dmarcguard: Instructions file for Claude Code

CLAUDE.md

dmarcguard CLAUDE.md is an instructions file for Claude Code from dmarcguardhq/dmarcguard. It costs 4,090 tokens per session, scanned A, original, Apache-2.0.

A project guide for Parse DMARC, a Go application that reads DMARC email reports and shows them in a web dashboard. DMARC is an email-security standard that helps verify whether messages claiming to come from a domain are legitimate.

In plain words
What is it for?
Use it when installing dependencies, changing the Go backend or Vue dashboard, running the application, or working with its database and MCP integration.
Why use it?
It gives a coding agent the project’s structure, technologies, setup details, and development commands in one place.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md.

This is dmarcguardhq/dmarcguard's own configuration. It tells Claude Code how to work on dmarcguard itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything dmarcguard configures →

Reuse

Borrowing it

Nothing to install: this file belongs to dmarcguardhq/dmarcguard. 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/dmarcguardhq/dmarcguard/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/dmarcguardhq/dmarcguard

Made for: Claude Code.

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Per session 4,090 This file is loaded in full into every session.
When invoked 4,090 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.04090 $0.04090
Opus 5 $0.02045 $0.02045
Sonnet 5 $0.00818 $0.00818
Haiku 4.5 $0.00409 $0.00409

Measured 2d ago against content hash 0af188929afb, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

dmarcguard 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 2d 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.

CLAUDE.md · 428 lines

How it starts

The opening of the file, as written. The whole thing — 428 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Parse DMARC - Project Guide

A Go application that fetches DMARC reports from IMAP mailboxes, parses them, and displays them in a Vue.js dashboard. Also supports MCP (Model Context Protocol) for AI assistant integration.

Tech Stack

  • Backend: Go 1.25.4 (see go.mod for exact version)
  • Frontend: Vue.js 3 with Vite
  • Database: SQLite (supports both CGO and pure-Go variants)
  • Package Manager: Bun (for frontend)
  • Task Runner: Just (Justfile)
  • CLI Framework: urfave/cli/v3
  • JSON Library: goccy/go-json (high-performance)
  • Logging: rs/zerolog (structured logging)
  • Metrics: Prometheus client_golang
  • MCP SDK: modelcontextprotocol/go-sdk

Project Structure

parse-dmarc/
├── main.go                    # Main application entry point
├── internal/
│   ├── api/                   # REST API server and embedded frontend
│   │   └── server.go          # HTTP server, routes, metrics middleware
│   ├── config/                # Configuration management (JSON + env vars)
│   │   └── config.go          # Config loading and validation
│   ├── imap/                  # IMAP client for fetching emails
│   │   └── client.go          # Email fetching logic
│   ├── logger/                # Structured logging setup
│   │   └── logger.go          # Zerolog configuration
│   ├── mcp/                   # MCP (Model Context Protocol) server
│   │   ├── server.go          # MCP server (stdio and HTTP/SSE)
│   │   ├── tools.go           # MCP tool implementations
│   │   └── oauth/             # OAuth2 authentication for MCP
│   │       ├── config.go      # OAuth configuration
│   │       ├── middleware.go  # Bearer auth middleware
│   │       ├── metadata.go    # RFC 9728 metadata endpoint
│   │       └── verifier.go    # Token verification
│   ├── metrics/               # Prometheus metrics
│   │   └── metrics.go         # Metrics definitions and HTTP middleware
│   ├── parser/                # DMARC XML parser
│   │   ├── dmarc.go           # Parsing logic
│   │   └── dmarc_test.go      # Parser tests
│   └── storage/               # SQLite database layer
│       ├── common.go          # Shared SQL queries and types
│       ├── sqlite_cgo.go      # CGO SQLite (mattn/go-sqlite3)
│       └── sqlite_no_cgo.go   # Pure Go SQLite (modernc.org/sqlite)
├── src/                       # Vue.js 3 frontend source
│   ├── App.vue                # Main application component
│   ├── main.js                # Vue entry point
│   ├── assets/
│   │   └── base.css           # Base styles
│   ├── stores/                # Pinia-like state management
│   │   ├── index.js           # Store exports
│   │   ├── theme.js           # Theme (dark/light/system) store
│   │   └── settings.js        # API endpoint settings store
│   └── components/
│       ├── dashboard/
│       │   ├── DashboardHero.vue   # Dashboard header/hero section
│       │   ├── RecentReports.vue   # Recent reports list
│       │   └── ReportDrawer.vue    # Report detail drawer
│       ├── settings/
│       │   └── SettingsModal.vue   # Settings modal (theme, API endpoint)
│       └── tools/
│           └── DnsGenerator.vue    # DMARC DNS record generator
├── public/                    # Static frontend assets (favicons, logos)
├── assets/                    # Project assets (screenshots, images)
├── deploy/                    # Deployment configurations
│   ├── coolify.yaml           # Coolify deployment
│   ├── captain-definition     # CapRover deployment
│   ├── digitalocean/          # DigitalOcean Droplet/Marketplace
│   │   ├── packer.pkr.hcl     # Packer image build
│   │   ├── marketplace.yaml   # DO Marketplace metadata
│   │   └── scripts/           # Setup scripts
│   └── dokploy/               # Dokploy deployment
│       ├── template.toml
│       └── docker-compose.yml
├── grafana/                   # Grafana monitoring
│   ├── dashboard.json         # Pre-built dashboard
│   └── provisioning.yaml      # Auto-provisioning config
├── scripts/                   # Utility scripts
├── Justfile                   # Build commands
├── Dockerfile                 # Multi-stage Docker build
├── compose.yml                # Docker Compose for local dev
├── parse-dmarc.service        # systemd service file
├── zeabur.yml                 # Zeabur deployment template
├── render.yaml                # Render deployment config
├── Northflank.json            # Northflank deployment config
├── ROADMAP.md                 # Product roadmap
├── CONTRIBUTING.md            # Contribution guidelines
├── .goreleaser.yml            # Release automation
└── .github/workflows/ci.yml   # CI/CD pipeline

Read the full file on GitHub · 428 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. 2d ago Changed · +1 lines · +40 tokens per session 0af188929afb
  2. 8d ago First seen · 427 lines · 4,050 tokens per session scan A 84adcfc4f13a

Subscribe to this mod's changes

dmarcguard CLAUDE.md is an instructions file published in the GitHub repository dmarcguardhq/dmarcguard (200 stars, last pushed 3d ago), licensed Apache-2.0. It adds 4,090 tokens to every session, about $0.0204 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.

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