Post to Mastodon via API: connect once, post with one call (2026)

How Mastodon posting works

Mastodon is a federated network: each server (instance) runs the same open REST API. To post you create an application + access token in Preferences › Development on your instance, then POST to /api/v1/statuses. PostWire does this for you across any instance — you just supply the instance URL and token once.

No central approval, no OAuth audit. Connect and post immediately.

Smart Distribute: CamelCase hashtags and alt text

PostWire's Smart Distribute turns a single prompt (plus optional media) into the best native post for every network — never the same text everywhere, which every algorithm penalizes. For Mastodon it writes CamelCase hashtags (for screen-reader accessibility) and alt text for any image, matching Fediverse norms, while it simultaneously reframes the same idea for TikTok, YouTube, X, LinkedIn and the rest. AI generation is included free on every plan (you pay for brands, not per post) and is one MCP tool (generate_posts) or one REST call (POST /api/generate).

1. Connect your Mastodon account

Create the token at your-instance › Preferences › Development › New application with the write:statuses scope. PostWire stores it encrypted and uses it only to post. You can also connect from the dashboard without writing code.

curl -X POST https://postwire.io/api/connect \
  -H "Authorization: Bearer $POSTWIRE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"platform":"mastodon","credentials":{"instance_url":"https://mastodon.social","access_token":"your_access_token"}}'

2. Post with one REST call

Once connected, publishing is a single request. Add more networks by putting more strings in platforms — same payload, one call.

curl -X POST https://postwire.io/api/post \
  -H "Authorization: Bearer $POSTWIRE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"platforms":["mastodon"],"text":"Hello from PostWire 👋"}'

Response: {"results":[{"ok":true,"platform":"mastodon", ...}]}

3. Or let an AI agent post it (MCP)

PostWire ships a first-class MCP server — not docs-only. Add it to any MCP client (Claude, Cursor, your own agent):

{
  "mcpServers": {
    "postwire": {
      "command": "npx",
      "args": ["-y", "postwire-mcp"],
      "env": { "POSTWIRE_API_KEY": "pw_live_xxx" }
    }
  }
}

Then the agent just calls the tool — no HTTP plumbing:

{
  "name": "post_to_social",
  "arguments": { "platforms": ["mastodon"], "text": "Shipped today 🚀" }
}

Mastodon via API: build it yourself vs PostWire

Pricing: flat per brand

Running 50 brands on Ayrshare costs roughly $779 — and its MCP is docs-only, so an agent can't actually post. See PostWire vs Ayrshare.

FAQ

Can I post to Mastodon via API?

Yes. Every Mastodon instance exposes the same REST API. You create an access token in Preferences > Development and POST to /api/v1/statuses. PostWire wraps this behind one endpoint and one MCP tool and works across any instance.

How do I get a Mastodon access token?

On your instance go to Preferences > Development > New application, give it the write:statuses scope, and copy the access token. Provide PostWire your instance URL and the token; PostWire stores it encrypted.

Is Mastodon live on PostWire right now?

Yes. Mastodon is live today on any instance, with no app review, alongside Bluesky, Telegram, and Discord.

How does an AI agent post to Mastodon?

PostWire ships an MCP server (postwire-mcp). The agent calls post_to_social with platforms set to mastodon and the text. PostWire posts the status to your connected instance and returns the result.

How much does it cost to post to Mastodon?

Free plan: 1 brand, 30 posts/month. Paid plans are flat per brand: Starter $9, Pro $29, Agency $99 for 50 brands, Scale $299.