Email, forms and notifications
Email, forms, notifications, social posting, meetings and phone numbers as APIs. 8 resources; API, key, license and embedding quoted from each site's own pages, checked Oct 24, 2026.
Fillo
You stop writing a new backend, upload flow and response inbox every time your product needs another feedback, intake or support form, and your coding agent can create and publish the form itself.
APICommercial OK
SuprSend
You stop hand-building channel routing, templates, digests and unsubscribe preferences for every notification, and product people can change the flows without a code deploy.
APIFree tierCommercial OK
html.contact
A static or AI-generated site gets a working contact form without writing or hosting any server code.
APIFree tierCommercial OK
Postproxy
You skip building and maintaining a separate OAuth flow, media rules and retry logic for every social network; one payload goes out and you get a per-platform status back.
APICommercial OK
Dial
An agent can place a real phone call or receive an SMS code without you stitching together a telecom provider, speech-to-text and text-to-speech yourself.
API (paid)Commercial: conditions
MeetStream
You can build a notetaker or a live voice agent for meetings without writing and maintaining a separate bot integration for each video-call platform.
API (paid)Free tierCommercial OK
Firma.dev
You add legally recognised signing (ESIGN, UETA, eIDAS) to your app without a per-seat e-signature subscription or sending users to another vendor's site.
API (paid)Free tierCommercial OK
Atomic Mail Agentic
An agent can get a working two-way mailbox without a human signing up, verifying a domain or entering a card, so sign-up confirmations, replies and agent-to-agent mail can run unattended.
APIFree tierCommercial OK
Side by side
| Resource | API | Key | Data download | Commercial use | Embed |
|---|---|---|---|---|---|
| Fillo A hosted form backend with React and DOM SDKs that render forms as native fields inside your own app (no iframe) and handle validation, file uploads to your own S3/R2/Drive/Box, versioned responses, webhooks and exports, plus a REST management API and a remote MCP server. |
Official API · Free tier | Yes | — | Commercial use OK | Embedding with conditions |
| SuprSend A notification API and dashboard: your backend triggers one workflow and SuprSend sends it over email, SMS, push, Slack, WhatsApp or an in-app inbox through the providers you connect, with templates, batching/digests, user preferences, multi-tenant branding, a CLI and a hosted MCP server. |
Official API · Free tier | Yes | — | Commercial use OK | Embedding with conditions |
| html.contact A hosted endpoint for plain HTML forms: point a form's action at your html.contact URL and submissions are emailed to verified recipients, stored in a dashboard, spam-screened, limited to your allowed domains and exportable as CSV. |
Official API · Free tier | Yes | — | Commercial use OK | Can be embedded |
| Postproxy A REST API (with SDKs and an MCP server) that publishes posts to 11 social networks such as Instagram, LinkedIn, X, TikTok and YouTube from one request, and reads and answers comments, DMs and Google Business reviews. |
Official API · Free tier | Yes | — | Commercial use OK | Embedding with conditions |
| Dial An API, CLI and MCP server that gives an AI agent its own phone number for voice calls with transcription, two-way SMS, WhatsApp and iMessage, with every channel delivered to one webhook or event stream. |
Official API · Paid | Yes | — | Commercial use with conditions | Embedding unclear |
| MeetStream An API that sends a named bot into Zoom, Google Meet or Microsoft Teams calls and gives you the recording, separate per-participant audio and video, transcripts and a live WebSocket media stream, with webhooks for bot status. |
Official API · Paid | Yes | — | Commercial use OK | Embedding unclear |
| Firma.dev A pay-per-envelope e-signature REST API with embeddable, white-label template and signing editors, isolated workspaces per customer, webhooks and audit trails, aimed at SaaS apps that want document signing inside their own product. |
Official API · Paid | Yes | — | Commercial use OK | Can be embedded |
| Atomic Mail Agentic An email service that lets an AI agent create its own username@atomicmail.ai inbox by solving a proof-of-work challenge, then send, receive and search mail through the standard JMAP protocol, an MCP server or a CLI skill. |
Official API · Free | Yes | — | Commercial use OK | Embedding unclear |