Single-Host Node

2 min readEngineerReference architecture

What this page covers

A single Stigmem node is a self-contained FastAPI process backed by SQLite (or libSQL/Postgres). This diagram shows the internal component layout and request flow.

Audience: engineers deploying or contributing to the Stigmem reference node.

Key components

Component

File

Responsibility

FastAPI Router

main.py, routes/

HTTP endpoint registration, lifespan management.

Auth Middleware

auth.py

Resolves Authorization: Bearer to an identity with scopes and permissions.

Source Attestation

auth.py

Validates source URI against caller's entity_uri (Spec-X6).

HLC Clock

hlc.py

Thread-safe hybrid logical clock; advances on local writes and federated receives.

Fact Ingest

routes/facts.py

Idempotent fact insertion, CID computation, scope enforcement.

Conflict Detector

routes/facts.py

Detects (entity, relation, scope) value divergence; creates contradiction records.

Decay Sweeper

decay.py

Background task that expires facts past valid_until or low confidence.

Federation Pull

federation_pull.py

Periodically fetches new facts from registered peers using HLC cursor.

Storage

db.py

SQLite/libSQL/Postgres with migration support; vec_facts and entity_edges for recall.

Key components​

Key components