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Overview Jinja Templating

1. Introduction to Jinja​

Jinja is a templating language for dynamically generating content, commonly used in Python web frameworks like Flask and Django, as well as in YAML files for configuration automation.

Why Use Jinja?​

Dynamic Variables – Insert values into templates without hardcoding.
Conditional Logic – Create templates that adapt based on conditions.
Loops & Filters – Process lists, format data, and apply transformations.
Used in YAML, HTML, JSON, and more – Supports dynamic configuration files.

Basic Jinja Syntax​

Jinja expressions are enclosed in double curly braces ({{ }}) for output, and curly braces with percentage signs ({% %}) for logic.

  • Variables: {{ variable }}
  • Conditions: {% if condition %} ... {% endif %}
  • Loops: {% for item in list %} ... {% endfor %}
  • Filters: {{ variable | filter }}

2. Using Jinja in YAML Configuration Files​

Jinja is commonly used in YAML for configuring automation, API requests, and templated configurations.

Example: Inserting Variables​

api_url: "https://`{{ env.API_HOST }}`"

Example: Using Jinja for Dynamic API Requests​

providers:
  - id: "http"
    config:
      raw_request: |
        POST /detect/jailbreak HTTP/1.1
        Host: `{{ ENV_HOST }}`
        Content-Type: application/json

        {
          "texts": [
            "`{{ prompt }}`"
          ]
        }

3. Jinja Expressions and Filters​

Variables in Jinja​

greeting: "Hello, `{{ user_name }}`!"

4. Jinja Filters​

Common Jinja Filters​

| Filter      | Description                          | Example                                                | Output         |
|-------------|--------------------------------------|--------------------------------------------------------|----------------|
| **lower**   | Converts to lowercase                | `{{ "HELLO" | lower }}`                                | "hello"        |
| **upper**   | Converts to uppercase                | `{{ "hello" | upper }}`                                | "HELLO"        |
| **title**   | Capitalizes first letter of each word| `{{ "hello world" | title }}`                          | "Hello World"  |
| **replace** | Replaces part of a string            | `{{ "error: 404" | replace("error", "status") }}`     | "status: 404"  |
| **default** | Default if variable missing          | `{{ undefined_var | default("N/A") }}`                | "N/A"          |
| **join**    | Joins list to string                 | `{{ ["one", "two", "three"] | join(", ") }}`         | "one, two, three" |
| **length**  | Gets length of string or list        | `{{ "Hello" | length }}`                               | `5`            |
| **int**     | Converts to integer                  | `{{ "42" | int }}`                                     | `42`           |
| **round**   | Rounds numbers                       | `{{ 3.14159 | round(2) }}`                              | `3.14`         |

Example in YAML​

server_name: "`{{ 'myServer' | upper }}`"

5. Jinja Conditionals (if)​

api_host: "{% if env.ENVIRONMENT == 'production' %}api.prod.com{% else %}api.dev.com{% endif %}"

6. Jinja Loops (for)​

Iterating Over a List​

services:
  {% for service in ["database", "cache", "api"] %}
  - "`{{ service }}`"
  {% endfor %}

Iterating with Index​

users:
  {% for user in ["Alice", "Bob", "Charlie"] %}
  - name: "`{{ user }}`"
    id: "`{{ loop.index }}`"
  {% endfor %}

7. Nested Jinja​

servers:
  {% for region in ["us-east", "us-west", "europe"] %}
  - region: "`{{ region }}`"
    host: "{% if region == 'europe' %}eu.server.com{% else %}us.server.com{% endif %}"
  {% endfor %}

8. Jinja in JSON (APIs)​

{
  "users": [
    {% for user in ["Alice", "Bob", "Charlie"] %}
    {
      "name": "`{{ user }}`",
      "id": "`{{ loop.index }}`"
    }{% if not loop.last %},{% endif %}
    {% endfor %}
  ]
}

9. Combining Jinja + JQ​

providers:
  - id: "http"
    config:
      raw_request: |
        POST /api/detect HTTP/1.1
        Host: `{{ ENV_HOST }}`
        Content-Type: application/json

        {
          "texts": [
            "`{{ prompt }}`"
          ]
        }

JQ for Response Transformation​

transform_response: |
  {
    "JAILBREAK": json["results"][0]["chunk_results"][0]["JAILBREAK"],
    "INJECTION": json["results"][0]["chunk_results"][0]["INJECTION"]
  }