Supported Channels

Each social media provider in Postmill declares its supported feature set through a capability matrix. This matrix is the single source of truth for what each provider can do — the composer UI, admin settings, preflight validation, and workflow logic all gate on these values.

The canonical source is PROVIDER_CAPABILITIES in libraries/providers/kernel/src/domains/social-capabilities.ts.

Capability Column Descriptions

Column	Description
`analytics`	Provider supports fetching analytics data (profile/follower metrics, post engagement)
`comments`	Provider supports fetching and replying to platform comments via `ISocialMediaComments`
`firstComment`	Supports auto-posting a first comment immediately after a successful publish
`poll`	Supports poll-style posts with options and duration
`video`	Supports video media attachments
`carousel`	Supports multi-image carousel posts
`altText`	Supports alt text descriptions on image attachments
`maxMedia`	Maximum number of media attachments per post (0 = no media support)
`linkPreview`	Supports link preview / link-card rendering
`refreshToken`	Supports OAuth refresh token rotation
`watchlist`	Supports competitor account probing (public metric collection for watched accounts)

Full Capability Matrix

Provider	analytics	comments	firstComment	poll	video	carousel	altText	maxMedia	linkPreview	refreshToken	watchlist
X	true	true	true	true	true	false	false	4	true	true	true
LinkedIn	true	true	true	true	true	true	false	20	false	true	false
LinkedIn Page	true	true	true	true	true	true	false	20	false	true	false
Reddit	true	true	true	false	true	false	false	1	false	true	false
Instagram	true	true	true	false	true	true	false	10	false	true	true
Instagram Standalone	true	true	true	false	true	true	false	10	false	true	true
Facebook	true	true	true	false	true	false	false	10	false	true	false
Threads	true	true	true	false	true	true	false	10	false	true	false
YouTube	true	true	false	false	true	false	false	1	false	true	true
Google My Business	true	false	false	false	false	false	false	1	false	true	false
TikTok	true	true	false	false	true	false	false	1	false	true	true
Pinterest	true	false	false	false	true	false	false	5	false	true	false
Dribbble	true	false	false	false	false	false	false	1	false	true	false
Discord	true	true	true	false	false	false	false	10	false	true	false
Slack	false	true	true	false	false	false	true	10	false	false	false
Kick	false	false	true	false	false	false	false	0	false	false	false
Twitch	false	false	true	false	false	false	false	0	false	true	false
Mastodon	true	true	true	false	true	false	true	4	false	false	false
Bluesky	true	true	true	false	true	false	true	4	false	false	false
Lemmy	false	false	true	false	false	false	false	1	false	false	false
Farcaster	false	false	true	false	false	false	false	4	false	false	false
Telegram	true	true	true	false	true	false	false	10	false	false	false
Nostr	false	false	true	false	false	false	false	0	false	false	false
VK	false	false	true	false	true	false	false	10	false	false	false
Medium	false	true	false	false	false	false	false	0	false	false	false
Dev.to	false	true	false	false	false	false	false	0	false	false	false
Hashnode	false	true	false	false	false	false	false	0	false	false	false
WordPress	false	true	false	false	true	false	false	10	false	false	false
ListMonk	false	false	false	false	false	false	false	0	false	false	false
Moltbook	false	false	true	false	false	false	false	0	false	false	false
Whop	false	false	true	false	false	false	false	0	false	false	false
Skool	false	false	true	false	false	false	false	10	false	false	false
MeWe	false	false	false	false	true	false	false	10	false	false	false
Tumblr	false	false	false	false	true	false	true	10	false	true	false
Pixelfed	false	false	true	false	false	false	true	10	false	false	false
PeerTube	false	false	true	false	true	false	false	1	false	false	false
GoToSocial	true	true	true	false	true	false	true	4	false	false	false
Akkoma	true	true	true	false	true	false	true	4	false	false	false
Friendica	true	true	true	false	true	false	true	4	false	false	false
Misskey	true	true	true	false	true	false	true	16	false	false	false
Sharkey	true	true	true	false	true	false	true	16	false	false	false
LINE	true	false	false	false	true	false	false	4	false	false	false
Matrix	false	false	false	false	true	false	true	10	false	false	false
Discourse	false	true	true	false	true	false	true	10	false	false	false
Odysee	false	false	false	false	true	false	false	1	false	false	false

