request group join
horizon_request_group_joinConfirms a player's explicit group join request using the exact reviewed group revision, atomically creating the join request and leader Inbox notice.
Instructions
Applies the explicit request group join action using the reviewed group revision. Use when: the player explicitly confirms this group action. Not for: replacing reviewed revisions/request IDs, bypassing a leader's block, or retrying automatically after uncertainty. Requires: userId and the player's session: sign in with horizon_signin_email or horizon_signin_anonymous and pass its accessToken as sessionToken. Current group revision and the exact pending requestId where applicable. Side effects: Creates a join request and ordinary leader Inbox notice atomically. No automatic retry. Same-revision replay cannot create a second effect. Returns: {groups:MyGroupsView,group:GroupView|null}. groups is the actor's complete snapshot, never the target's private state. group is null after leave/delete; nonmembers never receive private data. Replace only the matching host/project/player cache. Errors: Use horizon_get_groups and horizon_get_group_pending to reconcile state. 409 REVISION_CONFLICT or uncertain response: read and reconcile intent, never refresh the revision and repeat automatically. Pending decisions require the original requestId; REQUEST_NOT_FOUND means it was removed/replaced. INBOX_FULL rolls back the entire action. 403 rejects group role, session or bilateral block violations. 429 is reported without automatic retry. 401 means the session is missing or expired: sign in again and retry with the new accessToken. 403 for a session means the token belongs to another user: pass the userId that signed in. Needs HORIZON_API_KEY. Every failure returns an error result (isError) with the HTTP status and body: a 401 that horizon_test_connection also returns means HORIZON_API_KEY is wrong, 429 means the account's per-minute rate limit was reached (wait a minute, then retry).
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| userId | Yes | Signed-in player matching the Bearer session | |
| groupId | Yes | Exact group UUID in the current project; never an authorization credential | |
| sessionToken | Yes | Player accessToken, sent only in Authorization | |
| expectedRevision | Yes | Exact reviewed revision; never replace automatically after an uncertain response |