Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add Marcel-Bich/marcel-bich-claude-marketplace/plugin install credoWrote 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/marcel-bich/marcel-bich-claude-marketplace/rules)<a href="https://agentmods.dev/skills/marcel-bich/marcel-bich-claude-marketplace/rules"><img src="https://agentmods.dev/badge/skills/marcel-bich/marcel-bich-claude-marketplace/rules/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/marcel-bich/marcel-bich-claude-marketplace/rules"><img src="https://agentmods.dev/badge/skills/marcel-bich/marcel-bich-claude-marketplace/rules.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 | $0.00179 | $0.01506 |
| Opus 5 | $0.00089 | $0.00753 |
| Sonnet 5 | $0.00036 | $0.00301 |
| Haiku 4.5 | $0.00018 | $0.00151 |
Grade A, and why
rules scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 122 lines — stays where its author put it; the contents beside it link to each section on GitHub.
rules - per-repo credo special rules
A project can carry its own credo special rules in <target>/.credo/RULES.md: a
free-form Markdown file of project-local grants that widen credo's autonomy for that one
repo. Example: a debug-only repo declaring that restarting local services is always fine
without asking. These rules are credo-native and independent of dogma; they travel with the
repo (the file is versioned by default).
Resolve the file via the project layer (never cwd)
RULES.md lives in the RESOLVED target .credo/, not necessarily the cwd. Resolve it with
the shared project-layer resolver so it also works when you start from a launch hub:
"${CLAUDE_PLUGIN_ROOT}/scripts/credo-config.sh" rules
- Prints
<target>/.credo/RULES.mdplus(present)/(missing). - Exit 4 = no target resolved (cwd is a hub or has no credo project). Then the rules cannot
be located here - the user pins the target with
/credo:project <path>(or setsCREDO_DIR), and you retry. Do NOT fall back to reading a cwd-relative file.
When it prints a (present) path, Read that file. Resolution precedence is the same as for
config and items: CREDO_DIR env > session pin (/credo:project) > repo-root .credo/.
Config values live in the cascade, not the repo folder
All config and personal values (ntfy topic/server, sleep, identities, viewports) live in the
credo config cascade (builtin < global < profile < project). Resolve them ONLY via
credo-config.sh get <dotted.key> - never grep the plugin/repo folder, the template holds
empty placeholders. To send an ntfy push, use the helper
${CLAUDE_PLUGIN_ROOT}/scripts/credo-ntfy-send.sh "message" (it resolves the topic/server
through the cascade and is a silent no-op when ntfy is not configured).
Load and honor at session start
At the start of a session, resolve and (if present) Read .credo/RULES.md, then honor its
grants for the whole session. A grant relaxes what you would otherwise ask about or avoid -
apply it as if the user had stated it directly, because they did (in that repo). If the file
is missing, there simply are no special rules; carry on with credo defaults.
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 · 122 lines · 179 tokens per session scan A 5a7311065345
rules is a skill published in the GitHub repository Marcel-Bich/marcel-bich-claude-marketplace (13 stars, last pushed yesterday), licensed MIT. It adds 179 tokens to every session and 1,506 once invoked, about $0.0009 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.
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