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/systempromptio/systemprompt-core/claude-mdgit clone --depth 1 https://github.com/systempromptio/systemprompt-coreWrote 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/instructions/systempromptio/systemprompt-core/claude-md)<a href="https://agentmods.dev/instructions/systempromptio/systemprompt-core/claude-md"><img src="https://agentmods.dev/badge/instructions/systempromptio/systemprompt-core/claude-md.svg" alt="Measured on agentmods" 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 | $0.03009 | $0.03009 |
| Opus 5 | $0.01504 | $0.01504 |
| Sonnet 5 | $0.00602 | $0.00602 |
| Haiku 4.5 | $0.00301 | $0.00301 |
Grade A, and why
systemprompt-core CLAUDE.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 5d 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.
The source is not reproduced here
A licence we could not identify
The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.
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.
- 5d ago First seen · 153 lines · 3,009 tokens per session scan A 32e7d927c27d
systemprompt-core CLAUDE.md is an instructions file published in the GitHub repository systempromptio/systemprompt-core (8 stars, last pushed yesterday), with no licence file. It adds 3,009 tokens to every session, about $0.0150 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 2026-08-31.
Other instructions, from other repositories
openhuman AGENTS.md
AGENTS.md instructions for tinyhumansai/openhuman, covering openhuman, repository layout, runtime scope, ios client (experimental, non-shipping) and commands (from repo root).
openhuman CLAUDE.md
Claude Code instructions for tinyhumansai/openhuman, a project described as: OpenHuman is an open source personal AI for Mac, Windows and Linux — local-first memory, agent orchestration, and deep research.
playbooks CLAUDE.md
Instructions for playbooks-ai/playbooks, covering claude.md, project overview, core architecture, framework components and key architectural insights.
Herdforge CLAUDE.md
Claude Code instructions for Kampe/Herdforge, covering claude.md - build bootstrap & routing protocol, 1. quick invariants (hard rules), 2. fast commands, build binary and run preflight, unit tests, and build.
co-evolution CLAUDE.md
Instructions for alanshurafa/co-evolution, covering co-evolution - cross-ai document refinement, default rule, components, co-evolution skill (skills/co-evolution/) and co-evolve bouncer (co-evolve-bouncer.sh).
orcho-mcp AGENTS.md
Instructions for symphos-ai/orcho-mcp, covering orcho-mcp instructions, scope, local instruction files, workspace development pipeline and stable install is read-only.