Since KIDLISP_DATOMIC=on is enabled on lith, new pieces get stored by store-kidlisp via the Datomic sidecar (store-kidlisp-datomic.mjs), not in MongoDB's `kidlisp` collection. Any Mongo-only read path then reports "Piece '$code' not found" when the user tries to keep/rebake/sync a freshly-created piece. Reported against $r94 today (seen in the DB as present via /api/store-kidlisp?code=r94, absent when queried directly in Mongo). Adds backend/kidlisp-read.mjs :: loadKidlispPiece(database, code): - Reads from the sidecar when the feature flag is on. - Overlays the Mongo row on top so rebake-era fields (ipfsMedia, mediaHistory, kept, tezos, pendingRebake) keep working for pieces already kept under the legacy flow. - Falls back to a direct Mongo read when Datomic is off or the sidecar call fails. Wires the helper into every keep-flow entrypoint that previously read Mongo directly: - keep-prepare.mjs (initial validate) - keep-prepare-background.mjs (bake pipeline) - keep-confirm.mjs (mint confirm) - keep-update.mjs (on-chain metadata sync) - keep-update-confirm.mjs (sync confirm) Also marks the Mongo updateOne calls in keep-prepare-background, keep-confirm, and keep-update-confirm as { upsert: true } so the first bake/mint/sync of a Datomic-only piece creates a Mongo row to receive ipfsMedia / kept / tezos fields, instead of silently no-op'ing because no matching document exists. Leaves kidlisp-keep.mjs alone — it queries the unrelated `kidlisp-codes` legacy collection. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>