# SendFlit

> Official SDKs and API reference for the SendFlit transactional email API

- [Introduction](https://docs.sendflit.com/index.md): SendFlit is a transactional email API for developers and AI agents. Send, track and manage email with one API key.
- [Quickstart](https://docs.sendflit.com/quickstart.md): Verify a domain, create an API key, and send your first email with the API or any SDK.
- [Domains](https://docs.sendflit.com/concepts/domains.md): How sending domains work: DKIM, SPF and DMARC records, verification, and why verification is required.
- [API keys and scopes](https://docs.sendflit.com/concepts/api-keys.md): Create, scope, rotate and revoke SendFlit API keys.
- [Emails and their lifecycle](https://docs.sendflit.com/concepts/emails.md): What happens to an email from the moment you send it: statuses, events, scheduling, cancellation and tracking.
- [Send a welcome email from Node.js](https://docs.sendflit.com/tutorials/node-welcome-email.md): Build a sign-up route that sends a welcome email safely, using the SendFlit Node.js SDK and an idempotency key.
- [Handle bounces and complaints with webhooks](https://docs.sendflit.com/tutorials/handle-bounces.md): Receive SendFlit webhooks, verify their signatures, and react to bounces, complaints and delivery events.
- [Build and send a React email template](https://docs.sendflit.com/tutorials/react-email-template.md): Create a reusable email template with React components, render it to HTML, preview it, and send it through the SendFlit API.
- [Let an AI agent send email with MCP](https://docs.sendflit.com/tutorials/ai-agent-mcp.md): Connect an MCP-compatible AI agent to SendFlit, list the tools it can use, and send an email through the MCP server.
- [Sign-up forms](https://docs.sendflit.com/guides/signup-forms.md): Build a sign-up form for your website, customise its look and questions, and understand how signups reach your contacts.
- [Idempotency and safe retries](https://docs.sendflit.com/guides/idempotency.md): Make email sends safe to retry after timeouts and failures by using idempotency keys correctly.
- [Batch sending](https://docs.sendflit.com/guides/batch-sending.md): Send up to 100 emails in one request, read per-message results, and handle partial failures.
- [SMTP relay](https://docs.sendflit.com/guides/smtp.md): Send email through SendFlit from any app or server that can only speak SMTP.
- [Switching from Resend](https://docs.sendflit.com/guides/switching-from-resend.md): Move an existing Resend integration to SendFlit by changing the API key and base URL.
- [MCP server](https://docs.sendflit.com/guides/mcp-server.md): Let AI agents use a SendFlit account through the Model Context Protocol.
- [DNS guides](https://docs.sendflit.com/guides/dns/overview.md): Add the records SendFlit needs at your DNS provider. Pick your provider for a step-by-step guide.
- [Add SendFlit DNS records at Cloudflare](https://docs.sendflit.com/guides/dns/cloudflare.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Cloudflare, then verify it with SendFlit.
- [Add SendFlit DNS records at Gandi](https://docs.sendflit.com/guides/dns/gandi.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Gandi, then verify it with SendFlit.
- [Add SendFlit DNS records at GoDaddy](https://docs.sendflit.com/guides/dns/godaddy.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at GoDaddy, then verify it with SendFlit.
- [Add SendFlit DNS records at DreamHost](https://docs.sendflit.com/guides/dns/dreamhost.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at DreamHost, then verify it with SendFlit.
- [Add SendFlit DNS records at Hetzner](https://docs.sendflit.com/guides/dns/hetzner.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Hetzner, then verify it with SendFlit.
- [Add SendFlit DNS records at Hostinger](https://docs.sendflit.com/guides/dns/hostinger.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Hostinger, then verify it with SendFlit.
- [Add SendFlit DNS records at IONOS](https://docs.sendflit.com/guides/dns/ionos.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at IONOS, then verify it with SendFlit.
- [Add SendFlit DNS records at Namecheap](https://docs.sendflit.com/guides/dns/namecheap.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Namecheap, then verify it with SendFlit.
