Nitrosend

What the Nitrosend MCP server does

The Nitrosend MCP server exposes Nitrosend's email marketing capabilities to MCP-compatible AI clients. It supports reading contacts, segments, flows, campaigns, and account status; composing emails; creating multi-step automations; configuring campaigns; managing lists and tags; and importing contacts.

Delivery-oriented tasks include previewing email content, running spam checks, sending test messages, approving campaigns, scheduling them, and reviewing open, click, and unsubscribe metrics. The available account and brand context can also be inspected before an agent performs work.

How it works

The preferred connection is Nitrosend's remote MCP service at https://api.nitrosend.com/mcp. Clients that support HTTP can connect directly and usually authenticate through OAuth in a browser. Claude Desktop, Claude.ai, and Cowork use Nitrosend's connector interface; Cursor also provides a marketplace plugin. Other documented clients can be configured with the remote URL.

For stdio-only clients or local development, the npm package @nitrosend/mcp acts as a bridge. It requires Node.js 18 or newer and can authenticate with an API key or bearer token. The bridge communicates with the Nitrosend MCP endpoint rather than providing a separate local email service.

OAuth sessions retain the selected account and brand across requests, reconnects, and token refreshes. nitro_get_status reports the current and available accounts and brands. nitro_select_account changes the active account for subsequent calls, and nitro_select_brand chooses a brand within that account. API-key connections are fixed to the account and brand associated with the key.

Setup and configuration

For a remote connection, configure the client with the Nitrosend MCP URL and complete its OAuth flow. Claude Code, VS Code, Windsurf, Codex CLI, and Zed each provide documented HTTP configuration paths. Cursor can use its marketplace plugin or a manual MCP configuration.

A stdio configuration runs npx -y @nitrosend/mcp and passes NITROSEND_API_KEY, using a value created under Brand → API Keys in the Nitrosend dashboard. NITROSEND_BEARER_TOKEN is an alternative credential. NITROSEND_API_URL can replace the default endpoint, and NITROSEND_BRAND_SID can force a fixed brand for the stdio bridge. The fixed-brand option sends X-Brand-SID only when it is set.

Tools and capabilities

The Nitrosend MCP server covers these operational areas:

• Read contacts, segments, flows, campaigns, and account status.
• Create email content, campaign setups, and multi-step flows.
• Import contacts and manage lists, segments, and tags.
• Preview messages, check for spam issues, and send tests.
• Approve, schedule, and send campaigns.
• Review opens, clicks, unsubscribes, and related trends.
• Ingest image assets for templates or campaigns using small inline data, public URLs, or a direct-upload flow.

For larger local images, the client should create an upload through nitro_ingest, upload the bytes to the returned URL, and pass the resulting signed identifier back. This keeps large binary payloads out of the MCP conversation.

Limitations and notes

Nitrosend plan limits still apply to sending volume, seats, AI actions, and paid add-ons, even though the generally available MCP, API, and CLI surface is available on all plans. The free plan includes 8,000 emails initially and 500 additional free emails each month.

OAuth account and brand switching changes the active MCP context; it does not edit brand settings. nitro_set_brand_kit changes the Brand Kit for the current brand, including items such as colors, logo, sender details, and voice. API-key connections cannot switch accounts or brands with the selection tools. For Claude's standard connector setup, use the remote connector rather than installing the CLI or stdio bridge.