day3 MCP Server

by mopraio.github.Mopra/day3v1.0.0

Draft email campaigns in day3 from Claude Code, Cursor or VS Code as editable composer blocks.

1remoteofficial registry

context tax

needs auth

security

92/100

cold start

hosted

freshness

Active3d ago

Our reading of day3, from the data

day3 is a email MCP server from mopra, listed in the official MCP Registry.

Its endpoint requires sign-in or an API key just to list tools, so we haven't measured its token cost; we never use real credentials.

Maintenance is active: the last public signal was 3 days ago (2026-10-15). For comparison, 75% of email servers are active or maintained.

With 1 GitHub stars it ranks #183 of 932 email servers we index.

It runs as a hosted endpoint, so there is nothing to install.

Install day3 MCP server

claude mcp add --transport http day3-app https://go.day3.app/api/mcp

{
  "mcpServers": {
    "day3-app": {
      "url": "https://go.day3.app/api/mcp"
    }
  }
}

{
  "mcpServers": {
    "day3-app": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://go.day3.app/api/mcp"
      ]
    }
  }
}

Or add it as a custom connector under Settings → Connectors. The config above bridges via mcp-remote.

{
  "servers": {
    "day3-app": {
      "type": "http",
      "url": "https://go.day3.app/api/mcp"
    }
  }
}

{
  "mcpServers": {
    "day3-app": {
      "serverUrl": "https://go.day3.app/api/mcp"
    }
  }
}

Remote endpoints

streamable-httphttps://go.day3.app/api/mcp

Security signals

92/100 — no known issues found as of 2026-10-19, from the checks below. This is not a guarantee of safety; review what a server can do before connecting it.

Deductions

No license detected-5
No security policy (SECURITY.md)-3

Checks

✓Repository hygiene (archived, activity, license, security policy)
○Package metadata (install scripts, provenance) — pending
○Tool descriptions (prompt-injection and hidden-text heuristics) — pending
○Source scan (secrets, CVEs, risky code) by vectra-guard — pending

Scan it yourself before installing with vectra-guard, the open-source agent security CLI. Scoring rules

Freshness

Active — last maintenance signal 3d ago. The newest of the signals below sets the band.

Last commit (default branch)
2026-10-15 · 3d ago · GitHub
Latest release
no data · GitHub
Package published
no data · npm/PyPI
Registry entry updated
2026-10-11 · 7d ago · official registry · v1.0.0

How it compares in Email

Against the most-starred email servers we index. Token cost is per model turn, measured from each server's live tool list.

Server	Stars	Tools	Tokens / turn	Freshness	Runs
day3 (this)	1	—	not measured	Active	hosted
Inbox Zero	12,649	—	not measured	Active	hosted
Useplunk	5,524	—	not measured	Active	local
Google Workspace	3,370	—	not measured	Active	—
OpenOSINT	1,776	—	not measured	Active	local
emailmd	1,382	3	954	Active	local + hosted

All email MCP servers

FAQ

›How do I install the day3 MCP server in Claude Code?

Run: claude mcp add --transport http day3-app https://go.day3.app/api/mcp. For Cursor, VS Code, Claude Desktop and Windsurf, use the install tabs above.

›Does day3 require an API key?

No required environment variables are declared in its published metadata.

›Can I use day3 as a remote (hosted) MCP server?

Yes. It is a hosted MCP server; connect to its URL with any client that supports remote MCP.

›Is day3 in the official MCP registry?

Yes, as io.github.Mopra/day3.

Sources and method

Official MCP Registry entry: updated 2026-10-11
GitHub repository: fetched 2026-10-19
Security signals, computed by us: 2026-10-19
Last checked against all sources: 2026-10-19

The description, packages and links come from the maintainer's own published metadata. Token cost, security signals, freshness and the reading above are MCPSkillHub's own measurements; see the methodology. Spot an error? Request a correction or claim the listing.