Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add AtlasOmnia/hermes-custom-pack --skill hermes-mnemosynegit clone --depth 1 https://github.com/AtlasOmnia/hermes-custom-packWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/atlasomnia/hermes-custom-pack/hermes-mnemosyne)<a href="https://agentmods.dev/skills/atlasomnia/hermes-custom-pack/hermes-mnemosyne"><img src="https://agentmods.dev/badge/skills/atlasomnia/hermes-custom-pack/hermes-mnemosyne/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/atlasomnia/hermes-custom-pack/hermes-mnemosyne"><img src="https://agentmods.dev/badge/skills/atlasomnia/hermes-custom-pack/hermes-mnemosyne.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00030 | $0.03528 |
| Opus 5 | $0.00015 | $0.01764 |
| Sonnet 5 | $0.00006 | $0.00706 |
| Haiku 4.5 | $0.00003 | $0.00353 |
Grade A, and why
hermes-mnemosyne scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
100% identical to hermes-mnemosyne — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 244 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Hermes Mnemosyne Memory Provider
Mnemosyne is Hermes' primary local-first memory engine — SQLite with vector + FTS5 hybrid search, 19+ tools, auto-consolidation, and a standalone CLI. It's a pip-installed plugin (not a built-in toolset) discovered via $HERMES_HOME/plugins/mnemosyne/.
Quick Reference
When comparing memory stacks for the user, use references/memory-tool-selection-mem0-vs-mnemosyne.md: Mnemosyne is preferred for Hermes local-first profile memory; Mem0 is the safer productized choice for external/customer-facing apps.
For migrations from overlapping stacks such as LCM + built-in memory + gBrain, use references/memory-stack-migration-pilot.md. Prefer a staged simplification: preserve LCM, pilot Mnemosyne as the external memory provider, keep the incumbent system read-only for rollback, and retire redundant writers after measured acceptance.
| What | How |
|---|---|
| Check if active | hermes memory status or check memory.provider in config.yaml |
| Memory stats | mnemosyne stats (CLI) or mnemosyne_stats (tool) |
| Manual consolidation | mnemosyne sleep (current session) or mnemosyne sleep --all-sessions |
| Dry-run consolidation | mnemosyne sleep --all-sessions --dry-run |
| Enable auto-consolidation | Set memory.auto_sleep: true + memory.sleep_threshold: 50 in config.yaml |
| Use Hermes' model for compression | MNEMOSYNE_HOST_LLM_ENABLED=true in .env |
| Check if installed | hermes memory status; if the symlink is missing, run ~/.hermes/hermes-agent/venv/bin/mnemosyne-install |
Architecture
Mnemosyne is a memory provider, not a toolset. Its tools (mnemosyne_remember, mnemosyne_recall, mnemosyne_sleep, etc.) are injected through the memory manager — they are NOT accessible via enabled_toolsets. Do NOT use enabled_toolsets: ["mnemosyne"] in cron jobs or delegation configs.
Installation path and package split
Treat Mnemosyne as two moving parts:
mnemosyne-memory— core memory engine and optional embedding/local-LLM extras.mnemosyne-hermes— Hermes adapter/plugin package used by current upstream installation guidance.
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 11d ago First seen · 244 lines · 30 tokens per session scan A 9650e20e9560
hermes-mnemosyne is a skill published in the GitHub repository AtlasOmnia/hermes-custom-pack (56 stars, last pushed 27d ago), licensed MIT. It adds 30 tokens to every session and 3,528 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to hermes-mnemosyne, differing in 0 lines, and is treated as a copy.
Other skills, from other repositories
agent-dreaming-agnostic
Memory-agnostic background consolidation — reviews sessions, scores candidates, promotes durable insights to the active memory backend (built-in MEMORY.md or Holographic). Three-phase (Light/Deep/Condensation/REM). Run via cron or manually.
agent-dreaming
DEPRECATED — use agent-dreaming-agnostic instead. Background memory consolidation for built-in MEMORY.md only.
hermes-context-optimization
Use this when the user asks about Hermes prompt/context size, “hello” startup cost, compression behavior, memory/profile bloat, tool-schema overhead, skill loading, session-store/search-index storage, or multimodal/visual-context approaches such as Snapcompact.
hermes-mnemosyne
Mnemosyne is Hermes' primary local-first memory engine — SQLite with vector + FTS5 hybrid search, 19+ tools, auto-consolidation, and a standalone CLI. It's a pip-installed plugin (not a built-in toolset) discovered via $HERMESHOME/plugins/mnemosyne/.
hermes-session-maintenance
Use this skill when the user asks about pruning Hermes sessions, session retention, session DB size, hermes sessions prune, sessions.autoprune, sessions.retentiondays, session export/backup, or whether old conversations should be capped.
mnemosyne-maintenance
Use when: upgrading Mnemosyne, diagnosing slow/hung consolidation (mnemosynesleep), fixing missing embeddings, or troubleshooting import/version mismatches.