# M7.10 — M7 composition gate — source connectors

| Field | Value |
|---|---|
| Phase | M7 — Source connectors |
| Size | M — 1–3 days |
| Status | ⬜ Not started |
| Flags | gate |
| Spec | inlined below |
| Blocks | — |
| Depends | M7.1, M7.2, M7.3, M7.6, M7.7, M7.8, M7.9 |

## Goal

Prove the connector framework composes: two different connector kinds sync
through the same framework, change detection skips unchanged documents, tombstoning
works, drift reports are accurate, rebuild parity holds, and the gated loop's
update-rate is untouched.

## What the gate proves

1. **Extensibility works.** Two different connector kinds (at minimum: obsidian +
   one remote connector) register, sync, and produce queryable Level R content
   through the same `SyncEngine`. No connector-specific code exists outside the
   connector itself.

2. **Change detection is efficient.** Re-syncing an unchanged connector produces
   zero embedding calls. This is the cost guard — without it, every sync is a
   full re-embed.

3. **Tombstoning is correct.** Removing a document from a source results in
   tombstone records in the log, removal from the index, and correct behavior
   on rebuild.

4. **Drift report is read-only.** Running `mem source status` mutates nothing.

5. **Rebuild parity holds for connectors.** `mem rebuild --from-log` with
   connector-sourced data produces byte-identical results.

6. **Update-rate is untouched.** Adding connector-sourced reference documents
   does not change the gated loop's update-rate (same property M3.6.6 asserts,
   now for any connector).

7. **Health monitoring detects failures.** An unreachable connector is reported,
   not silently ignored.

## Verify

**Integration test** — `tests/it_m7_gate.rs`:

1. `a1_two_kinds_sync` — register an obsidian + vec connector; sync both; assert
   Level R nodes exist for both sources.
2. `a2_unchanged_zero_embeds` — re-sync both; assert zero embedding calls.
3. `a3_change_detected_and_replaced` — modify a doc in one connector; sync;
   assert old chunks tombstoned, new chunks present.
4. `a4_removal_tombstoned` — remove a doc; sync; assert tombstone records and
   doc absent from query results.
5. `a5_drift_report_is_read_only` — snapshot log + manifest; run status; assert
   unchanged.
6. `a6_rebuild_parity` — after full sync, rebuild from log; assert byte-identical
   state.
7. `a7_update_rate_untouched` — record update-rate before adding connectors;
   add connectors + sync; re-run gated loop; assert update-rate unchanged.
8. `a8_health_failure_reported` — configure unreachable connector; assert
   health check reports failure.
9. `a9_no_connector_specific_code_in_sync` — assert `SyncEngine` has no
   `match kind` or `if kind ==` statements (the trait is the dispatch, not
   the framework).
10. `a10_query_returns_connector_content` — sync a connector; query its content;
    assert results include connector-sourced Level R nodes with correct source_uri.

**Command:** `cargo test --test it_m7_gate`

**False pass:**
- Testing with only one connector kind. The gate's value is proving two
  *different* kinds work through the same framework.
- Testing rebuild parity without connector data in the log. An empty log
  trivially rebuilds.
- Asserting update-rate "is still below 30%" instead of "is unchanged". Adding
  reference docs should not move the number at all.

## Traps

- Running the gate before M7.6 (sync framework) is solid. The gate tests
  composition; if the sync framework has bugs, every gate assertion fails
  for the wrong reason.
- Not testing with a connector that produces multiple chunks per document.
  Single-chunk documents hide change-detection bugs at the chunk level.

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Background: [DESIGN.md](../DESIGN.md) — source connectors, composition gates