hermes-muninndb-plugin 0.2.0

MuninnDB-backed memory provider plugin for Hermes Agent

MuninnDB memory provider for Hermes Agent

Bottom line:

• This is a standalone Hermes memory-provider plugin backed by MuninnDB.
• It uses MuninnDB's MCP endpoint for recall, explicit writes, and health/status checks.
• It adds deliberate memory tools plus automatic recall/capture hooks.

What it does

• Automatic recall before turns via muninn_recall
• Durable SQLite write-behind turn capture via muninn_remember
• Replays pending writes after crashes or restarts
• Mirrors built-in Hermes memory writes into MuninnDB
• Reuses the existing Muninn MCP server config from config.yaml when available, including its bearer token
• Exposes namespaced tools to the model:
  • muninndb_recall
  • muninndb_remember
  • muninndb_forget
  • muninndb_entity
  • muninndb_status
• Adds CLI helpers:
  • hermes muninndb status
  • hermes muninndb ping

Files

• __init__.py — Hermes plugin entrypoint wrapper
• cli.py — Hermes CLI wrapper
• src/hermes_muninndb_plugin/__init__.py — actual provider implementation
• src/hermes_muninndb_plugin/cli.py — actual CLI implementation
• plugin.yaml — Hermes plugin manifest
• pyproject.toml — packaging and test metadata
• .github/workflows/ci.yml — CI for tests/build
• tests/test_muninndb_plugin.py — unit tests

Installation

1. Put the plugin where Hermes can discover it.

Preferred layout when your Hermes version supports user-installed memory providers:

mkdir -p ~/.hermes/plugins/muninndb
rsync -a --delete /path/to/hermes-muninndb-plugin/ ~/.hermes/plugins/muninndb/

If your Hermes build still only scans bundled plugins/memory/ directories, symlink it into the Hermes source tree instead:

ln -s /path/to/hermes-muninndb-plugin ~/.hermes/hermes-agent/plugins/memory/muninndb

2. Configure Hermes to use the provider.

hermes config set memory.provider muninndb
hermes memory setup

3. Or write the config directly.

$HERMES_HOME/muninndb.json

{
  "endpoint": "http://127.0.0.1:8750/mcp",
  "vault": "default",
  "auto_recall": true,
  "auto_capture": true,
  "mirror_builtin_memory": true,
  "capture_assistant_turns": true,
  "recall_mode": "balanced",
  "recall_limit": 6,
  "recall_threshold": 0.45,
  "timeout": 10.0,
  "flush_timeout": 5.0,
  "max_turn_chars": 4000
}

Optional secret in $HERMES_HOME/.env:

MUNINN_MCP_TOKEN=your-token-here

You can also avoid duplicating the token entirely if Hermes already has a Muninn MCP server configured in config.yaml; the plugin will reuse that Authorization: Bearer ... header automatically.

You can also override config with env vars:

• MUNINN_MCP_URL
• MUNINN_ENDPOINT
• MUNINN_MCP_TOKEN
• MUNINN_VAULT

Behaviour mapping

Hermes lifecycle -> MuninnDB action

• prefetch(query) -> muninn_recall
• queue_prefetch(query) -> background muninn_recall
• sync_turn(user, assistant) -> background muninn_remember
• on_memory_write(add|replace, target, content) -> background muninn_remember
• on_session_end(messages) -> drain queued writes

Tool behaviour

muninndb_recall

• Purpose: deliberate recall when automatic injection is not enough
• Input: query, optional limit, mode, threshold
• Backend call: muninn_recall

muninndb_remember

• Purpose: explicit durable write
• Input: content, optional concept, type, summary, confidence, tags
• Backend call: muninn_remember

muninndb_forget

• Purpose: explicit cleanup/delete by memory id
• Input: id
• Backend call: muninn_forget

muninndb_entity

• Purpose: inspect an entity and its connected memories
• Input: name, optional limit
• Backend call: muninn_entity

muninndb_status

• Purpose: health/capacity snapshot
• Backend call: muninn_status

CLI

hermes muninndb status
hermes muninndb ping

Testing

make test
make smoke
make build

Equivalent direct commands:

python3 -m pytest tests/test_muninndb_plugin.py -q
python3 -m py_compile __init__.py cli.py src/hermes_muninndb_plugin/__init__.py src/hermes_muninndb_plugin/cli.py
python3 -m build

Design notes

• Uses stdlib HTTP (urllib) rather than third-party dependencies.
• Uses a durable SQLite async queue for write-behind persistence and crash recovery.
• Scopes recall and writes with platform, identity, session, and user tags.
• Falls back to the existing Hermes Muninn MCP server config in config.yaml so one source of truth can supply the token.
• For subagents/cron/flush contexts, write-back is disabled; recall still works.

Caveats

• Recall is semantic, so immediate exact-string lookups are not guaranteed to rank first without enough signal. Use muninndb_entity or Muninn's direct muninn_read/muninn_recall tools when you need forensic precision.
• This plugin talks to MuninnDB's MCP endpoint. If you prefer REST for some operations, that is a sensible follow-up, but MCP keeps the surface aligned with Muninn's richest toolset.
• The Hermes IDE plugin registry at hermes-hq/plugins is a different plugin system. Useful reference for packaging style, not the runtime contract used here.

Why this shape

• Minimal moving parts
• Good enough defaults
• No dependence on Muninn-specific Python SDKs that may shift underfoot
• Easy to inspect, patch, and extend without ritual sacrifice