@nitrosend/mcp

Optional stdio bridge for Nitrosend. Most clients should connect directly to Nitrosend's remote MCP server at https://api.nitrosend.com/mcp; this package exists for stdio-only clients and local development.

All plans, including free plans, have full access to the generally available Nitrosend MCP/API/CLI surface. Plan limits still apply to send volume, seats, AI action allowances, and paid add-ons. The Free plan includes 8,000 free emails up front, then 500 free emails every month.

For Claude Desktop, Claude.ai, and Claude Cowork, use the remote MCP connector UI. Do not install @nitrosend/cli or this stdio bridge for the standard Claude connector setup.

Manage contacts, compose emails, build automated flows, and launch campaigns through natural language.

For image media used in templates or campaigns, MCP should orchestrate rather than carry large bytes. Small chat-attached images can use nitro_ingest with kind=image and image_data; public images can use image_url when Nitro-hosted permanence is desired; larger local files should call nitro_ingest(upload: {kind: "image", filename, content_type, byte_size, checksum}), PUT bytes to direct_upload.url, then pass the returned signed_id to nitro_ingest.

---

Setup by client

Most clients support OAuth — sign in via your browser, no API keys needed.

Claude Code

claude mcp add --transport http nitrosend https://api.nitrosend.com/mcp

Or add to .mcp.json:

{
  "mcpServers": {
    "nitrosend": {
      "type": "http",
      "url": "https://api.nitrosend.com/mcp"
    }
  }
}

OAuth sign-in happens automatically on first use.

---

Claude Desktop

Go to Settings → Connections → Add Custom Connector and enter:

https://api.nitrosend.com/mcp

---

Claude.ai (web + mobile)

Go to Settings → Connectors → Add custom connector and enter:

https://api.nitrosend.com/mcp

---

Cursor

Add to .cursor/mcp.json:

{
  "mcpServers": {
    "nitrosend": {
      "url": "https://api.nitrosend.com/mcp"
    }
  }
}

Cursor handles Nitrosend as a direct remote MCP server. On first use, it prompts for OAuth sign-in.

---

VS Code (Copilot)

Add to .vscode/mcp.json:

{
  "servers": {
    "nitrosend": {
      "type": "http",
      "url": "https://api.nitrosend.com/mcp"
    }
  }
}

VS Code handles OAuth automatically via its built-in MCP auth flow.

---

Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "nitrosend": {
      "serverUrl": "https://api.nitrosend.com/mcp"
    }
  }
}

Windsurf supports OAuth natively for HTTP servers — sign in via your browser on first use.

---

Codex CLI

codex mcp add nitrosend --url https://api.nitrosend.com/mcp
codex mcp login nitrosend

Or add to ~/.codex/config.toml:

[mcp_servers.nitrosend]
url = "https://api.nitrosend.com/mcp"

Then run codex mcp login nitrosend to authenticate via OAuth.

---

Zed

Add to your Zed settings:

{
  "context_servers": {
    "nitrosend": {
      "url": "https://api.nitrosend.com/mcp"
    }
  }
}

---

Any other MCP client

If your client supports HTTP/SSE transport, point it at:

https://api.nitrosend.com/mcp

If your client only supports stdio, use this bridge package with an API key:

{
  "command": "npx",
  "args": ["-y", "@nitrosend/mcp"],
  "env": {
    "NITROSEND_API_KEY": "nskey_live_..."
  }
}

Get your API key at Brand → API Keys in the Nitrosend dashboard.

---

What you can do

Once connected, your agent can:

• Read — query contacts, segments, flows, campaigns, and account status
• Compose — create emails with sections, build multi-step flows, set up campaigns
• Manage — import contacts, create segments, manage lists and tags
• Deliver — preview emails, run spam checks, send tests, approve and schedule campaigns
• Insights — view open/click/unsubscribe metrics and trends

Account and brand context

For OAuth connections, Nitrosend stores both the current account and the current brand per user and OAuth application. Ask your agent to call nitro_get_status first: it shows current_account and available_accounts alongside current_brand and available_brands.

If the task is for a different account than the one shown, call nitro_select_account with the target account_id. The switch takes effect on the next tool call. Then call nitro_select_brand to pick a brand within that account. The selected brand persists across the session and across token refreshes until you switch again.

nitro_select_account and nitro_select_brand only change the active MCP context. nitro_set_brand_kit edits the Brand Kit for the current brand, such as colors, logo, sender details, and voice.

API key connections are pinned to the API key's account and brand and cannot switch with nitro_select_account or nitro_select_brand. For stdio bridge deployments that must force a single brand, set NITROSEND_BRAND_SID; the bridge will send X-Brand-SID only when that variable is present.

Environment variables

Variable	Description
NITROSEND_API_KEY	API key (nskey_live_...) — for stdio transport
NITROSEND_BEARER_TOKEN	OAuth bearer token — alternative to API key
NITROSEND_BRAND_SID	Optional fixed-brand override for the stdio bridge. Sends X-Brand-SID only when set.
NITROSEND_API_URL	Override API endpoint (default: https://api.nitrosend.com/mcp)

Requirements

• Node.js 18+

License

MIT