Social media posting APIs for AI agents
APIs and MCP servers that let an agent schedule and publish posts to X, LinkedIn, Instagram, TikTok and other networks.
4 tools, listed alphabetically. Prices and features checked 2026-10-17 on each vendor's own pages; “not verified” means we could not confirm it.
Short answer: Buffer has the only free plan here (3 channels) and includes its API and MCP server on it. Zernio (formerly Late) is free for the first 2 connected accounts and then charges per account. Postiz starts at $29/month for 5 channels and is open source (AGPL-3.0) if you want to self-host. Ayrshare starts at $149/month and bills per customer profile, which suits products posting for many end customers.
| Tool | Free tier | Entry paid price | Meter | MCP server | Open source |
|---|---|---|---|---|---|
| Ayrshare | No free plan: 28-day free trial with Launch plan access [source, checked 2026-10-17] | Premium $149/month: 1 profile; Launch $299: up to 10 profiles; Business $599: 30 profiles, then $8.99 per profile to 100 and $3.49 to 500 [source, checked 2026-10-17] | Active social profiles; one profile can connect up to 14 networks [source] | Official MCP server [source] | not verified |
| Buffer | Free: 3 channels, 10 scheduled posts per channel, 1 API key [source, checked 2026-10-17] | Essentials $5 per channel/month, Team $10 per channel/month, billed yearly (annual billing saves 20%) [source, checked 2026-10-17] | Per connected channel on paid plans [source] | MCP server included on every plan, including Free [source] | not verified |
| Postiz | No free plan: 7-day free trial on every plan (self-hosting the open-source code is free) [source, checked 2026-10-17] | Standard $29/month: 5 channels; Team $39 (10), Pro $49 (30), $99 plan (100 channels). Yearly: $23, $31, $39, $79 per month [source, checked 2026-10-17] | Connected channels per plan (5, 10, 30 or 100); unlimited posts [source] | Hosted MCP server and CLI included on every plan [source] | AGPL-3.0; self-host with Docker [source] |
| Zernio (formerly Late) | First 2 connected accounts free, no card (X accounts need a card) [source, checked 2026-10-17] | $6 per account/month for accounts 3–10, $3 for 11–100, $1 above 100; DMs: first 10,000 sent a month free, then metered [source, checked 2026-10-17] | Connected social accounts per month, tiered; X/Twitter API calls billed separately [source] | Official MCP server [source] | not verified |
| Tool | Best for | Compliance | Data retention |
|---|---|---|---|
| Ayrshare | Products that post on behalf of many end customers, where billing per customer profile fits better than per channel or seat. | not verified | not verified |
| Buffer | Individuals and small teams who want a free start and an agent that drafts into a queue they review. | not verified | not verified |
| Postiz | Agents that schedule posts across many networks for one brand or a few, with the option to self-host the open-source version. | not verified | not verified |
| Zernio (formerly Late) | Developers who want usage-based pricing per connected account with every feature on, and a free start for two accounts. | not verified | not verified |
What to check before you pick one
- Who owns the accounts: your own brand (Buffer, Postiz) or your customers' accounts inside your product (Ayrshare, Zernio)?
- How the bill grows: per channel (Buffer, Postiz plans), per connected account (Zernio) or per customer profile (Ayrshare).
- Whether X is extra: Zernio bills X/Twitter API calls separately because X charges per call.
- Human review: Buffer's MCP drafts into your queue, which helps if posts should be checked before they go out.
- Self-hosting: only Postiz publishes its code (AGPL-3.0).
FAQ
Can an AI agent post to social media by itself?
Yes, through an API or MCP server from a scheduling service. All four tools here document an MCP server, so clients such as Claude or ChatGPT can create and schedule posts. Each network's own rules on automation still apply.
Which social posting API is free?
Buffer's Free plan (3 channels, 10 scheduled posts per channel) includes the API and MCP. Zernio is free for the first 2 connected accounts. Postiz and Ayrshare offer trials (7 and 28 days), not free plans.
Is there an open-source option?
Postiz is AGPL-3.0 and can be self-hosted with Docker.
Comparisons and alternatives
Other categories: Email · Payments · Phone, SMS and voice · Browser automation · Web search and scraping