arc-sync

arc-sync is a skill for Claude Code, Codex from comma-compliance/arc-relay. It costs 83 tokens per session (1,110 once invoked), scanned A, original, MIT.

A skill for managing MCP servers, which are external services that give an AI coding tool additional capabilities, through Arc Relay.

In plain words
What is it for?
Use it when setting up MCP servers, checking their status, fixing missing tools, or configuring integrations for a project.
Why use it?
It provides one place to add, remove, list, sync, configure, and troubleshoot those services without editing configuration files by hand.

Skill for Claude CodeCodex

Written for Claude Code and Codex: allowed-tools in frontmatter, but also reads ~/.codex or $CODEX_HOME. Also seen: mentions CLAUDE.md; mentions Claude Code; mentions AGENTS.md.

Good fit Use it when setting up MCP servers, checking their status, fixing missing tools, or configuring integrations for a project.

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Install with agentmods
npx agentmods add skills/comma-compliance/arc-relay/arc-sync
Install

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.

Any agent
npx skills add comma-compliance/arc-relay --skill arc-sync
Clone the repo
git clone --depth 1 https://github.com/comma-compliance/arc-relay

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for arc-sync

README.md
[![agentmods](https://agentmods.dev/badge/skills/comma-compliance/arc-relay/arc-sync.svg)](https://agentmods.dev/skills/comma-compliance/arc-relay/arc-sync)
Your own site
<a href="https://agentmods.dev/skills/comma-compliance/arc-relay/arc-sync"><img src="https://agentmods.dev/badge/skills/comma-compliance/arc-relay/arc-sync.svg" alt="Measured on agentmods" height="20"></a>
Per session 83 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,110 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00083 $0.01110
Opus 5 $0.00042 $0.00555
Sonnet 5 $0.00017 $0.00222
Haiku 4.5 $0.00008 $0.00111

Measured 7d ago against content hash 286c69beb8fb, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

arc-sync 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 7d 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.

skills/arc-sync/SKILL.md · 89 lines

How it starts

The opening of the file, as written. The whole thing — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MCP Server Management via arc-sync

MCP servers in this environment are managed by Arc Relay. Never edit .mcp.json or .codex/config.toml directly - use arc-sync commands.

First-run check

Before running any arc-sync command, check if arc-sync is configured:

  1. Run arc-sync status --json 2>/dev/null. If it fails or returns {"error": ...}:

    • Check if arc-sync binary exists: which arc-sync
    • If not installed: tell the user to ask their admin for an install command (invite token), or run arc-sync init if they have credentials
    • If installed but not configured: run arc-sync init to set up
  2. If status succeeds but shows missing Claude integration, suggest:

    • arc-sync setup-claude for personal skill installation
    • arc-sync setup-codex for personal Codex CLI instructions
    • arc-sync setup-project for team-shared project instructions

Current project status

!arc-sync status --json 2>/dev/null || echo '{"error": "arc-sync not installed or not configured - run: arc-sync init"}'

Commands

Command Description
arc-sync Interactive sync - add new relay servers to project
arc-sync list Show all servers (use --json for machine-readable)
arc-sync add <name> Add a specific server to this project
arc-sync remove <name> Remove a server from this project
arc-sync reset Clear the skip list for this project
arc-sync status Show config and project details
arc-sync setup-claude Install Claude Code skill and CLAUDE.md instructions
arc-sync setup-codex Install Codex CLI AGENTS.md instructions
arc-sync setup-project Add MCP instructions to project .claude/CLAUDE.md and AGENTS.md
arc-sync server add <name> --type remote <url> Register a remote MCP server on the relay
arc-sync server add <name> --type stdio --build python --package <pkg> Register an auto-build server
arc-sync server add <name> --type stdio --image <img> Register a Docker stdio server
arc-sync server add <name> --type http --image <img> --port <p> Register a Docker HTTP server
arc-sync server remove <name> Delete a server from the relay
arc-sync server start <name> Start a relay server
arc-sync server stop <name> Stop a relay server

Read the full file on GitHub · 89 lines

Changes

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.

  1. 7d ago First seen · 89 lines · 83 tokens per session scan A 286c69beb8fb

Subscribe to this mod's changes

arc-sync is a skill published in the GitHub repository comma-compliance/arc-relay (57 stars, last pushed 3d ago), licensed MIT. It adds 83 tokens to every session and 1,110 once invoked, about $0.0004 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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