Wire the mutator and web API into the service bus so live-topology
edits flow sub-second from enqueue to UI:
- Mutator publishes every state transition on the bus (mutation.applying
/applied/failed + topology.status). Fire-and-forget; DB stays source
of truth.
- Mutator watch loop subscribes to topology.*.mutation.enqueued and
wakes early via asyncio.Event — the 10s poll becomes a fallback
heartbeat, not the primary dispatch trigger.
- POST /topologies/{id}/mutations publishes mutation.enqueued after
the DB write succeeds.
- New GET /topologies/{id}/events SSE route: snapshot on connect
(status + in-flight mutations), live forwards topology.{id}.>
bus events, 15s keepalive. ?token= auth mirrors /stream.
- New decnet/bus/app.py — process-wide lazy bus singleton for the
API, closed cleanly on lifespan shutdown.
Active/degraded/failed/deploying topologies cannot be deleted
without first transitioning to torn_down, but the UI had no way
to trigger that. Add POST /topologies/{id}/teardown mirroring the
deploy endpoint (background task, 202 Accepted), and a
click-to-arm TEARDOWN button on the topology list card that shows
whenever the row is in a teardown-eligible state.
GET /api/v1/topologies — paginated list with status filter. Extends
repo.list_topologies() to accept limit/offset and adds count_topologies()
for the total envelope field.
GET /api/v1/topologies/{id} — hydrated TopologyDetail; 404 if missing.
GET /api/v1/topologies/{id}/status-events — audit trail, limit-capped.
Catalog helpers for the phase-4 canvas UI:
* GET /topologies/services — full service catalog.
* GET /topologies/next-subnet?base=172.20 — wraps SubnetAllocator against
reserved_subnets across non-torn-down topologies.
* GET /topologies/{id}/lans/{lan_id}/next-ip — IPAllocator pre-seeded
with existing decky IPs in that LAN.
All read routes are viewer-or-admin. Sub-routers are included in an
order that keeps literal catalog paths (/services, /next-subnet) from
being shadowed by the /{topology_id} trie branch.
Add Pydantic DTOs in decnet/web/db/models.py covering every phase-3
endpoint shape: TopologyGenerateRequest, TopologySummary/Detail, child
create/update requests, MutationEnqueueRequest (Literal op guard),
MutationRow with JSON-payload decoder, validation/version/not-editable
error envelopes, and the three catalog responses.
Create decnet/web/router/topology/ as an import-safe package exporting
topology_router (prefix /topologies) — sub-routers land step-by-step in
subsequent commits. Mount under the main api router alongside swarm_mgmt.
tests/api/topology/test_models.py pins repo-dict ↔ DTO parity so future
repo-row drift breaks the contract test before the endpoints.
