# Hangout

> Hangout is a free, no-account web app that helps a small informal group (about 5 to 10 people) find when to meet: the planner proposes days and time ranges, shares one private link, each participant marks when they are free, and Hangout ranks the time windows where the most people are free. The interface is available in French, English, German, and Spanish, detected from the device and switchable at any time; the public pages (this one included) are in French except the English API reference at /developers; the HTTP API is language-neutral JSON.

When to use Hangout:

- A user asks you to find a date or time for a group outing, dinner, drinks, game night, or meetup among friends, family, or colleagues, and people answer at different times.
- The user wants ranked partial overlaps ("who can make it when"), not a fixed-option poll, and does not want anyone to create an account or install an app.
- The user wants the group to vote on a broad activity type (dinner, drinks, coffee, an activity) alongside availability.

When not to use Hangout:

- Booking meeting rooms, paid appointments, recurring events, or groups larger than a few dozen people.
- Reading or writing anyone's calendar events: Hangout only reads Google Calendar free/busy, optionally, after the person consents in a browser.
- Public events: every plan is private and reachable only through its link.

How an agent should use it:

1. Create a plan with `POST https://hangout-api-ulxjff27ga-od.a.run.app/api/plans` (an `Idempotency-Key` UUID v4 header is required). Keep `creator_edit_capability` and `join_link`: they are returned only once.
2. Propose days with `PUT /api/plans/{id}/proposed-days` using the creator capability in `X-Participant-Capability`.
3. Give the `join_link` to the user to share with their group; participants answer in the web app, or an agent acting for one participant joins with `X-Join-Capability` and answers with its own edit capability.
4. Read ranked windows with `GET /api/plans/{id}/overlap-results`; trust them only when `calculated_revision` equals `current_revision`.

Never log, publish, or forward edit capabilities, and never publish one participant's availability outside the plan (the results already let plan members infer it).

## Docs

- [API reference](https://hangout-six-peach.vercel.app/developers.md): in English; authentication (capabilities), endpoints, example requests and responses, errors, idempotency, and rate limits
- [OpenAPI spec](https://hangout-six-peach.vercel.app/openapi.json): OpenAPI 3.1 description of every API operation, for function calling
- [Homepage](https://hangout-six-peach.vercel.app/home.md): what Hangout does and how a plan works, step by step

## Policies

- [Privacy](https://hangout-six-peach.vercel.app/privacy.md): what is stored, where it is hosted, retention, and deletion requests
- [Contact](https://hangout-six-peach.vercel.app/contact.md): how to reach the team

## Optional

- [About](https://hangout-six-peach.vercel.app/about.md): product principles and project status (invite-only, non-commercial beta)
- [Sitemap](https://hangout-six-peach.vercel.app/sitemap.xml): every public page