- [Add SendFlit DNS records at Porkbun](https://docs.sendflit.com/guides/dns/porkbun.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Porkbun, then verify it with SendFlit.
- [Add SendFlit DNS records at Squarespace](https://docs.sendflit.com/guides/dns/squarespace.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Squarespace, then verify it with SendFlit.
- [Add SendFlit DNS records at STRATO](https://docs.sendflit.com/guides/dns/strato.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at STRATO, then verify it with SendFlit.
- [Add SendFlit DNS records at Vercel](https://docs.sendflit.com/guides/dns/vercel.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Vercel, then verify it with SendFlit.
- [Add SendFlit DNS records at Name.com](https://docs.sendflit.com/guides/dns/name-com.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Name.com, then verify it with SendFlit.
- [Add SendFlit DNS records at Dynadot](https://docs.sendflit.com/guides/dns/dynadot.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Dynadot, then verify it with SendFlit.
- [Add SendFlit DNS records at Bluehost](https://docs.sendflit.com/guides/dns/bluehost.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Bluehost, then verify it with SendFlit.
- [Add SendFlit DNS records at HostGator](https://docs.sendflit.com/guides/dns/hostgator.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at HostGator, then verify it with SendFlit.
- [Add SendFlit DNS records at Network Solutions](https://docs.sendflit.com/guides/dns/network-solutions.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Network Solutions, then verify it with SendFlit.
- [Add SendFlit DNS records at Wix](https://docs.sendflit.com/guides/dns/wix.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Wix, then verify it with SendFlit.
- [Add SendFlit DNS records at Google Cloud DNS](https://docs.sendflit.com/guides/dns/google-cloud-dns.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Google Cloud DNS, then verify it with SendFlit.
- [Add SendFlit DNS records at Azure DNS](https://docs.sendflit.com/guides/dns/azure-dns.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at Azure DNS, then verify it with SendFlit.
- [Add SendFlit DNS records at DigitalOcean](https://docs.sendflit.com/guides/dns/digitalocean.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at DigitalOcean, then verify it with SendFlit.
- [Add SendFlit DNS records at OVHcloud](https://docs.sendflit.com/guides/dns/ovhcloud.md): Step-by-step: publish the DKIM, SPF and DMARC records for your domain at OVHcloud, then verify it with SendFlit.
- [Add SendFlit DNS records at any provider](https://docs.sendflit.com/guides/dns/other-providers.md): The same steps work at any DNS provider: find the DNS page for your domain, add three TXT records, then verify.
- [SDK overview](https://docs.sendflit.com/sdks/overview.md): Install a SendFlit SDK for Node.js, Python, Go, Ruby, PHP, Java or .NET, and see which methods each one provides.
- [Node.js](https://docs.sendflit.com/sdks/node.md): Send transactional email from Node.js 18+ with the @sendflit/sdk package: send, batch, manage emails and domains, retry safely, and verify webhooks.
- [Python](https://docs.sendflit.com/sdks/python.md): Send transactional email from Python 3.9+ with the sendflit package: send, batch, idempotency keys, domains, suppressions and webhook verification.
- [Go](https://docs.sendflit.com/sdks/go.md): Send transactional email from Go with github.com/Sendflit/sendflit-go: context-aware sends, batch, domains, suppressions, errors and webhook verification.
- [Ruby](https://docs.sendflit.com/sdks/ruby.md): Send transactional email from Ruby 2.7+ with the sendflit gem: keyword-argument sends, batch, domains, suppressions, errors and webhook verification.
- [PHP](https://docs.sendflit.com/sdks/php.md): Send transactional email from PHP 7.4+ with the sendflit/sendflit Composer package: array-based sends, batch, attachments, domains, suppressions, errors and webhook verification.
- [Java](https://docs.sendflit.com/sdks/java.md): Send transactional email from Java 17+ with the com.sendflit:sendflit artifact: builder-based sends, batch, attachments, domains, suppressions, errors and webhook verification.
