> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getlago.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Helpers

> Raw API access, aliases, demo data, scripted fixtures, and a live tail of API logs.

| Command                        | Description                                                                |
| ------------------------------ | -------------------------------------------------------------------------- |
| `lago api METHOD PATH`         | Authenticated request to any endpoint.                                     |
| `lago docs <resource>`         | Open the API reference for a resource in the browser.                      |
| `lago alias set\|list\|delete` | User-defined command shortcuts, stored in the config file.                 |
| `lago seed demo`               | Create a metric, plan, customer, subscription, event, and invoice preview. |
| `lago fixtures run FILE`       | Run a YAML scenario with variable capture between steps.                   |
| `lago logs tail`               | Poll API request logs and re-render on change.                             |

## api

Same profile, redaction, retries, and output handling as the generated commands. Use it for endpoints newer than the CLI's embedded spec. The `/api/v1` prefix is optional and never doubled. Destructive paths are confirmation-gated here too.

| Flag             | Description                                   |
| ---------------- | --------------------------------------------- |
| `--data`, `-d`   | Body: inline JSON, `@file`, or `-` for stdin. |
| `--header`, `-H` | Extra header. Repeatable.                     |

## alias

An alias expands in place, so any flags after it pass through.

## seed and fixtures

`seed demo` prefixes everything it creates (`demo` by default) so the data is easy to find and delete. `fixtures run` executes ordered API steps from YAML: `${var}` interpolation, `capture` to lift a value from one response into the next. Give events a `transaction_id` so a re-run does not double count. `--dry-run` prints every request and sends none.

## logs tail

Filters are `--method` (repeatable), `--status` (a code or a class such as `4xx`, repeatable), `--resource` (path prefix), and `--interval`.

<RequestExample>
  ```bash api theme={"dark"}
  lago api GET /customers?page=2
  lago api GET /api/v1/customers                    # same request
  lago api POST /events --data @event.json
  printf '{"event":{"code":"api_calls","external_subscription_id":"sub_1"}}' \
    | lago api POST /events --data -
  lago api GET /customers -H "X-Trace: qa-run-12"
  ```

  ```bash docs theme={"dark"}
  lago docs customers
  lago docs billable-metrics
  ```

  ```bash alias theme={"dark"}
  lago alias set cust "customers"
  lago alias set inv-open "invoices list --statuses finalized --payment-statuses pending"
  lago alias list
  lago alias delete cust

  lago cust list --limit 5    # expands to: lago customers list --limit 5
  ```

  ```bash seed theme={"dark"}
  lago seed demo
  lago seed demo --prefix local-demo --output json
  ```

  ```bash fixtures theme={"dark"}
  lago fixtures run scenario.yaml
  lago fixtures run scenario.yaml --var prefix=qa --var currency=EUR
  lago fixtures run scenario.yaml --var prefix=qa --dry-run
  ```

  ```bash logs tail theme={"dark"}
  lago logs tail
  lago logs tail --status 4xx --resource /customers --method POST
  lago logs tail --status 500 --status 502 --interval 5s
  ```
</RequestExample>

<ResponseExample>
  ```text api (dry run) theme={"dark"}
  BODY     {"event":{"code":"api_calls","external_subscription_id":"sub_1"}}
  HEADERS  {"Accept":["application/json"],"Authorization":["Bearer [REDACTED]"],"Content-Type":["application/json"],"Idempotency-Key":["event-42"],"User-Agent":["lago-cli/1.0.0"]}
  METHOD   POST
  URL      https://api.getlago.com/api/v1/events
  ```

  ```yaml scenario.yaml theme={"dark"}
  version: 1
  name: lago-demo
  vars:
    prefix: demo
  steps:
    - id: metric
      method: POST
      path: /billable_metrics
      body:
        billable_metric:
          name: Demo requests
          code: ${prefix}-requests
          aggregation_type: count_agg
      capture:
        metric_id: billable_metric.lago_id
    - id: plan
      method: POST
      path: /plans
      body:
        plan:
          name: Demo usage plan
          code: ${prefix}-plan
          interval: monthly
          amount_cents: 0
          amount_currency: USD
          pay_in_advance: false
          charges:
            - billable_metric_id: ${metric_id}
              charge_model: standard
              properties:
                amount: "1"
      capture:
        plan_code: plan.code
    - id: customer
      method: POST
      path: /customers
      body:
        customer:
          external_id: ${prefix}-customer
          name: Demo Customer
          currency: USD
      capture:
        customer_id: customer.external_id
    - id: subscription
      method: POST
      path: /subscriptions
      body:
        subscription:
          external_customer_id: ${customer_id}
          external_id: ${prefix}-subscription
          plan_code: ${plan_code}
      capture:
        subscription_id: subscription.external_id
    - id: event
      method: POST
      path: /events
      body:
        event:
          transaction_id: ${prefix}-event-1
          external_subscription_id: ${subscription_id}
          code: ${prefix}-requests
    - id: invoice-preview
      method: POST
      path: /invoices/preview
      body:
        customer:
          external_id: ${customer_id}
        subscriptions:
          external_ids:
            - ${subscription_id}
      capture:
        invoice_total_cents: invoice.total_amount_cents
        invoice_currency: invoice.currency
  ```

  ```toml config.toml aliases theme={"dark"}
  [aliases]
  cust = ["customers"]
  inv-open = ["invoices", "list", "--statuses", "finalized", "--payment-statuses", "pending"]
  ```
</ResponseExample>