Jinja Templates

Jinja templates let you build dynamic inputs inside blocks. Anywhere a block field accepts text, you can use Jinja expressions to pull in workflow state, block outputs, environment variables or computed values.

Core Syntax

{{ ... }} for expressions
{% ... %} for control flow


{{ inputs.user_message }}
{{ summarize_block.output }}
{% if inputs.priority == "high" %}urgent{% else %}normal{% endif %}

Variable References

Scout makes three namespaces available in every template:

inputs.field_name: fields from the Input block ({{ inputs.user_name }})
block_id.output: output from a prior block ({{ classify.output }})
_env.VAR_NAME: environment variables for secrets and config ({{ _env.API_KEY }})

Chain dot notation to reach nested fields: {{ fetch_user.output.email }}.

Common Use Cases

Build a prompt with workflow state

Pull user input and a prior block’s output into an LLM prompt:


You are a helpful assistant. The user asked: {{ inputs.question }}

Relevant context from the knowledge base:
{{ retrieval_block.output }}

Answer based only on the context above.

Build an API payload dynamically

Construct a JSON body for an HTTP block:


{
  "user_id": "{{ inputs.user_id }}",
  "action": "{{ inputs.action }}",
  "timestamp": "{{ datetime.now(timezone.utc).isoformat() }}"
}

Conditional messaging

Branch output based on workflow state:


{% if inputs.priority == "high" %}
Urgent: {{ inputs.message }}
{% else %}
FYI: {{ inputs.message }}
{% endif %}

Date and Time

Use __exp_global for simple date strings. Use datetime directly when you need custom formatting:


{# Simple date strings #}
{{ __exp_global.current_date }}
{{ __exp_global.current_datetime }}
{{ __exp_global.current_time_utc }}

{# Custom formatting #}
{{ datetime.now(timezone.utc).isoformat() }}
{{ datetime.now(ZoneInfo("America/Los_Angeles")).strftime('%Y-%m-%d %I:%M %p') }}

Available objects: datetime, timezone, ZoneInfo.

Safe Templating Rules

Reference specific fields, not whole objects. {{ block.output.name }} is safer than {{ block.output }} because it fails loudly if the field is missing.
Keep logic out of templates. If a conditional grows beyond one line, move it into a Conditional block instead.
Test in Console before deploying. Console shows rendered template output so you catch bad references before they hit production.
Use _env for secrets. Never hardcode credentials or tokens in a template.

Next Steps

Logic and State: Understand variable flow and references
Console: Validate rendered template output
Creating Workflows: Build cleaner workflow architectures

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