What is reearth-cms-mcp AGENTS.md?

Repository guidance for re:earth-cms-mcp, a Go MCP server that connects an AI agent to the Re:Earth content-management system.

Building the server and reading, creating, deleting, or commenting on Re:Earth content items and assets.

It documents the project layout, required environment settings, build commands, and available operations so agents can work against the correct CMS workspace.

How reearth/reearth-cms-mcp configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to reearth/reearth-cms-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/reearth/reearth-cms-mcp/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/reearth/reearth-cms-mcp

Made for: Codex, OpenCode.

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/reearth/reearth-cms-mcp/agents-md/github.svg)](https://agentmods.dev/instructions/reearth/reearth-cms-mcp/agents-md)

Your own site

<a href="https://agentmods.dev/instructions/reearth/reearth-cms-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/reearth/reearth-cms-mcp/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/reearth/reearth-cms-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/reearth/reearth-cms-mcp/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 796 This file is loaded in full into every session.

When invoked 796 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00796	$0.00796
Opus 5.5	$0.00318	$0.00318
Sonnet 5.5	$0.00159	$0.00159
Haiku 4.5	$0.00080	$0.00080

Measured 10d ago against content hash 4188fc03e646, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

reearth-cms-mcp 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 10d 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.

AGENTS.md · 101 lines

How it starts

The opening of the file, as written. The whole thing — 101 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Re:Earth CMS MCP Server

A Model Context Protocol (MCP) server for Re:Earth CMS API, built with Go.

Project Structure

.
├── main.go                      # Entry point, tool registration
├── internal                     # Internal application code
├── .github/workflows/           # GitHub Actions workflows
└── .goreleaser.yaml             # GoReleaser configuration

How to Build

Requirements

Go 1.27+

Build

go build .

Build with Version

go build -ldflags "-X github.com/reearth/reearth-cms-mcp/internal/version.Version=v1.0.0" .

How to Run

Environment Variables

Variable	Required	Description
`REEARTH_CMS_TOKEN`	Yes	API token for authentication
`REEARTH_CMS_WORKSPACE_ID`	Yes	Workspace ID to operate on
`REEARTH_CMS_BASE_URL`	No	Base URL (default: `https://api.cms.reearth.io/api`)

Available Tools

Tool	Description
`comment_to_asset`	Add a comment to an asset
`comment_to_item`	Add a comment to an item
`create_item`	Create a new item
`delete_item`	Delete an item
`get_asset`	Get a specific asset by ID
`get_item`	Get a specific item by ID
`get_model`	Get a specific model by ID
`list_items`	List items in a model
`list_models`	List all models in a project
`update_item`	Update an existing item

Best Practices Summary

Development Guidelines

Write idiomatic Go code following standard conventions and patterns
Use interface-driven development with explicit dependency injection
Prefer composition over inheritance with small, purpose-specific interfaces
Write short, focused functions with single responsibility
Handle errors explicitly using wrapped errors for traceability
Avoid global state and use constructor functions for dependency injection
Sort functions, methods, tools and types alphabetically for easier navigation

Read the full file on GitHub · 101 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.

10d ago Changed 4188fc03e646
2mo ago First seen · 101 lines · 796 tokens per session scan A c17633dd833f

Subscribe to this mod's changes

reearth-cms-mcp AGENTS.md is an instructions file published in the GitHub repository reearth/reearth-cms-mcp (2 stars, last pushed 10d ago), licensed Apache-2.0. It adds 796 tokens to every session, about $0.0032 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 2026-08-31.

Go cms mcp mcp-server reearth

reearth-cms-mcp AGENTS.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
reearth-cms-mcp AGENTS.mdreearth/reearth-cms-mcp	Instructions file	2	10d ago	Apache-2.0	A	796	Codex, OpenCode
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

reearth-cms-mcp: Instructions file for Codex