flametrench-tenancy 0.3.0

Tenancy primitives for Flametrench: organizations, memberships, and atomic invitation acceptance with the mem_/tup_ duality.

flametrench-tenancy

Python SDK for the Flametrench tenancy specification: organizations, memberships (with the mem_/tup_ duality), and atomic invitation acceptance.

Status: v0.2.0 (stable). Includes the production-ready PostgresTenancyStore alongside the in-memory reference store. Per ADR 0013 the Postgres adapter cooperates with adopter-side outer transactions via savepoints when nested (psycopg3 connection.transaction() handles this automatically).

The same behavioral guarantees that gate @flametrench/tenancy (Node), flametrench/tenancy (PHP), and dev.flametrench:tenancy (Java) hold here:

• Revoke-and-re-add on role changes, with a replaces chain for audit history.
• Sole-owner protection on every path that could leave an org without an active owner (change_role, suspend_membership, self_leave).
• Atomic invitation acceptance — user creation, membership insertion, owner-role tuple, AND pre-tuple expansion all in one transition.
• Role hierarchy on admin_remove — admins cannot remove peers or higher-ranked members.
• mem_/tup_ duality — every active membership is shadowed by a corresponding (usr, role, org) tuple, kept in lockstep with mem.status.

from datetime import datetime, timedelta, timezone

from flametrench_ids import generate
from flametrench_tenancy import InMemoryTenancyStore, PreTuple, Role

store = InMemoryTenancyStore()
alice = generate("usr")
result = store.create_org(alice)
print(result.org.id, result.owner_membership.role)  # → org_..., Role.OWNER

# Invite a new user and pre-attach an editor grant on a project.
project_id = generate("org")[4:]
inv = store.create_invitation(
    org_id=result.org.id,
    identifier="[e-mail]",
    role=Role.MEMBER,
    invited_by=alice,
    expires_at=datetime.now(timezone.utc) + timedelta(days=7),
    pre_tuples=[PreTuple(relation="editor", object_type="proj", object_id=project_id)],
)

out = store.accept_invitation(inv.id)
print(out.membership.role, out.materialized_tuples)

Installation

pip install flametrench-tenancy

Requires Python 3.11+. Depends on flametrench-ids for usr_/org_/mem_/inv_ id generation.

License

Apache-2.0. See LICENSE and NOTICE.

Copyright 2026 NDC Digital, LLC.