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 agentmods add instructions/sturlese/hippocampus/agents-mdgit clone --depth 1 https://github.com/sturlese/hippocampusWhat 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 | $0.00054 | $0.00054 |
| Opus 5 | $0.00027 | $0.00027 |
| Sonnet 5 | $0.00011 | $0.00011 |
| Haiku 4.5 | $0.00005 | $0.00005 |
Grade A, and why
hippocampus AGENTS.md 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 yesterday.
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.
What it actually says
Codex project instructions
Read and follow CLAUDE.md in the repository root completely before doing any
work. It is the canonical project contract, written for Claude Code as the
native host; its vault rules and workflows apply unchanged to Codex.
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.
- yesterday First seen · 6 lines · 54 tokens per session scan A 906654859568
hippocampus AGENTS.md is an instructions file published in the GitHub repository sturlese/hippocampus (26 stars, last pushed 10d ago), licensed MIT. It adds 54 tokens to every session, about $0.0003 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 instructions, from other repositories
siyuan AGENTS.md
AGENTS.md instructions for siyuan-note/siyuan, covering agents.md, 1. non-negotiable constraints, do not hand-edit, verification and prohibited operations and 2. project-specific rules.
obsidian-mcp-server AGENTS.md
Instructions for cyanheads/obsidian-mcp-server, covering agent protocol, what's next?, core rules, patterns and tool — obsidianlisttags.
llm-wiki-compiler AGENTS.md
Instructions for atomicstrata/llm-wiki-compiler, covering llmwiki, development guidelines, code style & standards, clean code rules and comments and documentation.
pi-llm-wiki AGENTS.md
Instructions for zosmaai/pi-llm-wiki, covering agents.md, project, tech stack, file layout and conventions.
commonplace CLAUDE.md
Instructions for briannaworkman/commonplace: This repository holds two vaults. Nothing should be ingested or edited here at the root.
Hatchdoor AGENTS.md
AGENTS.md instructions for BatterWorks/Hatchdoor, covering agent instructions, local-only instructions, running dev servers, dev vault fixtures and codegraph.