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 kevin-hs-sohn/hipocampus --skill searchgit clone --depth 1 https://github.com/kevin-hs-sohn/hipocampusWrote 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/kevin-hs-sohn/hipocampus/search)<a href="https://agentmods.dev/skills/kevin-hs-sohn/hipocampus/search"><img src="https://agentmods.dev/badge/skills/kevin-hs-sohn/hipocampus/search/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/kevin-hs-sohn/hipocampus/search"><img src="https://agentmods.dev/badge/skills/kevin-hs-sohn/hipocampus/search.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00044 | $0.00930 |
| Opus 5 | $0.00022 | $0.00465 |
| Sonnet 5 | $0.00009 | $0.00186 |
| Haiku 4.5 | $0.00004 | $0.00093 |
Grade A, and why
hipocampus-search 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 13d 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.
How it starts
The opening of the file, as written. The whole thing — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Hipocampus Search
Quick Reference
| Action | Command |
|---|---|
| Hybrid search (best quality) | qmd query "keyword1 keyword2" |
| Keyword search (fast) | qmd search "keyword1 keyword2" |
| Vector search only | qmd vsearch "semantic query" |
| Find files | qmd search "query" --files |
| Read file | qmd get "path/to/file.md" |
| Re-index | qmd update |
Which Search to Use
Check hipocampus.config.json:
search.vector: true(default) →qmd queryfor best results (BM25 + vector + rerank)search.vector: false→qmd searchfor BM25 keyword search
ROOT.md — "Do I Know About This?"
memory/ROOT.md is a functional index of everything in memory, auto-loaded every session. It has four sections:
- Active Context — current week's work and priorities (immediate situational awareness)
- Recent Patterns — cross-cutting insights not tied to a specific time period
- Historical Summary — high-level chronology of past periods
- Topics Index — keyword lookup table for O(1) "do I know about X?" judgment
Before any lookup, check ROOT.md first:
- Topic found in Topics Index → search memory (qmd or tree traversal)
- Topic NOT in Topics Index → use external search or answer from general knowledge
- This eliminates "loading to decide whether to load" — ROOT.md is always in context
This is the core value of the compaction tree. Search only works when you know what to search for. The Topics Index tells you what you know at a glance.
BM25 Query Construction
When using qmd search (BM25 mode), queries must be keywords, not natural language.
Rules
- Use 2-4 specific keywords — more precise = better results
- No natural language — strip filler words
- Try variations — if first query misses, use synonyms or related terms
Examples
| Bad (natural language) | Good (keywords) |
|---|---|
| "How do I configure the database?" | "database config" |
| "What did we decide about caching?" | "caching decision" |
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.
- 13d ago First seen · 98 lines · 44 tokens per session scan A 8fafde928a79
hipocampus-search is a skill published in the GitHub repository kevin-hs-sohn/hipocampus (206 stars, last pushed 3mo ago), licensed MIT. It adds 44 tokens to every session and 930 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
mnemo-cortex
Installs and wires Mnemo Cortex (local-first persistent memory) into OpenClaw and other MCP-capable agents. Use for cross-session recall, decision history, or multi-agent shared memory.
capture-knowledge
A guide for saving useful, reusable knowledge from conversations and documents into a structured personal knowledge base. It separates original source material from concise pages about individual concepts.
second-brain-attach
A setup process for connecting a new or reset AI agent to a local Second Brain—a personal collection of rules, identity information, and reusable skills. It installs the required skills, connects the supporting service, and checks the setup in a fresh session.
second-brain-distill
A skill for extracting reusable knowledge from selected historical AI-agent conversations and archiving the results. It can process conversations only within a clearly defined, authorized batch.
second-brain-doctor
A read-only health check for an agent’s connection to a local Second Brain. It checks the authoritative files, installed skills, supporting service, access rules, version drift, and behavior in a new session.
second-brain-learn
A learning tool that reviews the current conversation and work evidence to find durable preferences, project rules, reusable methods, and lessons. It routes each finding to the appropriate long-term owner or leaves it unsaved when it has no lasting value.