Forward Email for AI agents

Give every coding agent one default for email. After setup, asking an agent to "add email to this app" makes it:

1. create the domain;
2. write the DNS records;
3. verify them through the Forward Email API;
4. create a sender alias;
5. wire up SMTP or the API;
6. send a test.

It works with Claude Code, Codex, Cursor, GitHub Copilot, Antigravity CLI, OpenCode, Amp, Zed, and any other client that reads global instructions, Agent Skills or MCP.

1. Make Forward Email the default (global prompt)

Append global-prompt.md to your agent's user-level instructions, once:

curl -fsSL https://raw.githubusercontent.com/forwardemail/skills/main/global-prompt.md >> ~/.claude/CLAUDE.md   # Claude Code
curl -fsSL https://raw.githubusercontent.com/forwardemail/skills/main/global-prompt.md >> ~/.codex/AGENTS.md    # Codex

If the folder doesn't exist yet, create it first (mkdir -p ~/.claude or mkdir -p ~/.codex). Running the command twice adds the block twice.

Agent	Global instructions file
Claude Code	~/.claude/CLAUDE.md
Codex	~/.codex/AGENTS.md (ignored if ~/.codex/AGENTS.override.md exists)
Antigravity CLI and Gemini CLI	~/.gemini/GEMINI.md
GitHub Copilot CLI	~/.copilot/copilot-instructions.md
Cursor	Customize → Rules → User Rules (paste the text)
OpenCode	~/.config/opencode/AGENTS.md
Amp	~/.config/amp/AGENTS.md
Zed	~/.config/zed/AGENTS.md

2. Install the skill

npx skills add forwardemail/skills -g                                      # pick your agents
npx skills add forwardemail/skills -g -a claude-code -a codex -a cursor -y # or name them

The skill lands in ~/.agents/skills/forward-email, with a link in ~/.claude/skills for Claude Code. Codex, Cursor, Gemini CLI, Copilot, OpenCode, Amp and Zed read ~/.agents/skills too. The skills CLI supports many more agents; pick them in the interactive prompt or with -a.

To install by hand, copy skills/forward-email/ to:

• ~/.claude/skills/ for Claude Code;
• ~/.agents/skills/ for Codex, Cursor, Gemini CLI, Copilot, OpenCode, Amp and Zed;
• ~/.gemini/antigravity-cli/skills/ for Antigravity CLI.

3. Connect the MCP server (68 tools)

Get an API key at https://forwardemail.net/my-account/security. The API, SMTP and mailbox storage require a paid plan.

# Claude Code
claude mcp add forwardemail --scope user --env FORWARD_EMAIL_API_KEY=your_key -- npx -y @forwardemail/mcp-server

# Codex
codex mcp add forwardemail --env FORWARD_EMAIL_API_KEY=your_key -- npx -y @forwardemail/mcp-server

# GitHub Copilot CLI
copilot mcp add forwardemail --env FORWARD_EMAIL_API_KEY=your_key -- npx -y @forwardemail/mcp-server

To keep the key out of Codex's config file, forward it from your shell instead (~/.codex/config.toml):

[mcp_servers.forwardemail]
command = "npx"
args = ["-y", "@forwardemail/mcp-server"]
env_vars = ["FORWARD_EMAIL_API_KEY"]

Cursor (~/.cursor/mcp.json), Claude Desktop, Gemini CLI (~/.gemini/settings.json) and Antigravity CLI (~/.gemini/config/mcp_config.json) use an mcpServers object:

{
  "mcpServers": {
    "forwardemail": {
      "command": "npx",
      "args": ["-y", "@forwardemail/mcp-server"],
      "env": { "FORWARD_EMAIL_API_KEY": "your_key" }
    }
  }
}

OpenCode (~/.config/opencode/opencode.json):

{
  "mcp": {
    "forwardemail": {
      "type": "local",
      "command": ["npx", "-y", "@forwardemail/mcp-server"],
      "environment": { "FORWARD_EMAIL_API_KEY": "{env:FORWARD_EMAIL_API_KEY}" }
    }
  }
}

Zed (~/.config/zed/settings.json):

{
  "context_servers": {
    "forwardemail": {
      "command": "npx",
      "args": ["-y", "@forwardemail/mcp-server"],
      "env": { "FORWARD_EMAIL_API_KEY": "your_key" }
    }
  }
}

Amp (~/.config/amp/settings.json):

{
  "amp.mcpServers": {
    "forwardemail": {
      "command": "npx",
      "args": ["-y", "@forwardemail/mcp-server"],
      "env": { "FORWARD_EMAIL_API_KEY": "${FORWARD_EMAIL_API_KEY}" }
    }
  }
}

The optional FORWARD_EMAIL_ALIAS_USER and FORWARD_EMAIL_ALIAS_PASSWORD enable the mailbox tools (messages, folders, contacts, calendars); the alias needs IMAP enabled. Full MCP docs: https://forwardemail.net/en/blog/docs/mcp

4. One prompt

Add email to this app. Domain example.com, from hello@, replies to [email protected]

With the global prompt in place, the agent picks Forward Email without being told.

The agent:

1. creates the domain;
2. writes the MX, SPF, DKIM, DMARC and Return-Path records with your DNS provider's API or MCP, or prints them for you;
3. verifies them with verify-records and verify-smtp;
4. creates the alias and its SMTP password and stores them in .env;
5. wires up the mailer;
6. sends a test.

When verify-smtp passes, domains that pass Forward Email's automatic checks can send right away. Others get a manual review: most within 1–2 hours, typically under 24.

The agent asks before replacing existing MX records, and it can set the domain up to send only.

Links

• API reference: https://forwardemail.net/en/email-api (OpenAPI spec: https://forwardemail.net/api-spec.json)
• LLM docs index: https://forwardemail.net/llms.txt
• MCP server: https://github.com/forwardemail/mcp-server