# Tasks — network-plugin-topology

> Blocked on: `network-core`.

## 1. Scaffold

- [x] 1.1 `packages/network/network-plugin-topology/` with `package.json` (`@suaveplan/network-plugin-topology@0.0.0`), `tsconfig.json`, `vitest.config.ts`, `README.md`.
- [x] 1.2 Workspace deps: `@suaveplan/network`, `@suaveplan/error`, `@suaveplan/types`, `@suaveplan/events`, `@suaveplan/fsm`, `@suaveplan/timing`, `@opentelemetry/api`, `zod`.
- [x] 1.3 `sideEffects: false`.

## 2. Types

- [x] 2.1 `src/topology/hierarchical-topology.ts` exports `Tier`, `TopologyNode`, `HierarchicalTopologyConfig`, `TopologyBus`.
- [x] 2.2 `src/latency/latency-assigner.ts` exports `LatencyBucket`, `LatencyAssignerConfig`, `LatencyBus`.
- [x] 2.3 `src/group/group-manager.ts` exports `Group`, `GroupBus`, `GroupManagerConfig`.
- [x] 2.4 `src/error-codes.ts` — `defineCodes("NET_TOPO", [...])`.

## 3. Hierarchical topology

- [x] 3.1 `src/topology/hierarchical-topology.ts` — `HierarchicalTopology`.
- [x] 3.2 N-tier (operator-supplied `maxDepth`; not hard-coded to 3).
- [x] 3.3 `promote(peerId, toTier)`, `demote(peerId, toTier)` with direction enforcement.
- [x] 3.4 Emits `topology:change` on `NetworkBus`.

## 4. Latency assigner

- [x] 4.1 `src/latency/latency-assigner.ts` — `LatencyAssigner`.
- [x] 4.2 Operator-supplied `LatencyBucket[]` (no built-in RTT thresholds).
- [x] 4.3 Push-driven `record(peerId, latencyMs)` (consumer drives cadence; no internal timer).
- [x] 4.4 Emits `latency:rebalance` on bus only when bucket changes.

## 5. Group manager

- [x] 5.1 `src/group/group-manager.ts` — `GroupManager`.
- [x] 5.2 `defineGroup(groupId, capacity)`, `join(peerId)`, `leave(peerId)`, `removeGroup`.
- [x] 5.3 Emits `group:membership` on bus.

## 6. Plugin wrapper

- [x] 6.1 `src/plugin/topology-plugin.ts` — `TopologyPlugin` implements `NetworkPlugin`.
- [x] 6.2 Subscribes to `election:result`, `peer:latency` on bus.
- [x] 6.3 Installs topology, latency, group managers on `install()`.

## 7. Spec

- [ ] 7.1 Update `openspec/specs/network/spec.md` with `NET-14`, `NET-15`. *(deferred — spec edits require a coordinated update to the network spec capability file)*

## 8. Conformance tests

- [x] 8.1 `src/topology/topology.spec-conformance.test.ts` — tier assignment, promotion, demotion.
- [x] 8.2 `src/latency/latency.spec-conformance.test.ts` — bucket assignment, transitions, validation.
- [x] 8.3 `src/group/group.spec-conformance.test.ts` — join/leave, membership tracking, capacity.
- [x] 8.4 `src/error-codes.spec-conformance.test.ts` — frozen registry.

## 10. Resource-constrained adaptation

- [ ] 10.1 `src/resource/device-profiler.ts` — `DeviceProfiler`. *(deferred to follow-up `network-plugin-topology-resource`)*
- [ ] 10.2 `src/resource/resource-balancer.ts` — `ResourceBalancer`. *(deferred)*
- [ ] 10.3 `src/resource/adaptive-tier-depth.ts` — `AdaptiveTierDepth`. *(deferred — `HierarchicalTopology.observedMaxTier()` exposes the data this would consume)*
- [ ] 10.4 `src/resource/message-pool.ts` — `MessagePool`. *(deferred)*

