---
title: "An automatic rule absorbed a newly-scheduled window into a live series."
method: POST
path: "pass_series.leg_added"
tags: ["pass_series.* events"]
---

# An automatic rule absorbed a newly-scheduled window into a live series.

`POST pass_series.leg_added` (webhook)

### When this fires

A [Pass Series](https://docs.subscriby.net/creators/pass-series) with **Automatic Passes Selection** matched a newly-scheduled window on one of its source plans, added it to the slate, and granted it to everyone currently holding the series, at no extra charge.

This is the event that makes an external calendar or CRM worth wiring up. A season composed with rules is not fixed at the point it sold: it grows, and holders are given what it grows by. Without this you would have to re-read the plan to notice.

> **Holders are messaged too.** Every current holder receives a message on the connector naming the new date, and it appears on their timetable and in their calendar feed. Nothing is asked of them; their invite link arrives before it opens, as usual.

### Caveats

- **This fires once per window.** One absorption run can take in several at a time, which arrives as several events rather than one carrying a list.
- **Absorption respects Prevent Overlapping Passes.** With the toggle on, a window that clashes with something already on the slate is refused rather than absorbed (the series will not hand holders two things at the same time) so a matching window can exist and never produce this event.
- A rule of type `next_n` stops once it has taken its count and **never tops itself back up**. A window becoming free later does not make it reach for another.
- A series is capped at 120 dates. A rule that would take the slate past the cap stops there.
- Holders who cancelled are not granted the new date.
- Manually handpicked dates never produce this event. Handpicking is a fixed list by design; only rules keep working after the save.
- A date the creator has excluded stays excluded. Unticking a rule-added pass records a permanent exclusion, and the rule will not put it back.

### Related events

- `pass.window_scheduled`: the window coming into existence, which is what a rule reacts to.
- `pass_series.leg_substituted`: a date being swapped rather than added.
- `pass_series.leg_dropped`: a date leaving a season.

## Headers

- `SB-Signature` string, required
- `SB-Event-Id` string, required
- `SB-Event-Name` string, required
- `Content-Type` string, required
- `User-Agent` string, required

## Payload

- object: The envelope every event is delivered in.
  - `id` string, required: A ULID unique to the event, prefixed `evt_`. Every retry carries the same id, so it is the key to deduplicate on.
  - `type` 'pass_series.leg_added', required: The event name, always `pass_series.leg_added` here.
  - `created_at` string, date-time, required: When the event was emitted, server time, ISO 8601.
  - `api_version` string, required: The contract version of the payload shape, `2026-05-01` today. A breaking change to a shape ships under a new version.
  - `project_id` string, uuid, nullable, required: The project the event belongs to; null for team-scoped and billing events.
  - `data` object, required: The event-specific payload. Keys that do not apply to a given emission are omitted rather than sent as null, so check for presence.
    - `plan_id` string, uuid, required: The **series** plan that grew.
    - `plan_name` string, required: Its name.
    - `window_id` string, uuid, required: The window that was absorbed.
    - `source_plan_id` string, uuid, required: The pass plan the window belongs to. This is the plan whose resources that date grants.
    - `starts_at` string, date-time, required: Window start, **always UTC**.
    - `ends_at` string, date-time, required: Window end, always UTC.
    - `timezone` string, required: The **source plan's** authoring zone; a series has none of its own. Render the timestamps in this.
    - `window_count` integer, required: The slate's total length after this absorption.

## Acknowledgement `2XX`

Your endpoint acknowledged the delivery. Any 2xx status within 30 seconds marks it delivered; the response body is ignored.

## Other responses

- `default`: Any other status, a connection failure, or no answer within 30 seconds counts as a failed attempt. The delivery is retried 8 times, after 10 seconds, 30 seconds, 2 minutes, 10 minutes, 1 hour, 6 hours, 1 day, 3 days; the last failure dead-letters it, and it can be retried from the dashboard or `POST /v1/webhook-deliveries/{delivery}/retry`. After 20 consecutive failures the endpoint is paused until it is resumed.

---

[API](https://skmtc.dev/memberpass/apis/subscriby-rest-api.md) · [All operations](https://skmtc.dev/memberpass/apis/subscriby-rest-api/llms.txt) · [OpenAPI document](https://skmtc.dev/memberpass/apis/subscriby-rest-api/revisions/59c4df91d764?raw)