Email MCP Server for Zed
Wire marginal's hosted email MCP server into Zed and let its AI agent design, launch, and analyze subject line A/B tests without leaving your editor.
Why run marginal inside Zed
Zed's assistant speaks the Model Context Protocol, so it can call external tools directly. Pointing it at marginal turns email experimentation into something you script and iterate on the same way you do code — prompt the agent, inspect the results, refine, repeat.
Because marginal is a hosted email MCP server, there's nothing to deploy. You add one endpoint and a Bearer key, and Zed gains a working email MCP integration.
- No self-hosted server to maintain — marginal runs the infrastructure
- Managed sends with open and click tracking baked in
- Within-test lift metrics so the agent can reason about winners
- Free tier of 100 experiments per month to get started
Configure the Zed MCP connection
Add marginal to Zed's MCP settings using the registry name and your API key. The key starts with marg_live_ and is passed as a Bearer token to the marginal endpoint.
- Endpoint: https://marginal.sh/mcp
- Registry: sh.marginal/mcp
- Auth: Authorization: Bearer marg_live_...
- Restart Zed's agent panel so it picks up the new server
MCP config for Zed
Use this JSON in your Zed MCP configuration. Replace the placeholder with your real marginal API key.
{
"context_servers": {
"marginal": {
"command": {
"path": "npx",
"args": ["-y", "mcp-remote", "https://marginal.sh/mcp"],
"env": {
"MARGINAL_API_KEY": "marg_live_xxxxxxxxxxxxxxxx"
}
}
}
}
}Run a subject line A/B test from Zed
Once connected, the Zed agent can drive the full marginal workflow through four tools. Ask it to draft variants, launch a test, and report back on which subject line won.
This is AI agent email marketing in practice: the model proposes copy, the platform runs the experiment, and lift metrics tell you what to send next.
- generate_variants — produce competing subject lines for a campaign
- launch_test — start a managed subject line A/B test
- get_results — pull open/click rates and within-test lift
- recommend_next — let marginal suggest the follow-up send
- See full tool details at https://marginal.sh/mcp
Get started with marginal
marginal is a hosted email marketing MCP server at marginal.sh. Sign up free, create an API key, and connect https://marginal.sh/mcp from Cursor, Codex, or Claude Desktop.
- 100 experiments/month on the free tier
- Four MCP tools: generate_variants, launch_test, get_results, recommend_next
- Listed in the MCP Registry as sh.marginal/mcp