Can AI replace PostFast?

01What it costs

Checked Aug 14, 2026 · source: postfa.st.

Hidden costs: Hard caps apply to social accounts, workspaces, users, queued posts, drafts and X accounts; going past them requires a higher plan. Prices are EUR and USD totals move with exchange rates.

02Could AI build it for you?

The core job: Compose posts into a slot-based queue, publish them on schedule to the open-API networks via per-network adapters, and expose the same queue over MCP so a coding agent can schedule too.

What a working version needs:

• OAuth/API access per social network
• always-on box for the scheduler
• database
• media storage
• ffmpeg and somewhere to run transcodes for anything past text and images

Same shape as the other schedulers · the code is a weekend, the nine platform approvals and the video pipeline behind it are not.

03What you'd give up

Connecting Instagram or TikTok here is one click because the OAuth app behind it already passed Meta App Review, TikTok's audit, and Google's business verification, a process that takes weeks and that a solo builder often cannot qualify for at all. Video is the other half of the bill: each platform enforces its own container, codec, aspect ratio, duration, and size rules, so a working scheduler runs a real transcode pipeline with async jobs, retries, and honest failure states rather than one hopeful upload call. The subscription also absorbs the work that never finishes: tokens expiring, per-platform media rules changing, endpoints deprecating on someone else's schedule. Above that sits the part a rebuild would not reach anyway, which is cross-account analytics and follower history, approvals and workspaces for running client accounts, and an API plus MCP server so your agent schedules through it instead of you maintaining a poster forever.

04Free and cheaper alternatives

05The build prompt

Paste this into an AI coding tool (such as Claude, ChatGPT, Lovable or Replit) to build your own version.

Build me a personal social scheduler my coding agent can drive, to replace PostFast. Requirements:

- Node + Express + better-sqlite3 on my always-on box. Two interfaces over one core:
  a localhost page (compose box, media attach, queue by send time) and a stdio MCP
  server via @modelcontextprotocol/sdk with create_post, list_posts, and delete_post,
  so Claude Code can schedule without me opening the page.
- Open-API networks only: Bluesky (app password via @atproto/api), Mastodon (access
  token), Telegram channel (bot token). One adapter file per network, creds in .env.
- For the gated platforms (Instagram, TikTok, YouTube, Facebook, Threads, LinkedIn,
  Pinterest, Google Business Profile) do not fight the APIs: at send time push me an
  ntfy.sh alert with the caption and media path and I post by hand. The README says
  plainly that these need reviewed developer apps, not more code.
- Slot-based queue: posting times per weekday in my timezone, new posts take the next
  free slot or pin to an exact datetime; one post fans out to several networks with
  per-network text.
- A node-cron tick every minute sends what is due, marks the row sending before it
  calls anything so a crash never double-posts, retries 3 times with backoff, then
  records sent or failed with the error.
- Media in media/ beside the database, images resized per network with sharp. Video:
  accept MP4 only and check duration, aspect ratio, and size against each network's
  limits at attach time, rejecting with the limit in the message rather than fixing it.
- A history page of the last 100 sends linking to the live posts.
- Binds to localhost only. No accounts, no telemetry, everything stays on my box.
- Out of scope: video transcoding, analytics, approval workflows, and workspaces.
  Do not build auth.
- README: Bluesky app password, Mastodon token, Telegram bot token, wiring the MCP
  server into Claude Code, and a warning that social APIs drift and need patching.

06Open-source starting points

• Postiz: AGPL social scheduler, self-hostable, covers the DIY core for the open-API networks.