# Core Hub Cutover Decision Coupling

Date: 2026-07-08

Related workplans: `CUST-WP-0025-T17`, `CORE-WP-0005`, `CORE-WP-0007`,
`CUST-WP-0047`, `CUST-WP-0049`.

## Decision Summary

Core Hub is the **preferred production framework surface** for ops evidence and
hub registry work. Haskell Inter-Hub remains available as **rollback-only**
fallback through the stabilization window and until `CORE-WP-0007` operator
sign-off retires it.

| Question | Decision |
| --- | --- |
| Is legacy Inter-Hub still required for normal operation? | **No** — production ingress at `hub.coulomb.social` serves Core Hub since 2026-07-03. |
| Is Inter-Hub fallback still required? | **Yes, rollback-only** until stabilization closes and `CORE-WP-0007-T02` is approved. |
| Are the three cutover gates satisfied? | **Yes** — deployed API smoke, staging import, and activity-core sink evidence all pass. |
| Can Phase 4 fin-hub work begin? | **Yes** — multi-hub pattern is proven at Level 2→3 boundary; fin models remain separate implementation. |

## Readiness Gates

Evidence stubs live under `docs/evidence/` and aggregate through Core Hub
`readiness-summary`:

```bash
cd /home/worsch/core-hub
make operator-cli CLI_ARGS="readiness-summary \
  --deployed-smoke-report /home/worsch/the-custodian/docs/evidence/core-hub-deployed-smoke-20260702235645.json \
  --migration-report /home/worsch/the-custodian/docs/evidence/core-hub-migration-import-20260703.json \
  --activity-core-report /home/worsch/the-custodian/docs/evidence/core-hub-activity-core-sink-20260702.json"
```

Required gates:

| Gate | Status | Evidence |
| --- | --- | --- |
| `deployed_api_smoke` | pass | run `20260702235645-59bf1e` (production); staging `20260702143544-6c8f18` |
| `staging_import` | pass | 28 records imported idempotently; production reconcile 0/28/0 |
| `activity_core_sink` | pass | event `ae43db56-902d-411a-a495-25acd464fdd8` posted and verified |
| `legacy_inter_hub_reference` | optional | retained for rollback validation only |

## Public Stabilization Probes (2026-07-08)

Unauthenticated checks against `https://hub.coulomb.social`:

| Endpoint | Expected | Observed |
| --- | --- | --- |
| `/healthz` | 200 | 200 (`service: core-hub`) |
| `/readyz` | 200 | 200 (`configuration`, `database_url`, `api_auth` ok) |
| `/api/v2/widget-types` | 200 | 200 |
| `/api/v2/hubs` | 401 | 401 (hardened contract) |

## Consumer Compatibility Notes

Consumers migrating from Inter-Hub `/api/v2` must account for:

1. **Auth hardening** — `/api/v2/hubs` is protected on Core Hub. Anonymous
   listing consumers must obtain a token. Audit found no production dependency
   on anonymous 200 responses.
2. **Catalog shape** — Core Hub catalogs use `{name, slug, description}`; Inter-Hub
   used `{name, label, description, ownerHubId, status}`. Parsers must accept
   `slug` as the stable identifier.
3. **Health endpoints** — Core Hub adds `/healthz` and `/readyz`; Inter-Hub
   returned 404 on these paths.
4. **Ops vocabulary** — all 7 orphaned `ops-*` widget types and matching event
   types are seeded in Core Hub before cutover; migrated widgets are referentially
   complete.

## Rollback and Haskell Retirement Gates

Rollback remains one ingress flip:

1. Delete Core Hub ingress (`30-ingress.yaml`)
2. Apply `rollback-inter-hub-ingress.yaml`
3. Inter-Hub deployment stays running untouched through stabilization

`CORE-WP-0007` Haskell retirement requires:

- stabilization window close (through 2026-07-10T17:35Z per workplan)
- operator approval after repeated public probe pass
- explicit decision that rollback is no longer operationally required

## Supersede Decisions

| Legacy task | Superseded by | Date |
| --- | --- | --- |
| `CUST-WP-0047-T05` Inter-Hub widget activation | Core Hub production cutover + deployed smoke | 2026-07-03 |
| `CUST-WP-0049-T06` Inter-Hub bootstrap access lane | Core Hub operator CLI + deployed evidence | 2026-07-03 |

Do not request new Inter-Hub operator keys for the preferred replacement lane.

## Cross-Hub Coupling (FOS §9)

| From | To | Signal |
| --- | --- | --- |
| Core Hub (ops) | dev-hub (State Hub) | progress/decision records, workplan status |
| activity-core | Core Hub | `core-hub-interaction-event` sink |
| fin-hub (future) | dev-hub | budget pressure alerts (T25) |
| fin-hub (future) | Core Hub | per-service cost attribution (T25) |

NATS transport for cross-hub messaging remains a later decision; HTTP evidence
sinks and State Hub progress records are sufficient for the current cutover gate.