Social media APIs for AI agents, compared
The social media APIs an AI agent can publish through are Ayrshare, Blotato, Buffer, Post Bridge, Postiz, Zernio and Chirpie. All 7 have an MCP server, so they differ on what they meter and what they cover. Chirpie is the API-first option: priced per post, free to start with the API included, and listed in the Claude Connectors Directory.
Listed alphabetically, with Chirpie (ours) last. Facts checked on 28 September 2026, each linked to the vendor's own page.
| Product | Entry price | Platforms | Fits |
|---|---|---|---|
| Ayrshare | From $149/mo per client profile. No free plan. | 14, including Instagram, TikTok, Reddit and WhatsApp | Products that post on behalf of many client businesses |
| Blotato | From $29/mo for 20 accounts. API and MCP need a paid plan. | 9 | Agents that generate the content as well as publish it |
| Buffer | Free for 3 channels, then $6 per channel/mo ($5 billed yearly). | 12, including Instagram, TikTok, YouTube and Substack | Teams where people plan and approve the calendar |
| Post Bridge | $39/mo for 15 accounts, unlimited posts. API included. | 10, including TikTok, YouTube and Google Business Profile | Creators publishing video at high volume |
| Postiz | From $29/mo for 5 channels. Free to self-host (AGPL-3.0). | 34, counting blogs, Discord, Slack and Nostr | Self-hosting, and hosted use past about ten accounts |
| Zernio | First 2 accounts free, then $6 per account/mo (graduated). | 16 on its homepage, 17 in its docs | Teams that need DMs, reviews and paid ads alongside publishing |
| Chirpie | Free for 50 posts/mo, then from $9 a month. | 8 live, 4 coming soon | Agents and scripts publishing to X, Bluesky, LinkedIn, Threads, Mastodon, Instagram, Facebook or Telegram |
Figures checked against each vendor's own pages on 28 September 2026. The pricing units are not directly comparable; each comparison page works through 1, 3 and 10 accounts.
How to choose between them
Start with the unit you are billed on. It decides cost, and every product here picks a different one. A few accounts posting a lot favour per-account pricing; many accounts posting occasionally favour per-post pricing. Headline prices say little until you know which shape you are.
Then check scope. Publishing is the common part. DMs, comment moderation, paid ads and AI generation are where these products differ, and adding one later usually means changing vendor rather than changing plan.
Treat MCP support as expected, not as a feature. Every product on this list has one. What differs is how many tools it exposes, how it signs in, and whether it needs a paid plan. A large tool surface helps if you need the breadth and makes an agent harder to predict if you do not.
If X is a major channel, price it separately. X charges $0.200 for every post containing a link. Some vendors pass that through, one strips links from X posts, and one requires your own X developer credentials. That line can exceed the subscription. The X API pricing calculator gives you the number.
Questions about choosing a social media API
Which social media API should an AI agent use?
It depends on the job. To post on behalf of many client businesses, Ayrshare's profile model is built for it. To self-host, Postiz is open source. For DMs, reviews and paid ads alongside publishing, Zernio. To generate the content as well, Blotato. For high-volume video on a flat price, Post Bridge. For a calendar that people run with an agent beside it, Buffer. Chirpie covers the narrowest ground: publishing, threads, comments and analytics through an API, with a free plan.
Which of these have an MCP server?
All seven. Ayrshare's exposes 27 tools with a Bearer key, Postiz's 13, Post Bridge's 16 with OAuth, Blotato's 36, and Zernio's 496 with OAuth 2.1. Buffer's works on every plan including Free, and Chirpie hosts one at chirpie.ai/mcp and ships a local one. MCP support no longer separates these products; the pricing unit and the scope do.
Is there a free social media posting API?
Several, with different limits. Chirpie's free plan includes the API and MCP server for 50 posts a month. Buffer's free plan covers 3 channels and includes its API and MCP server. Zernio's first two accounts are free. Postiz is free to self-host. Ayrshare, Post Bridge and Blotato offer trials rather than free plans.
Why do these products' prices look so different?
Because each meters something different. Ayrshare charges per client profile, Buffer and Postiz per channel, Post Bridge per block of accounts, Zernio per account on a graduated scale, Blotato per plan with AI credits, and Chirpie per post volume. A workload that is cheap under one unit can be expensive under another, so price your own shape rather than the headline figure.
How current is this comparison?
Every competitor fact was checked against the vendor's own pricing and documentation pages on 28 September 2026, and each comparison page lists its sources with the date each was read. Prices in this category change often, so check the source before deciding, and tell us if something is out of date.