Summary

poll — Only 3 providers support polls: X, LinkedIn, and LinkedIn Page.

carousel — 5 providers support carousel posts: LinkedIn, LinkedIn Page, Instagram, Instagram Standalone, and Threads.

altText — 13 providers support alt text on images: Slack, Mastodon, Bluesky, Tumblr, Pixelfed, GoToSocial, Akkoma, Friendica, Misskey, Sharkey, Matrix, and Discourse.

analytics — 23 providers support analytics data collection: X, LinkedIn, LinkedIn Page, Instagram, Instagram Standalone, Facebook, Threads, YouTube, Google My Business, TikTok, Pinterest, Dribbble, Reddit, Discord, Mastodon, Bluesky, Telegram, GoToSocial, Akkoma, Friendica, Misskey, Sharkey, and LINE.

watchlist — 5 providers support competitor account probing: X, Instagram, Instagram Standalone, YouTube, and TikTok.

linkPreview — Only X supports link preview / link-card rendering.

comments — 25 providers support fetching and replying to platform comments.

firstComment — 30 providers support auto-posting a first comment after publish.

refreshToken — 16 providers support OAuth refresh token rotation.

Channels Postmill cannot support

Some platforms are requested often but have no usable publishing API — for Postmill or for any competitor. This list is kept current so the absence is a documented decision, not an oversight:

Minds — no third-party OAuth app registration or documented publishing API; the OAuth server is first-party-only (hardcoded clients), and posting exists only through an unofficial, undocumented session API.
Trovo — the API reads data, sends chat messages, and edits live-stream settings (title/category); there is no endpoint to publish posts, clips, or videos.
DLive — the GraphQL API exposes only chat, stream-settings, and moderation writes, and developer-app registration is a manual, application-only process.
Viber — broadcast requires an explicit recipient list (max 300 IDs) and Viber provides no API to enumerate a bot's subscribers, so a bot channel cannot reach its own audience.
Gab, Truth Social, Gettr, Parler, Rumble, Locals, BeReal, Lemon8 — no public write API at all.
Firefish — the project was discontinued; use the Sharkey channel (same Misskey API lineage) for Firefish-lineage instances.

Short-link providers

Postmill also includes a separate capability system for short-link providers. Each short-link provider declares support for custom domains and click analytics. The canonical source is the adapter classes in libraries/providers/<id>/src/v1/.

Provider	Custom Domain	Click Analytics	Notes
Bitly	✓	✓	Branded domains via `group_guid`
TinyURL	✓	—	Custom alias support
T.LY	✓	✓	Referral tracking
Short.io	✓	✓	iOS/Android deep links
Rebrandly	✓	✓	Workspaces, tags
Dub.co	✓	✓	Link-level tags
Cutt.ly	—	✓
Tiny.cc	—	✓
is.gd	—	—
v.gd	—	—
BL.INK	✓	✓	Enterprise analytics
T2M	✓	✓	Geo-targeting
Linkly	✓	✓	Retargeting pixels
Lnkify	✓	✓	Self-hostable (optional instance URL); GraphQL API
Replug	✓	—	Retargeting pixels
Switchy	✓	—	QR codes
PixelMe	✓	—	Conversion pixels
Sniply	✓	—	CTA overlays
Ow.ly	—	—	Ow.ly requires a Hootsuite token and is not create/stats-capable in this release.
CleanURI	—	—	Link monitoring

customDomain — 14 of 20 providers support branded/custom short domains.

clickAnalytics — 11 of 20 providers expose click-count retrieval for the analytics dashboard: Bitly, BL.INK, Cutt.ly, Dub.co, Linkly, Lnkify, Rebrandly, Short.io, T2M, Tiny.cc, T.LY.

Supported Channels ​

Capability Column Descriptions ​

Full Capability Matrix ​

Summary ​

Channels Postmill cannot support ​

Short-link providers ​