We build an agent that posts and replies for people across social networks, so we had to answer a boring, load-bearing question before writing a line of code: on each platform, is software even allowed to post? To reply? To read? The answers are all over the map, and most of them are not what founders assume.
So we read the developer terms, pricing pages, and API docs for 38 platforms and wrote down, for each one, whether you can publish through an official API, whether you can reply to someone else’s post, and whether automation is against the rules. Here is what we found, with the sources.
The short version
Publishing is mostly a solved problem. Roughly 20 of the 38 platforms give you a clean, sanctioned API to post your own content. Replying is where it falls apart. Only two platforms, X and GitHub, let a piece of software prefill a reply to a specific post the normal way (a share/intent URL). Everywhere else, replying to a stranger is either blocked outright, gated behind approval, or possible only for content you already own.
That gap is the whole story. A scheduler that pushes your own posts out on a timer can lean entirely on APIs. Anything that engages (replies, comments, joining a conversation) runs straight into rules that were tightened hard in 2026, specifically to stop bots from doing exactly that.
What changed in 2026, and why it matters
Two moves reset the board this year. In February, X switched new developers to pay-per-use pricing: $0.015 to create a post, or $0.20 if it contains a link. It also killed the free tier for new customers. (X’s own docs). Then, around February 21, it broke the reply API on purpose: a programmatic reply is now accepted only if the original author mentions you or quote-posts you first. X said the change targets LLM-generated reply spam (X developer community). For a growth tool that wants to reply to arbitrary posts, that’s the API going dark.
Reddit went the other direction on access but priced it like enterprise software. Posting and commenting through the API is fine, but the free tier is non-commercial only, and commercial use needs a paid license reported at around $12,000 (sources disagree on whether that figure is monthly or an annual minimum, so treat the exact number as unconfirmed until you talk to Reddit directly). On top of that, the Responsible Builder Policy from November 2025 removed self-service app registration: new API access now requires a manual application and a two-to-four week wait.
None of this is a crackdown on automation as a concept. Read the terms closely and they’re consistent: publish your own stuff, fine. Spray replies at strangers, not fine. The platforms that got stricter got stricter about the second thing.
The map, by lane
We sorted every platform by how you’d actually reach it. “API” means a sanctioned endpoint, “intent” means a share URL a human clicks to confirm, and “none / extension” means there’s no official write path at all, so the only option is a browser acting as you (which carries real terms-of-service risk and has to stay low-volume and human-approved).
| Platform | Publish | Reply to any post | Automation stance |
|---|---|---|---|
| X (Twitter) | API (pay-per-use) | Intent URL only (API reply gated since Feb 2026) | Allowed; anti-spam reply gate |
| Threads | API (free, 250/day) | Yes, API reply to any post | Allowed |
| YouTube | API | Yes, comment API | OK if not spam/repetitive |
| Mastodon | API | Yes | Allowed; bot flag + per-instance rules |
| Bluesky | API | Yes | Allowed, no bot-flag requirement |
| Discord / Slack / Telegram | API (bot) | Yes | Bots are first-class |
| API (commercial = paid license) | Yes, with subreddit rules | Allowed w/ approval; commercial needs license | |
| API (partner-gated) | No, own/managed content only | API OK; scraping & bots banned | |
| API (own account) | No cold reply | Own-account only, approval-gated | |
| Facebook (Pages) | API (owned Pages) | Owned content only | Owned Pages allowed |
| TikTok | API (unaudited = private) | No public comment write | Approval-gated; unaudited forced private |
| API | No comment write | OK on Standard tier | |
| Medium | Effectively closed | Never existed | Authoring API shut to new tokens |
| GitHub | API | Yes (issues/discussions) | Allowed with human-in-the-loop |
A representative slice of the 38 we checked. The full table, covering Farcaster, Nostr, Lemmy, VK, Tumblr, Twitch, Kick, WhatsApp, LINE, Weibo, Xiaohongshu, WordPress, Ghost, Dev.to, Hashnode, Substack, Quora, Behance, Product Hunt, and daily.dev, lives in our open-source repo.
Three things that surprised us
Threads is the quiet winner for replies.While X was locking its reply API, Meta shipped a free Threads API that lets you reply to any post, capped at 250 a day. No per-reply fee, no invitation requirement. For a tool that engages in conversations, that’s the most generous position of any large network right now.
TikTok will let you post. To nobody.If your app hasn’t passed TikTok’s audit, every post the API creates is forced to SELF_ONLY (private), and you’re capped at five posting users per day. The owner has to open the app and make each post public by hand. It technically “has a publishing API,” and it’s technically useless until you’re audited.
Medium is a ghost.There’s no way to get a new API token; that door closed around 2023. So a platform people still think of as developer-friendly is, for automation purposes, closed. If you see a tool that claims to auto-publish to Medium, it’s almost certainly driving a browser, not an API.
What this means if you’re choosing a tool
Match the tool to the lane. If all you need is to schedule your own posts, an API-only scheduler is enough and there are good open-source ones. If you want something that replies and engages, ask a blunt question: how does it reply on platforms with no reply API? There are only two honest answers. It uses X and Threads and the handful of open networks where replying is allowed. Or it drives a browser extension for the rest, slowly and with a human watching.
We landed on both. The agent uses official APIs everywhere they exist, and a browser extension only where there’s no other path, kept deliberately low-volume because the whole point of reading these terms was to not get anyone banned. That’s the subject of the next post.
Sources for every claim here are the platforms’ own developer docs and terms, collected in our public platform-capability research. Figures were current as of July 2026; API terms change often, so check the primary source before you build against it.