Sources
Ayrshare
- Ayrshare pricing: https://www.ayrshare.com/pricing/ (checked 28 September 2026)
- Ayrshare supported networks: https://www.ayrshare.com/docs/help-center/product/what_social_networks_are_supported (checked 28 September 2026)
- Ayrshare profiles and connected accounts: https://www.ayrshare.com/docs/help-center/product/how_many_social_accounts_can_i_connect (checked 28 September 2026)
- Ayrshare posting limits and fair use: https://www.ayrshare.com/docs/help-center/product/how_many_posts_and_api_calls_can_i_make (checked 28 September 2026)
- Ayrshare API overview (X credentials): https://www.ayrshare.com/docs/apis/overview (checked 28 September 2026)
- Ayrshare Action MCP server: https://www.ayrshare.com/docs/additional/mcp-action-server (checked 28 September 2026)
- Ayrshare MCP connection guide: https://www.ayrshare.com/docs/additional/mcp-action-connect (checked 28 September 2026)
- Ayrshare SDK packages: https://www.ayrshare.com/docs/help-center/product/do_you_have_sdk_packages_to_make_my_life_easier (checked 28 September 2026)
- Ayrshare Comments API: https://www.ayrshare.com/docs/apis/comments/overview (checked 28 September 2026)
- Ayrshare Messaging API: https://www.ayrshare.com/docs/apis/messages/overview (checked 28 September 2026)
- Ayrshare Ads API: https://www.ayrshare.com/docs/apis/ads/overview (checked 28 September 2026)
- Ayrshare HTTP errors and rate limits: https://www.ayrshare.com/docs/errors/errors-http (checked 28 September 2026)
Postiz
- Postiz pricing: https://postiz.com/pricing (checked 28 September 2026)
- Postiz cloud plans: https://docs.postiz.com/cloud/plans (checked 28 September 2026)
- Postiz cloud and self-hosted: https://docs.postiz.com/cloud/overview (checked 28 September 2026)
- Postiz supported platforms: https://docs.postiz.com/general/platforms/overview (checked 28 September 2026)
- Postiz MCP server: https://docs.postiz.com/mcp/introduction (checked 28 September 2026)
- Postiz public API: https://docs.postiz.com/public-api/introduction (checked 28 September 2026)
- Postiz create post endpoint: https://docs.postiz.com/public-api/posts/create.md (checked 28 September 2026)
- Postiz analytics: https://docs.postiz.com/general/analytics.md (checked 28 September 2026)
- Postiz agent: https://docs.postiz.com/general/agents.md (checked 28 September 2026)
- Postiz calendar: https://docs.postiz.com/general/calendar/moving-posts.md (checked 28 September 2026)
- Postiz source (AGPL-3.0): https://github.com/gitroomhq/postiz-app (checked 28 September 2026)
Zernio
- Zernio pricing: https://zernio.com/pricing (checked 28 September 2026)
- Zernio homepage: https://zernio.com/ (checked 28 September 2026)
- Zernio for agents (MCP, CLI): https://zernio.com/agents (checked 28 September 2026)
- Zernio supported platforms: https://docs.zernio.com/platforms (checked 28 September 2026)
- Zernio SDKs: https://docs.zernio.com/sdks (checked 28 September 2026)
- Zernio docs quickstart: https://docs.zernio.com (checked 28 September 2026)
- Zernio rebrand notice (Late to Zernio): https://zernio.com/rebrand (checked 28 September 2026)
Post Bridge
- Post Bridge pricing: https://www.post-bridge.com/pricing (checked 28 September 2026)
- Post Bridge for agents: https://www.post-bridge.com/agents (checked 28 September 2026)
- Post Bridge MCP server: https://www.post-bridge.com/mcp (checked 28 September 2026)
- Post Bridge API access and pricing: https://support.post-bridge.com/api/post-bridge-api-overview-access-and-pricing (checked 28 September 2026)
- Post Bridge on thread scheduling: https://support.post-bridge.com/social-media-scheduling/thread-scheduling-on-x-twitter-and-instagram-threads-current-limitations (checked 28 September 2026)
- Post Bridge API reference (OpenAPI): https://api.post-bridge.com/openapi.json (checked 28 September 2026)
- Post Bridge llms.txt: https://www.post-bridge.com/llms.txt (checked 28 September 2026)
Blotato
- Blotato pricing: https://www.blotato.com/pricing (checked 28 September 2026)
- Blotato rate card: https://www.blotato.com/pricing.md (checked 28 September 2026)
- Blotato product facts: https://www.blotato.com/ai-info (checked 28 September 2026)
- Blotato MCP server: https://help.blotato.com/start-with-an-ai-agent/mcp.md (checked 28 September 2026)
- Blotato llms.txt: https://www.blotato.com/llms.txt (checked 28 September 2026)
Buffer
- Buffer pricing: https://buffer.com/pricing (checked 28 September 2026)
- Buffer rate card: https://buffer.com/pricing.md (checked 28 September 2026)
- Buffer API introduction (GraphQL): https://developers.buffer.com/guides/introduction.md (checked 28 September 2026)
- Buffer create a text post: https://developers.buffer.com/examples/create-text-post.md (checked 28 September 2026)
- Buffer CLI and agent skill files: https://developers.buffer.com/guides/cli.html (checked 28 September 2026)
- Buffer MCP server: https://buffer.com/mcp (checked 28 September 2026)
- Buffer API limits: https://developers.buffer.com/guides/api-limits.md (checked 28 September 2026)
X API
- X API pricing: https://docs.x.com/x-api/getting-started/pricing (checked 28 September 2026)
- X API: create a post: https://docs.x.com/x-api/posts/creation-of-a-post (checked 28 September 2026)
- X API: replies and threads: https://docs.x.com/x-api/posts/manage-tweets/integrate (checked 28 September 2026)
- X OAuth 2.0 authorization code: https://docs.x.com/fundamentals/authentication/oauth-2-0/authorization-code (checked 28 September 2026)
- X API rate limits: https://docs.x.com/x-api/fundamentals/rate-limits (checked 28 September 2026)
- X tools and libraries (XDK, xurl): https://docs.x.com/tools-and-libraries (checked 28 September 2026)
- X MCP server: https://docs.x.com/tools/mcp (checked 28 September 2026)
- X developer changelog: https://docs.x.com/changelog (checked 28 September 2026)
- X API v2 endpoint index: https://docs.x.com/x-api/llms.txt (checked 28 September 2026)