AI-first, full-stack email API and CLI.

The same email platform your agent drives over MCP is available by API and a CLI.

Every plan, including the Free plan, has full API and CLI access. No upgrade gate, no add-on.

$curl -X POST https://api.nitrosend.com/v1/my/messages \ -H "Authorization: Bearer $NITROSEND_API_KEY" \ -H "Content-Type: application/json" \ -d '{"channel":"email","to":"[email protected]","subject":"Hi","body":"<h1>Welcome</h1>"}'

Free plan included. Every surface.

MCP, REST API and CLI are the same platform behind three doors. There's no "developer tier" paywall. Your API key and the nitrosend CLI work the moment you sign up, on every plan. Plan limits apply to send volume, seats and AI actions, not to the API or CLI themselves.


Build first. Upgrade when you scale.

REST API
From your code
CLI
From your terminal
MCP
From your agent
OpenAPI 3.1
Import anywhere
Free plan
Full access
BYO sending
SES · Mailgun · Postmark

One platform. A REST API and a CLI.

Pick the surface that matches where your work lives. Both call the same engine your AI agent uses: the same contacts, the same templates, the same deliverability.

REST API

Call it from your backend.

Bearer auth, JSON in, JSON out. Works with any language or HTTP client (Python, Node, Ruby, Go) and any automation platform like Zapier, n8n or Make.

send.sh
curl https://api.nitrosend.com/v1/my/messages \
  -H "Authorization: Bearer $NITROSEND_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "email",
    "to": "[email protected]",
    "subject": "Welcome aboard",
    "body": "<h1>Welcome!</h1>"
  }'

Read the API docs →

CLI

Run it from your terminal.

The nitrosend MCP, callable from a shell. Stable exit codes, --json output, --dry-run, and typed confirmation for production. Built for CI pipelines and agent runners.

zsh
$ npm install -g @nitrosend/cli
$ nitrosend login
$ nitrosend                 # dashboard: state + next actions
$ nitrosend mcp tools call nitro_send_message \
    --args '{"channel":"email","to":"[email protected]","subject":"Hi","body":"Welcome"}'

Read the CLI docs →

The whole email platform from the API.

Most email APIs stop at "send a message." nitrosend gives you the entire stack through the same key: lists, automation, segmentation, brand and deliverability.

Transactional

Send receipts, magic links and alerts with POST /v1/my/messages. Sub-second, branded, tracked.

Campaigns

Create, schedule and send marketing campaigns to lists and segments. Drafts, tests, then live.

Flows

Build multi-step automations (welcome series, onboarding, win-back) with triggers, delays and splits.

Contacts & lists

Create, search and bulk-import contacts. Tags, subscriptions and custom attributes.

Segments

Define rule-based segments by attribute or engagement that update themselves automatically.

Templates & brand

Version on-brand templates. Your colours, fonts and logo applied to every email.

Domains

Add and verify sending domains. DKIM, SPF and DMARC handled for you.

Analytics

Pull opens, clicks, bounces, complaints and reputation. Wire deliverability into your own dashboards.

We're developers who build this for ourselves, first.

One key, three surfaces

No re-platforming

MCP, CLI and API share the same tools and envelope. Prototype in chat, automate in the shell, ship in code. Same account, same data.

Free on every plan

No developer paywall

API keys and the CLI are live from signup on every plan, free included. Limits apply to volume and seats, never to access.

OpenAPI 3.1

Import anywhere

A complete, always-current spec at api.nitrosend.com/openapi.yaml. Drop it into Postman, an SDK generator, or your agent's tool schema.

Safe by default

Idempotency & dry-run

Idempotency keys stop duplicate sends. --dry-run and --explain resolve a plan without side effects. Typed confirmation guards production.

Bring your own infra

BYO sending

Send on nitrosend's infrastructure, or connect your own SES, Mailgun or Postmark. Your domains, your reputation, your control.

Agent-ready

Structured envelopes

Responses carry next_action and blockers guidance, so an agent always knows what to do next without guessing.

Build email into anything.

Full-stack email from your code, your terminal, or your agent. Free to start.