output of any upstream node into a downstream node’s configuration using the node’s output reference:
Plain Text Blueprint resolves these references after each node completes, so every downstream node has access to all prior outputs.