Zernio

Zernio is a developer-focused API that lets products and AI agents post to sixteen social networks, run ads, and send WhatsApp, SMS and calls through one key, with an MCP server and a free tier of 2 accounts.

Zernio is a marketing infrastructure platform aimed at developers and AI agents that need to reach customers across many channels without building each integration separately. Instead of applying for platform approvals, rotating tokens and tracking rate limits network by network, a team connects accounts once and talks to everything through a single API key. The company states that it works only with official platform APIs and absorbs the maintenance work when those platforms change. The product is split into three areas. The social layer covers posting, scheduling, replying to comments and DMs, and pulling analytics across sixteen networks, including Instagram, TikTok, X, LinkedIn, Facebook, Threads, YouTube, Pinterest, Bluesky, Reddit, Snapchat, Discord, Telegram, Slack and Google Business. The advertising layer wraps seven ad managers so campaigns can be launched, conversions sent back and spend read from one place. The communication layer lets a user buy a phone number and then send WhatsApp messages, SMS and calls from it, with replies collected in one inbox. A Blogs API also publishes and manages articles on WordPress and Shopify. In practice, a developer sends a single request, such as a POST to the posts endpoint, listing the platforms and account IDs to publish to, and the same payload can go out as an Instagram reel, a LinkedIn post and a TikTok video. Replies return through webhooks rather than polling. Zernio publishes setup pages for Claude Code, Cursor, Codex, OpenClaw, Grok bot and Hermes, and the site mentions an MCP server, a Node SDK and a CLI. The homepage claims a path from signup to a first post, message, report or ad in under five minutes. Among alternatives, Zernio sits between consumer scheduling apps and the do-it-yourself route of integrating each platform API directly. It suits product teams, agencies and agent builders who want programmatic control over many channels, though it is built around code and agent workflows rather than a visual content calendar.