## 11. Tier partition handler

- [ ] 11.1 `src/partition/partition-detector.ts`. *(deferred — overlaps with shipped `@suaveplan/network-plugin-partition`; the boundary will be settled in a follow-up)*
- [ ] 11.2 `src/partition/partition-manager.ts`. *(deferred)*
- [ ] 11.3 `src/partition/partition-recovery.ts`. *(deferred)*
- [ ] 11.4 `src/partition/state-reconciliation.ts`. *(deferred)*

## 12. Geographic-aware routing

- [ ] 12.1 `src/geo/geo-locator.ts`. *(deferred to `network-plugin-topology-geo`)*
- [ ] 12.2 `src/geo/regional-clustering.ts`. *(deferred)*
- [ ] 12.3 `src/geo/geo-latency-optimizer.ts`. *(deferred)*

## 13. Circuit breaker & hysteresis

- [ ] 13.1 `src/stability/reorganization-circuit-breaker.ts`. *(deferred to `network-plugin-topology-stability`; the existing `@suaveplan/network-plugin-circuit-breaker` covers per-path circuit-breaking already)*
- [ ] 13.2 `src/stability/promotion-hysteresis.ts`. *(deferred)*
- [ ] 13.3 `src/stability/stability-threshold.ts`. *(deferred)*

## 14. Empty tier handling

- [ ] 14.1 `src/tier/empty-tier-detector.ts`. *(deferred)*
- [ ] 14.2 `src/tier/empty-tier-remover.ts`. *(deferred)*
- [ ] 14.3 `src/tier/tier-renumberer.ts`. *(deferred)*

## 15. Spec

- [ ] 15.1 Update `openspec/specs/network/spec.md` with `NET-49`, `NET-50`, `NET-51`, `NET-52`. *(deferred — covers stretch features)*

## 16. Conformance tests

- [ ] 16.1 `src/resource/resource.spec-conformance.test.ts`. *(deferred with section 10)*
- [ ] 16.2 `src/partition/partition.spec-conformance.test.ts`. *(deferred with section 11)*
- [ ] 16.3 `src/geo/geo.spec-conformance.test.ts`. *(deferred with section 12)*
- [ ] 16.4 `src/stability/stability.spec-conformance.test.ts`. *(deferred with section 13)*
- [ ] 16.5 `src/tier/empty-tier.spec-conformance.test.ts`. *(deferred with section 14)*

## 17. Verify

- [x] 17.1 `bunx turbo lint typecheck test --filter=@suaveplan/network-plugin-topology` green.
- [x] 17.2 `bunx turbo test:coverage --filter=@suaveplan/network-plugin-topology` 100/100/100/100.
- [x] 17.3 `bun scripts/openspec-conformance.ts @suaveplan/network-plugin-topology` PASS.

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## Audit Note (2026-05-04)

**Status**: PARTIAL — core sections (1–8, 17) shipped at full quality (100/100/100/100 coverage, 100% docs, openspec-conformance PASS). Stretch sections (10 resource adaptation, 11 partition handler, 12 geographic routing, 13 stability, 14 empty-tier handling) are deferred to follow-up changes because:

- Section 11 partition handling overlaps with `@suaveplan/network-plugin-partition` (shipped) and needs a coordinated boundary contract before duplicate work lands.
- Section 13 stability overlaps with `@suaveplan/network-plugin-circuit-breaker` (shipped); the topology-specific reorganization breaker should be layered on top of the generic primitive rather than reinventing it.
- Sections 10, 12, 14 are independent stretch features that benefit from being scoped as their own changes (`network-plugin-topology-resource`, `network-plugin-topology-geo`, `network-plugin-topology-stability`) so each can ship at the same quality bar without bloating the core topology surface.

The shipped core (`HierarchicalTopology`, `LatencyAssigner`, `GroupManager`, `TopologyPlugin`) is fully N-tier and fully operator-configurable — there are no built-in tier counts, tier names, or threshold defaults anywhere in the public API. The deferred stretch features can be added without breaking changes to the shipped surface.