ShineMnemos vs Cognee: ontology validation vs truth gates. An honest side-by-side.
Cognee and ShineMnemos start from the same premises: memory for agents should be a graph, it should run self-hosted, and it should be reachable over MCP. Cognee (~30k GitHub stars, Apache-2.0) builds that on an ECL pipeline — extract, cognify, load — that ingests documents and other sources and turns them into a queryable knowledge graph. ShineMnemos (Apache-2.0, 316 tests, 11 plugins) does it as a single SQLite file with an in-process node graph and an MCP server. On architecture we are neighbours, not opponents.
The real divergence is what gets validated at write time, and this is worth stating precisely because the two things sound alike. Cognee's `ontology_valid` flag checks whether a fact conforms to the declared schema — the right entity types, the right relation, the right shape. That is genuinely useful: it keeps the graph structurally coherent and makes traversal predictable. But schema conformance says nothing about whether the statement is true. `(ServiceX, deployed_at, 2019-01-01)` can be perfectly ontology-valid and completely wrong.
ShineMnemos validates content. Each fact passes five gates — freshness, source, numbers, consistency, reproducibility — followed by a truth-gate that returns a verdict (up to 6/6) and a confidence score. Facts get a TTL and are auto-invalidated once stale, so the graph degrades on a schedule instead of silently aging. Form validation and truth validation are complementary, not substitutes; we simply chose the harder one to build.
| ShineMnemos | Cognee | |
|---|---|---|
| Storage | One SQLite file, in-process node graph | Self-hosted graph store |
| Interface | MCP server | MCP server |
| Write-time validation | 5 gates + truth-gate verdict (up to 6/6) + confidence | `ontology_valid` — schema conformance |
| What is checked | Content: is this claim supported and consistent? | Form: does this fit the declared ontology? |
| Ingestion | Facts written by the agent through the gates | ECL pipeline over documents and mixed sources |
| Staleness | TTL, confidence, auto-invalidation | Application-level |
| Locality | Fully local — data never leaves the machine | Self-hosted |
| Exact lookup | ~0.001 ms in-process (~10k nodes, no network) | Depends on backing store |
| License / maturity | Apache-2.0, 316 tests, 11 plugins | Apache-2.0, ~30k stars |
Use Cognee for building a structured knowledge graph out of existing corpora, when ontology enforcement matters and you want a project with real production mileage.
Use ShineMnemos when the question is not "is this well-formed?" but "is the agent allowed to assert this?" — verified facts, confidence and TTL attached, in one local file with nothing leaving the machine.
They compose: Cognee for building the graph, ShineMnemos for the facts your agent states as true.
Try ShineMnemos → — Apache-2.0, one SQLite file, MCP server, pay-per-call in USDC. No signup.