Borrowing it
Nothing to install: this file belongs to lagz0ne/c3-skill. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/lagz0ne/c3-skill/main/AGENTS.mdgit clone --depth 1 https://github.com/lagz0ne/c3-skillWrote 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/lagz0ne/c3-skill/agents-md)<a href="https://agentmods.dev/instructions/lagz0ne/c3-skill/agents-md"><img src="https://agentmods.dev/badge/instructions/lagz0ne/c3-skill/agents-md/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/instructions/lagz0ne/c3-skill/agents-md"><img src="https://agentmods.dev/badge/instructions/lagz0ne/c3-skill/agents-md.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 | $0.00593 | $0.00593 |
| Opus 5.5 | $0.00237 | $0.00237 |
| Sonnet 5.5 | $0.00119 | $0.00119 |
| Haiku 4.5 | $0.00059 | $0.00059 |
Grade A, and why
c3-skill 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 2mo 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 — 46 lines — stays where its author put it; the contents beside it link to each section on GitHub.
C3 Design Agent Instructions
Local C3 Source Rule
This repository is the C3 project source. All C3 operations here must use this checkout, not an installed/global C3 skill.
Hard rules:
- Do not use bare
c3x; it may resolve to a global installed skill. - Do not load C3 from
~/.agents/skills/c3,~/.claude/skills/c3,~/.codex/skills/c3, or marketplace installs for this repo. - Load C3 skill instructions from
skills/c3/SKILL.mdin this repository. - Run C3 through the local built wrapper:
C3X_MODE=agent bash skills/c3/bin/c3x.sh <command>
If the local wrapper or binary is missing, build it first:
bash scripts/build.sh
Then create a session-local alias/function and use it for every C3 command:
alias c3local='C3X_MODE=agent bash skills/c3/bin/c3x.sh'
c3local check
If command behavior, output format, or verification result seems inconsistent with this source tree, be doubtful. First prove which binary and skill path are being used, then continue.
Workflow
- Use RED-GREEN-TDD for changes.
- Keep
.c3/c3.dbtreated as disposable local cache, not submitted truth. - Verify with
c3local checkand the relevant project tests before done. - For code changes in
cli/, rungo test ./...fromcli/.
CLI Flow Principles
- CLI commands should lead within their capabilities: inspect what they can prove, return the smallest useful answer, and include the next repair step when there is a failure.
- In
C3X_MODE=agent, structured command output must be TOON, not JSON. Do not add command-localjson.NewEncoderpaths for agent-facing command results; route through the shared output helpers. - Failure output is part of the workflow contract. Prefer grouped blockers and direct fix loops over one-error-at-a-time guessing, but keep operations tight enough that the command cannot leave canonical
.c3/files in an impossible partial state. - Broken canonical
.c3/state should block read-only commands, but repair mutations must still run. Usewrite --section,set --section, oradd adrfor focused repair, then finish withc3local check --include-adr. - For migration failures, follow the CLI's printed fix loop exactly.
BLOCKED: N component(s)means no migration writes occurred; usec3local migrate repair-plan, repair listed sections withc3local migrate repair <id> --section <name>, runc3local cache clear, import, continue migration, then check/verify.
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.
- 2mo ago First seen · 46 lines · 593 tokens per session scan A 1193210c2773
c3-skill AGENTS.md is an instructions file published in the GitHub repository lagz0ne/c3-skill (12 stars, last pushed 3mo ago), licensed MIT. It adds 593 tokens to every session, about $0.0024 per session on Opus 5.5. 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
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
deno copilot-instructions.md
Copilot instructions for denoland/deno, covering deno development guide for github copilot, network access, high level overview, key directories and key files to understand first.