Postiz vs Zernio (2026): App vs API for AI Agents

Short answer

Pick Zernio if you are building posting, inboxes or ads into your own product and want each customer's accounts under your app, billed per account with two free. Pick Postiz if you want a ready-made calendar for your team, with an API and MCP for your own accounts. At 30 accounts, Postiz costs $49 a month and Zernio $108.

Prices checked on November 2, 2026, monthly billing, USD. Pricing pages: Postiz, Zernio.

PostDelegate makes a social media scheduler, so we have a stake. We link every source so you can check. PostDelegate is built on the open-source Postiz project (AGPL-3.0). See /licenses.

At a glance

Postiz compared with Zernio
Feature	Postiz	Zernio
What it is	Scheduler: hosted cloud or self-hosted open sourcesource	Social media API for developerssource
Hosting	Postiz Cloud, or self-host it on your own serversource	Hosted APIsource
Pricing model	Flat monthly plans, tiered by number of channelssource	Per connected account per month, cheaper per account at volumesource
Plans	Standard $29 (5 channels), Team $39 (10), Pro $49 (30), Ultimate $99 (100)source	Accounts 1–2 free, 3–10 $6/month each, 11–100 $3/month each, 101+ $1/month eachsource
Free option	No free cloud plan; the self-hosted code is free to runsource	First 2 accounts free, no credit cardsource
Trial	7-day trial; a payment method is required to start itsource	Not listed
Networks	30 listed, including Instagram, Facebook, LinkedIn, TikTok, X, YouTube, Threads, Pinterest, Reddit, Bluesky and Mastodonsource	Social, messaging, blog and ads platforms through one API, including X, Instagram, TikTok, LinkedIn, Facebook, YouTube, Threads, Reddit, Pinterest and Blueskysource
API	Public API, CLI and webhooks on every plansource	The product is the API: posting, analytics, comments, messaging, ads and webhookssource
MCP for AI agents	Hosted MCP server on every plansource	MCP server, documented at docs.zernio.com/mcpsource
AI writing	AI copilot on every plan, with monthly AI image, video and clipping allowances by plansource	Not listed
Teams and approvals	Unlimited team members on Team, Pro and Ultimate; none on Standardsource	Not listed
License	AGPL-3.0 (open source)source	Not listed

Cost at 3, 10 and 30 accounts

Zernio bills every connected account on a sliding scale; Postiz sells channel bundles. Zernio is cheaper up to eight accounts and Postiz from nine. Zernio also passes X's API charges through on top, which these totals leave out.

Monthly cost of Postiz and Zernio by number of connected accounts
Accounts	Postiz, per month	Zernio, per month
3	$29 (Standard, 5 channels)source	$6 (2 free + 1 × $6)source
10	$39 (Team, 10 channels)source	$48 (2 free + 8 × $6)source
30	$49 (Pro, 30 channels)source	$108 (2 free + 8 × $6 + 20 × $3)source

Monthly billing, before tax. Each figure is worked out from the plan prices on the linked pricing page.

App or API: the real difference

Most comparisons line these two up feature by feature, which hides the point. Postiz is a product people log into: a calendar, a composer, team members and client groups, with an API for when you want to script it. Zernio is plumbing for developers: one REST API that posts, reads analytics, answers DMs and comments, runs ads and even sends SMS or WhatsApp messages, with a dashboard on the side. Four questions usually settle it:

Will your own customers connect their accounts inside your product? That is Zernio's home ground.
Will people on your team plan and review posts in a calendar? That is what Postiz is for.
Do you just want Claude or ChatGPT to post to your own accounts? Either works; both run a hosted MCP server.
Do you need DMs, ads or messaging from the same integration? Zernio covers them; Postiz is about publishing.

MCP, webhooks and SDKs

Zernio's MCP server lives at mcp.zernio.com. You sign in from Claude, ChatGPT, Cursor or another client, or an unattended agent sends an API key. It offers 20 core tools for common jobs plus one generated tool for each API endpoint. Zernio publishes official SDKs for Node.js, Python, Go, Ruby, Java, PHP, .NET and Rust, and lets each user register up to 50 webhook endpoints for events such as a post publishing, a DM arriving or an account disconnecting.

Postiz includes a hosted MCP server, a CLI, the public API and webhooks on every Cloud plan. Webhook allowances grow with the plan, from 2 on Standard to 10,000 on Ultimate. Its docs cap the create-post endpoint at 100 requests an hour on Cloud, and one request can schedule several posts.

