Nitrosend

Nitrosend is AI-Native Email — campaigns, automation flows and transactional email, run end to end from Claude, ChatGPT, Codex, Cursor or any MCP client.

CommunityOnlineNo sign-inGlobalFreeCan modify data

What it can do

  • Nitro Get Status: Get current account context, sender identity, dashboard links, readiness, onboarding status, and recommendations.
  • Nitro Select Account: Switch this OAuth MCP connection to an account listed by nitro_get_status; the next call uses it. Credential-authenticated connections are pinned and cannot switch.
  • Nitro Select Brand: Select the current brand for this OAuth MCP connection. Use this instead of passing brand_sid to other tools. Credential-authenticated connections are pinned to one brand and canno

What data it sees

Do you need an account

No: the server works without sign-in

Nitrosend is AI-Native Email — campaigns, automation flows and transactional email, run end to end from Claude, ChatGPT, Codex, Cursor or any MCP client. No dashboard required.

What your agent can do

  • Audience — import, search and update contacts; manage lists, tags and events; build and preview segments with live counts
  • Compose — branded email templates, multi-step automation flows, and email or SMS campaigns, styled from a brand kit scraped off your own site
  • Review — spam and preflight checks, rendered previews, and real test sends before anything goes out
  • Deliver — approve, schedule and control sends, with approval always a separate step
  • Domains — add a sending domain, get its DNS records, and verify them
  • Insights — opens, clicks, unsubscribes and trends, against benchmarks
  • Plus — transactional sends, a reply inbox your agent can work, BYO sending providers, billing, and searchable docs

Composing never sends. Compose tools only ever produce drafts; delivery is a separate, explicitly approved call. An agent can build an entire campaign with no risk of mailing your list by accident.

Free forever on $0 — full MCP access, 8,000 emails up front then 500/month, and unlimited contacts on every plan. No credit card.

How to connect

How to connect Nitrosend to Claude

The server address to paste into Claude settings:

https://nitrosend--nitrosend.run.tools

  1. Open Claude (claude.ai or the desktop app).
  2. Go to Settings → Connectors.
  3. Click Add custom connector.
  4. Paste the server address copied below into Remote MCP server URL and click Add.
  5. In a chat, click + → Connectors and switch the new connector on.

Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

Authorization

After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

How to connect Nitrosend to ChatGPT

The server address to paste into ChatGPT settings:

https://nitrosend--nitrosend.run.tools

  1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
  2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
  3. Open Settings → Connectors and click Create.
  4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
  5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
  6. In a new chat open + → Apps/Connectors and enable the connector.

OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

Authorization

On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

How to connect Nitrosend to Cursor

The server address to paste into Cursor settings:

https://nitrosend--nitrosend.run.tools

Fastest: click Open in Cursor below and confirm the prompt.

Manually:

  1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
  2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
  3. Save the file. The server appears in the MCP list; authorize it there if asked.

Authorization

If the service needs sign-in, an authorize button appears next to the server in the MCP list.

Server tool list (28)

Raw names from tools/list. Only developers need these.

nitro_get_statusGet current account context, sender identity, dashboard links, readiness, onboarding status, and recommendations.
nitro_select_accountSwitch this OAuth MCP connection to an account listed by nitro_get_status; the next call uses it. Credential-authenticated connections are pinned and cannot switch.
nitro_select_brandSelect the current brand for this OAuth MCP connection. Use this instead of passing brand_sid to other tools. Credential-authenticated connections are pinned to one brand and cannot switch.
nitro_queryQuery any Nitrosend entity. Returns paginated results.
nitro_search_contactsSearch contacts by email, name, or phone. Returns summary list or full profile.
nitro_set_brand_kitSet Brand Kit from a website, typed fields, document, or logo URL. Fields override scraping; async is URL-only.
nitro_ingestValidate and store an image in the brand library. Use image_data for small images, upload then signed_id for local files, or image_url for external/generated assets. Returns a durable email URL.
nitro_manage_audienceCreate or update contacts, manage subscriptions, lists, events, segments, and tags. Custom contact fields belong in attributes.data. For more than 100 contact writes, use nitro_import_contacts with CSV.
nitro_manage_outreachDiscover named people for outreach: intent, estimate, then start. Companies are evidence, never recipients. start requires the quoted USD-cent spend cap and idempotency key.
nitro_define_segmentPreview or persist a filtered contact segment. preview_only defaults true; set false and provide name to save.
nitro_import_contactsImport up to 100 inline contacts or use the CSV upload/finalize path for up to 250k. Existing subscription state is preserved unless opt_in is explicit; SMS opt-in must be explicit.
nitro_manage_templateCreate, edit, or clone a reusable email template. For a creative design, start with composition_mode=intent and follow its exact next_call. Exact edits use template_id, section_updates, and if_version; based_on clones. Use nitro_compose_campaign for broadcasts.
nitro_compose_flowCreate or edit an automation-flow draft; never activates it. For creative email, start with composition_mode=intent and follow its exact next_call. Multi-email flows choose routes per action_name. replace requires flow_id, confirm, and the draft revision; patch preserves other nodes. Activation uses nitro_control_delivery.
nitro_compose_campaignCreate or edit an email/SMS broadcast draft; never delivers it. For creative email, start with composition_mode=intent and follow its exact next_call. patch preserves omitted fields; replace requires campaign_id and confirm, and clears omitted audience or schedule. Use nitro_compose_flow for automation and nitro_send_message for transactional mail.
nitro_manage_domainsAdd, verify, diagnose, list, or remove sending domains. Add returns customer DNS records; check_dns validates DNS and tracking HTTPS. Receiving MX appears only after forward-all exists, protecting the active mailbox provider.
nitro_configure_accountRead or configure sender defaults and test recipients. Use nitro_get_status for readiness; from_email must be authorized by a verified sending domain.
nitro_review_deliveryRead-only content and readiness review with validation, spam/SMS analysis, preflight, and previews. Flow review needs exact revision_id; this never approves or sends.
nitro_send_test_messageSend one real email/SMS test for a template, campaign, or exact flow revision. Never approves or sends to an audience.
nitro_control_deliveryApprove or control flow/campaign delivery after review. Requires the reviewed brand sid; resume never publishes a draft, and flow publication requires its exact revision.
nitro_get_insightsGet email analytics with trends, benchmarks, and recommendations.
nitro_configure_providersConfigure BYO email provider credentials or check provider status.
nitro_set_memoryRead or update the AI memory document. Operations: read (get current), update (replace entirely), patch (replace a ## section by heading), append (add text to end).
nitro_manage_billingRead billing/plans, create operator-approved subscription or add-funds checkout URLs, and poll status. This tool never pays; the operator opens the URL. Prepaid balance is separate from plans.
nitro_send_messageSend one transactional email/SMS now. Use nitro_compose_campaign for broadcasts and nitro_compose_flow for sequences. Reuse idempotency_key only for an exact retry.
nitro_inboxRead the agent queue or mailbox. Follow exact next_calls for older or truncated thread content.
nitro_inbox_actionMutate an agent inbox item or mailbox thread. Commands: send_reply, send_reply_test, mark_handled, request_human, release_to_agent, mark_quarantine.
nitro_request_supportSubmit support only when asked or tools cannot resolve the issue; never promote it. Send a complete message within 1500 characters; there is no truncation.
nitro_search_docsSearch Nitrosend guides and API/MCP/CLI/integration references. Ground unestablished product claims in returned excerpts; search again or state what remains unverified.