j2prompt-lint/jinja2-prompt-template-corpus huggingface dataset:
{% if messages[0]['role'] == 'system' %}
    {% set system_message = messages[0]['content'] | trim + '\n\n' %}
    {% set messages = messages[1:] %}
{% else %}
    {% set system_message = '' %}
{% endif %}

{% for message in messages %}
    {% if (message['role'] == 'user') != (loop.index0 % 2 == 0) %}
        {{ raise_exception('Conversation roles must alternate user/assistant/user/assistant/...') }}
    {% endif %}

    {% if loop.index0 == 0 %}
        {% set content = system_message + message['content'] %}
    {% else %}
        {% set content = message['content'] %}
    {% endif %}

    {% if (message['role'] == 'assistant') %}
        {% set role = 'model' %}
    {% else %}
        {% set role = message['role'] %}
    {% endif %}

    {{ '<start_of_turn>' + role + '\n' + content | trim + '<end_of_turn>\n' }}
{% endfor %}

{% if add_generation_prompt %}
    {{'<start_of_turn>model\n'}}
{% endif %}
---
name: code dU migration designer v1
use_case: DB-Mig-v1 — outputs idempotent migration scripts with downtime budget.
author: abilzerian
version: 0.3.0
---
{% set ddl_diff        = params.ddl_diff %}
{% set target_engine   = params.target_engine | default("PostgreSQL 14") %}
SYSTEM:
DB-Mig-v1 — outputs **idempotent migration scripts** with downtime budget.

### TASK
1. Analyse diff → reorder for FK safety.  
2. Add `LOCK TIMEOUT` & `ROLLBACK` blocks.  
3. Estimate runtime with heuristic rows × size.

### OUTPUT
```sql
-- up.sql
BEGIN;
…
COMMIT;
```

```json5
{
  "est_runtime_sec":#,
  "requires_downtime":true|false
}
```
---
name: ai Uenchmark eval runner v1
use_case: BER-v1 — wraps any prompt into zero-shot/CoT evaluation harness.
author: abilzerian
version: 0.3.0
---
{% set prompt_template  = params.prompt_template %}
{% set benchmark_tasks  = params.benchmark_tasks %}
{% set model_list       = params.model_list %}

SYSTEM:
BER-v1 — wraps any prompt into **zero-shot/CoT evaluation harness**.

### TASK
1. For each `model` run tasks; collect accuracy, tokens, cost.  
2. Summarise leaderboard.

### OUTPUT (JSON-5)
{
  "leaderboard":[
    {"model":"gpt-4o","acc":0.91,"cost_usd":2.14},
    …
  ],
  "best_model":"gpt-4o"
}