Close the last contract gaps openhuman#5560 needs to drop the engine crate

[YellowSnnowmann]

Final upstream piece for openhuman#5560. With this released and pinned, the host can remove tinymemory-core and tinymemory-tinycortex from its [dependencies] in one pass.

The gap is measured, not estimated

Deleting both crates from the host's manifest and compiling the product profile gives 89 errors across 31 distinct symbols. That set is the whole remaining ask — closing all of it in one release is deliberate, because a gap left open costs another merge-release-repin cycle.

It splits in two: types the host reaches only through pub use shims, and behaviour with no member at all. I checked the second half against every member of all thirteen families at HEAD — 140 members, zero hits.

Two new families

MemorySync — run_connection_sync, source_sync_state, sync_audit_log, estimate_sync_cost_usd, sync_statuses, raw_archive_coverage, rebuild_from_raw_archive.

run_connection_sync is worth a note: #100 moved the periodic loops into the module, but the host's five call sites are manual "sync now" paths. A user pressing a button is still the host's to trigger, so the on-demand half needs a door.

MemorySessions — coding_session_status, ingest_coding_sessions.

MemoryMaintenance::diagnose answers a structured Diagnosis, replacing the host's reach for the engine's async_run_doctor. It is a separate member from doctor rather than a widening of it, because the two return different things.

Why estimate_sync_cost_usd is a member

It is pure arithmetic and the host could do it — but the same constants back SyncAuditEntry's own cost field. A host-side copy becomes a second price that drifts from the one the audit rows were actually written with, so the cost stays computed where those rows are.

The types, moved rather than copied

~20 types — source descriptors, the composio provider vocabulary, tree scoring and summarising, retrieval types, diff ops, a facet class — move to tinymemory-bus, with the engine re-exporting from there so there is exactly one definition. Copying them would create the drifting-duplicate problem where a field added on one side is a decode failure on the other with nothing to catch it.

Two carve-outs:

• SyncState moves; load/save do not. They do I/O, and the contract crate stays free of storage engines, HTTP clients and async runtimes. They become the PersistedSyncState extension trait in the engine, beside the SyncStateStore seam that was already there.
• apply_kind_defaults moves to tinymemory-sources so a host can fill a new entry's caps without linking the engine. Its defaults are what the retroactive Composio caps migration applies, so a change here changes what already-registered sources reconcile against — the tests say so out loud.

Additive throughout

Every new trait member defaults to Unsupported, so no existing driver stops compiling; every new field is #[serde(default)]. The host and module are separately compiled and released, so an older peer decodes a newer payload rather than failing to load.

All new bus methods are registered in the four places that must agree — interface impl, module manifest, tinymemory_bus::METHODS (plus its length and the doc count), and EXPECTED_METHODS — in declaration order, because the drift assertion compares sequences rather than sets.

Validation

cargo check --workspace --all-targets clean in both workspaces. cargo test --workspace 2034 passing. cargo clippy --all-targets --all-features -D warnings clean on the root and the module workspace, cargo fmt clean on both, and engine-containment.sh holds. Module lane: 69 unit tests and every isolated loader case, which is what proves the four-place registration agrees.

[coderabbitai]

Important

• 🔍 Trigger review

This repository does not receive automatic reviews because it has fewer than 10 stars.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 52df578e-5812-4dec-a450-b3b41be9bdac

Warning

Your free Security trial is over. An organization admin can activate billing to continue.

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[tinysweeper]

tinysweeper found nothing blocking. Approving.

$0.0000 · 0 in / 0 out