Building a product on top

Zernio's docs walk through exactly this. Each of your customers gets a profile tagged with your own customer ID, their accounts connect into it, and webhooks come back carrying that ID so you can route them. Profiles are free; you pay for connected accounts. You can also connect through your own developer app on each network, so the consent screen shows your brand and the rate limits are your app's.

Postiz has two features that look similar but serve a different job. Client invite links let a client connect their accounts into your Postiz workspace, which suits agencies. OAuth lets other Postiz users authorise your app to act on their Postiz account, which suits integrations. Neither turns Postiz into a white-label backend for thousands of end users.

Where Zernio wins

Two accounts free with the full API, and $6 for three.
A multi-tenant model built for SaaS products, with your own apps on each network.
Inbox, comments, ads, WhatsApp and SMS from the same API.
Official SDKs in eight languages.

Where Postiz wins

A finished app with a calendar, a composer and unlimited team members from $39.
Lower totals from nine accounts up: $39 a month for 10 channels, $49 for 30.
Open-source code under AGPL-3.0, with the option to self-host.
An AI copilot plus monthly AI image, video and clipping allowances.

What to check before you choose

Who connects the accounts: you and your team, or your customers inside your product.
Whether anyone non-technical needs to schedule posts day to day.
Your X volume, since Zernio bills X's API usage at cost on top.
Which networks you need. Zernio covers social, messaging, blogs and ads; Postiz adds community and publishing destinations such as Mastodon, Lemmy, Medium and DEV.to.

Where PostDelegate fits

PostDelegate sits on the app side of this split: a hosted scheduler built on Postiz, with a REST API, webhooks and an MCP server on every plan for the accounts you connect yourself. It is not a multi-tenant API for your customers' accounts. Plans start at $19 after a 7-day trial with no card, and Instagram, Facebook, Threads, TikTok, LinkedIn, Pinterest and X are still pending approval.

What it is: Hosted scheduler built on Postiz, run by Nasida Apps LLCsource
Price: 7-day free trial, no card, then from $19/month. 3 accounts: $19 (Starter, 5 channels) · 10 accounts: $29 (Team, 10 channels) · 30 accounts: $39 (Pro, 30 channels). Pricing
Live today: 16 networks: YouTube, Bluesky, Telegram, Discord, Slack, Tumblr, Lemmy, Nostr, Twitch, Kick, Dribbble, DEV.to, Medium, WordPress, Hashnode, Listmonk (email). Platform status
Pending approval: Instagram, Facebook, Threads, TikTok, LinkedIn, Pinterest and X. These cannot be connected yet.
API and MCP: MCP server on every plan, with sign-in (OAuth) or an API keysource
AI: Bring your own: AI runs on your own OpenAI key or the assistant you connect over MCP; PostDelegate never charges for AIsource

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FAQ

Is Zernio a scheduler?

Mostly it is an API. Zernio does have a dashboard where you can write and schedule a post, but its pricing and docs are aimed at developers, and it describes itself as built for people who can make API calls, with n8n, Make and Zapier for everyone else. Postiz is the other way round: a scheduling app first, with an API alongside.

Can my customers connect their own accounts?

With Zernio, yes: you give each customer a profile, connect their accounts into it, and can use your own app on each network so the consent screen shows your brand. Postiz is built for your own team: client invite links let clients connect accounts into your Postiz workspace, and OAuth lets other Postiz users authorise your app, but each of them needs a Postiz account.

Which has an MCP server?

Both, hosted. Zernio’s server at mcp.zernio.com accepts a sign-in or an API key and exposes 20 core tools plus one tool per API endpoint. Postiz includes its MCP server, CLI and API on every Cloud plan.

Is there a free tier?

Zernio’s first 2 connected accounts are free with no card, including the full API. Postiz Cloud has no free plan; it starts at $29 a month after a 7-day trial, though the open-source code is free to self-host.

Does Zernio charge extra for X?

Yes, on top of the account price. Zernio passes X’s own API charges through at cost with no markup, and analytics and inbox syncing for X accounts are opt-in so you control that spend. The totals on this page leave X costs out.

Postiz and Zernio are trademarks of their owners. PostDelegate is not affiliated with or endorsed by either. Last updated 2026-11-02.

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Postiz vs Zernio: scheduler app or social media API?