Ships the request side of joining a gated scope, completing the §22.8 pair
(S4 shipped the invite half). A user who knows a project/collection exists
asks to join it naming a desired role; the request fans out to that scope's
Owners across the subtree (the cross-collection inbox, §22.11), who accept
(writing the memberships row via memberships.grant) or decline. Built by
analogy to §28 contribution_requests + the S4 memberships surface.
Backend
- migration 032: join_requests (scope_type ∈ {project,collection}, scope_id,
requester, requested_role, message, status, granted_role); one-open-per
(scope, requester) partial unique index. Additive — no rebuild.
- api_join_requests.py: GET join-target / POST join-requests / POST
{id}/accept / {id}/decline under /api/scopes/{scope_type}/{scope_id}/.
Accept grants via memberships.grant; the request POST does not require the
scope be readable (that is how one joins a gated scope).
- notify: fan_out_join_request (subtree-Owner enumeration via
_scope_owner_user_ids), notify_join_decided, 3 render_summary cases.
- auth.effective_role_at_scope — scope-grain twin of effective_scope_role,
folding global → project for a project target.
- api_collections: viewer.can_request_join on the project + collection blocks.
Frontend
- api.js join verbs; JoinRequestModal; "Request to join" affordance in the
collection directory + catalog footer; JoinRequestRow in the inbox.
Tests: backend test_join_requests_vertical (11) + test_migration_032 (5);
frontend api.joinrequests + CollectionDirectory cases. 546 backend / 36
frontend green.
Per docs/design/2026-06-05-three-tier-projects-collections.md Part E (S6) and
SPEC.md §22.8 / §22.11. Closes the request-to-join item flagged open at
0.45.0; per-type surfaces (§22.4a items 1 & 3) remain the last S6 item.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Ben Stull
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