Severian memory plugin (for Hermes Agent)

Drop-in memory provider for Hermes. Install from the plugin catalog:

hermes plugins install severian

Or from a checkout: copy this folder to $HERMES_HOME/plugins/severian/ and run hermes pm repair, which installs the pinned severian package from PyPI into Hermes' managed environment.

Then set memory: provider: severian in config.yaml and restart Hermes.

See the repo root README for features, benchmark results and configuration.

Disclosures

• Memory is local. Everything is stored on the machine: by default under the Hermes data root (<HERMES_HOME>/severian/, SQLite), or in the PostgreSQL database you point SEVERIAN_DSN at. The engine makes no third-party calls.
• Recall injects context. The provider's purpose is returning saved memories and assembled context blocks into agent turns. Nothing is sent anywhere beyond what the bullets below name.
• Optional network paths, each one you switch on:
  • SEVERIAN_EMBEDDING=qwen: downloads the Qwen3-Embedding-0.6B weights from huggingface.co on first use.
  • SEVERIAN_EMBEDDING=remote-qwen: talks to your own sidecar socket (SEVERIAN_EMBED_SOCKET), no internet.
  • SEVERIAN_USER_FACTS=1: sends conversation turns to the model backend Hermes is already configured with, in the background worker you run, to short facts.
  • SEVERIAN_RERANK: loads a cross-encoder locally (weights download from huggingface.co on first use).
  • severian serve: starts the HTTP API yourself; not started by the plugin.
• Background worker is yours. The plugin never spawns hidden processes; the derivation worker runs when you or your cron run severian work.
• No telemetry, no self-updating, no credential files. Configuration is the SEVERIAN_* environment variables you set. The one secret, SEVERIAN_DSN (optional; it can hold a database password), is read through Hermes's profile-aware secret scope (agent.secret_scope.get_secret), never from config files the plugin reads.
• No process-wide changes. The optional embedding loaders pass offline mode to the model loader rather than setting environment variables for the Hermes process.