- [.NET](https://docs.sendflit.com/sdks/dotnet.md): Send transactional email from .NET 6+ with the SendFlit NuGet package: async sends, batch, attachments, domains, suppressions, errors and webhook verification.
- [React email templates](https://docs.sendflit.com/sdks/templates/react-email.md): Build email-safe templates with React components and render them to HTML for SendFlit.
- [API overview](https://docs.sendflit.com/reference/api-overview.md): Base URL, versioning, authentication, endpoints and conventions for the SendFlit v1 REST API.
- [Errors, retries and limits](https://docs.sendflit.com/reference/errors.md): HTTP status codes, safe retries with idempotency keys, batch behavior and sending limits.
- [Webhooks](https://docs.sendflit.com/reference/webhooks.md): Receive delivery, bounce, complaint and engagement events from SendFlit, verify each request's signature, and handle retries safely.
- [Security](https://docs.sendflit.com/reference/security.md): How SendFlit protects API keys, sending domains, webhook deliveries and email data, and what you should do on your side.
- [Changelog](https://docs.sendflit.com/reference/changelog.md): Release history for the SendFlit API and SDKs.
- [List Keys](https://docs.sendflit.com/api-reference/list-keys.md)
- [Create Key](https://docs.sendflit.com/api-reference/create-key.md)
- [Update Key](https://docs.sendflit.com/api-reference/update-key.md): Rename a key, or change what an agent key may do. Takes effect on its next request.
- [Revoke Key](https://docs.sendflit.com/api-reference/revoke-key.md)
- [List Domains](https://docs.sendflit.com/api-reference/list-domains.md)
- [Add Domain](https://docs.sendflit.com/api-reference/add-domain.md)
- [Domain Records](https://docs.sendflit.com/api-reference/domain-records.md): Full DNS record set for manual setup (neutral, white-label).
- [Update Domain](https://docs.sendflit.com/api-reference/update-domain.md): Change the Return-Path subdomain. The records move with it, so the domain goes back to waiting on DNS for them.
- [Domain Deliverability](https://docs.sendflit.com/api-reference/domain-deliverability.md): A 0-100 deliverability score with the specific, actionable reasons behind it.
- [Domain Deliverability Assistant](https://docs.sendflit.com/api-reference/domain-deliverability-assistant.md): The same score, read by the AI layer into a one-paragraph plain- language explanation and a single prioritized next step — for someone who wants "what do I actually do" rather than a checklist.
- [Verify Domain](https://docs.sendflit.com/api-reference/verify-domain.md): `recheck=true` is the Verify button itself (not the page's own polling): also asks the mail provider to look at the Return-Path records again now.
- [List Suppressions](https://docs.sendflit.com/api-reference/list-suppressions.md)
- [Add Suppression](https://docs.sendflit.com/api-reference/add-suppression.md)
- [Remove Suppression](https://docs.sendflit.com/api-reference/remove-suppression.md)
- [Send](https://docs.sendflit.com/api-reference/send.md): Send one email. Pass an `Idempotency-Key` header on retry-sensitive calls: retrying the exact same request with the same key replays the original result (including a prior failure) instead of sending twice. Reusing the key with a different body is rejected as a client error.
- [Send Batch](https://docs.sendflit.com/api-reference/send-batch.md): Send up to 100 emails in one call. The `Idempotency-Key` header (see /email above) covers the whole batch — retrying the same batch with the same key replays the original per-item results rather than resending.
- [Get Email](https://docs.sendflit.com/api-reference/get-email.md)
- [Cancel Scheduled](https://docs.sendflit.com/api-reference/cancel-scheduled.md)
- [List Emails](https://docs.sendflit.com/api-reference/list-emails.md)
- [List Webhooks](https://docs.sendflit.com/api-reference/list-webhooks.md)
- [Create Webhook](https://docs.sendflit.com/api-reference/create-webhook.md)
- [Delete Webhook](https://docs.sendflit.com/api-reference/delete-webhook.md)
- [Usage](https://docs.sendflit.com/api-reference/usage.md)

## OpenAPI Specs

- [openapi-v1](/openapi/openapi-v1.json)


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