Mastodon APIthrough Siar.

At a glance

Account needed: An account on any Mastodon server. Pass the server URL when connecting.

Media rules

What Siar can do on Mastodon

Siar can create comments and replies up to 500 characters, and import the comments people leave on your posts.

Publish a post

Put Mastodon's payload under data.MASTODON and list MASTODON in socialAccountTypes. Add other networks to the same request to post to all of them at once.

curl -X POST "https://api.siaran.my/api/v1/post" \
  -H "x-api-key: $SIAR_API_KEY" \
  -H "content-type: application/json" \
  -d '{
    "teamId": "TEAM_ID",
    "title": "Mastodon post",
    "postDate": "2026-11-02T09:00:00.000Z",
    "status": "SCHEDULED",
    "socialAccountTypes": [
      "MASTODON"
    ],
    "data": {
      "MASTODON": {
        "text": "Hello from Siar",
        "uploadIds": [
          "UPLOAD_ID"
        ],
        "thumbnail": "string"
      }
    }
  }'

Mastodon fields

• text string nullable
• uploadIds string[] nullable
• thumbnail string nullable
• privacy string nullable
  One of: PUBLIC UNLISTED PRIVATE DIRECT
• spoiler string nullable

Daily caps

See pricing for monthly quotas. Enterprise uses the Business caps unless agreed otherwise.

Connecting a Mastodon account

Siar sends the user to the network's consent page and stores the tokens it gets back, refreshing them before they expire. Use POST /social-account/connect from your own UI, or send your customer a hosted link from POST /social-account/create-portal-link; see connecting accounts.

Permissions requested

Siar requests only these scopes at connect time:

• read
• write

Mastodon-specific operations

These exist for Mastodon only and live under /misc/mastodon.

When Mastodon says no

Siar relays Mastodon's error code and message verbatim on the post, next to a status you can act on. Open the Mastodon error reference.