kmp-adapter-embedded
KMP is local-first agent memory that preserves what happened, when and why. This crate supplies its embedded storage adapters.
One EmbeddedKernelStore opens one data directory — a FORMAT_VERSION marker
next to store/ — and implements every persistence port the kernel needs:
graph reads over materialized adjacency, node detail, the append-only context
event log, projection runtime state, snapshots and quality telemetry. No
server, no cluster, no daemon.
One engine
The ports are written once against a small storage seam. Every new directory is SQLite and records format 2. No retired engine is linked.
| Engine | FORMAT_VERSION |
Store file | Availability |
|---|---|---|---|
| SQLite, WAL mode | 2 | store/kernel.sqlite3 |
active; always available |
Two agent hosts can open the same project memory, readers do not block the
writer, and a second writer waits for the commit lock. SQLite passes the full
conformance, kill -9 recovery and two-process no-lost-events suites. See
ADR-018. An unsupported store format is detected and rejected without touching
its bytes; preserve it, export with an explicitly archived compatible binary,
then import the portable bundle into an empty current store.
Quality telemetry uses its own WAL journal at telemetry/quality.sqlite3.
What durability means here
Canonical memory commits use SQLite synchronous=FULL in WAL, so the crash
contract is explicit: nothing is lost beyond the in-flight event, and replay
applies nothing twice. The bounded telemetry journal uses periodic FULL
durability and a final durable checkpoint.
Not a special case
The observable semantics are pinned by the conformance suite that also certifies the in-memory store and the Neo4j / Valkey adapters. A store that passes it behaves like the others or it does not ship.
License
Apache-2.0.