Most “post everywhere” tools are dashboards. Zernio is the opposite: a developer-first REST API (and a hosted MCP server) that gives apps and AI agents a single authentication model and a single request shape to publish, schedule, and analyze content across 15+ social platforms and 6 ad networks. If you have ever written one integration for the X API, another for Instagram, and a third for LinkedIn — each with its own auth dance and payload quirks — that is the pain it targets.
What you actually get to call
The base URL is https://zernio.com/api/v1, and authentication is a plain bearer
token: an sk_-prefixed key of 64 hex characters (67 total), passed in the
Authorization header and conventionally stored in ZERNIO_API_KEY. Keys are
shown once at creation and kept server-side only as SHA-256 hashes, which is the
sensible default you want from an API vendor.
The publishing flow is small enough to hold in your head: create a profile
(POST /profiles), run a platform’s OAuth handshake (GET /connect/{platform}),
check what’s linked (GET /accounts), then publish or schedule with POST /posts.
A minimal call looks like this:
curl -X POST https://zernio.com/api/v1/posts \
-H "Authorization: Bearer $ZERNIO_API_KEY" \
-d '{"content":"Hello world!","publishNow":true,"platforms":[...]}'
The same surface covers the parts that usually need separate vendors: paid
campaigns through /api/v1/ads (Meta, Google, TikTok, LinkedIn, Pinterest, and X
Ads), per-post and account-level analytics, and reading or replying to comments
and DMs where a platform allows it. Supported networks include Instagram, TikTok,
YouTube, X, LinkedIn, Facebook, Threads, Pinterest, Reddit, Bluesky, WhatsApp,
Telegram, Discord, Snapchat, and Google Business.
The agent angle
Every capability is also exposed through an MCP server, so an AI agent can post, schedule, and pull metrics as MCP tools rather than hand-rolled HTTP calls. That makes Zernio interesting as a building block for an agent that manages a content pipeline end to end — drafting, scheduling, and then reading back engagement to decide what to do next.
Integrating it
There is no library to vendor or service to stand up; you call a hosted endpoint. Official SDKs are listed for Node.js, Python, Go, Ruby, Java, PHP, .NET, and Rust, and the full surface is published as an OpenAPI spec, so you can generate your own client if your language isn’t covered. The developer documentation carries the auth details and endpoint examples.
How settled is it?
This is where you should temper expectations. Zernio does not publish a version
number or a stability statement, and the Java SDK currently sits at 0.0.307 —
a strong hint that this is early, actively moving software rather than a frozen
1.0. Rate limits are not documented yet, which matters a lot for anything posting
at volume, and pricing is described only as “usage-based, priced per connected
social account” without public tiers. Because it is a hosted, closed service —
there is no self-hosting, Docker option, or source repository — you are also
accepting a dependency on Zernio’s uptime; the public status page
is worth bookmarking before you build on it.
Who it’s for
Reach for Zernio if you are a developer or building an AI agent and want multi-platform posting without maintaining a pile of per-network integrations, and you are comfortable on a hosted SaaS with not-yet-public limits. If you would rather run your own scheduler and own the data, a self-hosted app is the better fit — see our write-up of Postiz, which solves a similar problem from the opposite direction. More developer tooling lives in the Developer tools section.
Zernio is young, but the design — one key, one request shape, every network and the ad platforms behind it — is genuinely useful if it holds up. See the API and its limits for yourself at zernio.com and decide whether it fits your stack.
