An assistant might open Chrome, retrieve comments from a JSON endpoint, and compose through Old Reddit. Calling it “browser-based” does not explain which parts will survive an access change.

Reddit’s September 30 announcements describe future transitions. They do not establish that every existing integration has already stopped working.

Five dates, different consequences

The developer announcement sets out this schedule:

• October 31, 2026: Reddit stops accepting new requests for public API access.
• November 30, 2026: the migration bounty application deadline. This is not a general registration deadline.
• January 12, 2027: API access starts closing for apps and users that have not registered or responded to Reddit’s outreach.
• March 2027: remaining public API access closes. The announcement does not specify a day in March.

There is a separate fifth date: November 13, 2026, when Reddit stops supporting RSS feeds. The infrastructure announcement points moderators toward Devvit tools for alerts, but says there is no replacement for RSS feeds outside communities they moderate.

That announcement also describes upcoming Old Reddit access restrictions: access will be limited to logged-in moderators and users who used Old Reddit within the preceding six months. Do not assign those restrictions the RSS deadline; their timing is described as the coming months.

Developers should inspect the app-registration resources. Registration does not establish that a particular external workflow has an equivalent supported replacement.

Audit the task, not just the integration name

Consider a hypothetical invoice-reminder tool: it discovers complaints, reads the thread, submits an answer, and checks that answer appeared.

Inventory those four operations:

A successful page load does not establish continued availability for background reads or post verification.

Retain source URLs, observation dates, relevant text and missing context. These remain inspectable if a feed stops, but still need checking before you act.

A practical prompt for reviewing your own inventory:

List each operation, its documented access method, and the evidence for that classification. Keep unknowns explicit. Identify what needs retesting when access changes. Do not infer continued availability from one successful operation.

Our own dependency is part of the story

Current ThreadFox reading and verification functions also use Reddit JSON endpoints, and some workflows use Old Reddit. Connected Chrome does not exempt us from Reddit’s controls. We have not validated the toolkit against future changes that have not been deployed.

Retain your research, source links and drafts. Access remains Reddit’s decision.

For founders who want help preparing that work, ThreadFox costs $49 once, plus applicable tax. It includes reusable tools and a one-product Launch Pack: a researched community plan and three tailored drafts, emailed within 24 hours after claiming in the buyer library. Claim before installation and use the pack manually. Optional tools need compatible Claude Desktop, Claude Code or Codex access, Chrome and Reddit; AI costs are separate. No ThreadFox subscription; 30-day refund. Inspect the complete sample.

Here is what we found, and what it means if you are building (or just using) an agent that posts.

Self-promotion: 12 communities say yes

Twelve out of 705 is under 2%. Add the 88 that allow it with limits and you still have only 100 communities, one in seven, where a post about your own thing is fine outside a pinned thread.

Big communities are stricter. Of the 100 largest in the set, 67 restrict self-promotion, 18 confine it to a dedicated thread, 5 allow it with limits, 10 say nothing, and none allow it plainly.

"No rule mentions promotion" is mostly a small-community category: its median size is about 87,000 members, against about 418,000 for the thread-only group. Silence is not permission. Moderators still remove what looks like spam, and Reddit's own rules apply everywhere.

Some communities add conditions on top: a minimum account age, karma earned in that community, or one named weekly thread for all promotion. An agent that skips those gets removed before a human ever reads the post.

AI content: 256 communities remove it

That is more than a third of the set. Among the 100 largest communities, 58 have a rule against AI-generated content.

The rules are rarely long. r/gaming's rule on off-topic posts ends: "No AI slop." r/Blogging asks for disclosure instead: "If you're posting AI-generated content (e.g., blog drafts, summaries), clearly disclose it in the post or comment. Approval is subject to individual assessment." r/InteriorDecorating allows it with conditions: "AI generated or AI edited content is allowed when clearly disclosed and used to help with a genuine interior decorating question, idea or visualization."

Three communities, three different answers. A generic "is AI content allowed on Reddit?" check gets all three wrong.

What an agent should do before it posts

1. Read the current rules on the day it posts. Rules change. Our index is a dated snapshot, and every page in it says when it was read.
2. Check the self-promotion verdict. If promotion belongs in a thread, the post goes in the thread, never as a standalone post.
3. Check the AI rule. If AI-generated content is removed there, don't post AI-written text there. If labels are required, label it.
4. Check account requirements such as account age and karma before writing anything.
5. Write one post for that community. Say it's yours. Don't paste the same text into ten subreddits.
6. Check the next day that the post is still up, and stop posting in communities where posts get removed.

Steps 1 to 4 are reading. They are cheap, and they are exactly what agents skip when a prompt says "post this to five relevant subreddits."

Doing the reading from an agent

We built ThreadFox Lite for this part: a free, open-source (MIT) MCP server for Claude Desktop, Claude Code, Codex or any MCP client. In Claude Code:

claude mcp add threadfox-lite -- uvx threadfox-lite

It has four read-only Reddit tools. subreddit_rules returns a community's rules with the self-promotion, AI and account-age rules flagged. find_communities finds subreddits on a topic with the same flags. account_check reports an account's age, karma and whether its recent posts are removed or hidden. post_status says whether a post is still live, removed by moderators or deleted. It never posts, votes or changes anything. Reads run in your own Chrome, signed in as you, through Microsoft's Playwright Extension, because Reddit now sends signed-out requests to a login page.

A prompt that works:

Before drafting anything, call subreddit_rules for each community on my list. Drop any community that removes AI-generated posts or only allows promotion in a thread, and tell me which rule excluded it.

More on Lite: threadfox.vip/lite.

If you also want the agent to write the post, publish it once from your own browser and recheck it the next day, the full ThreadFox kit is $49, one time.

Before building our own Reddit tools for AI agents, we wanted to know what already existed. So we read every tool registered by 13 open-source Reddit MCP servers and agent-skill collections (at least 40 GitHub stars; pure scrapers and multi-platform tools excluded), straight from source rather than their READMEs.

Between them they register 97 tools:

Reading is well covered. Five of the 13 can post. And not one tool exists to answer the question that decides whether an account survives: did that post actually go up, and is it still up?

Why "after the post" matters more than the post

An AI agent that can post but can't follow up fails in a few specific ways:

• Lost responses. The submit request times out. Did it post? An agent that retries can double-post. One that gives up may leave a live post it doesn't know about.
• Silent removals. Many communities remove posts through filters or moderators without telling you. From the author's own session the post often still looks live.
• Repeating what already failed. Without a record of removals, the agent keeps posting to a community that has already removed it twice.
• Duplicates across restarts. In-memory "already posted" checks vanish when the MCP server restarts, which in a Claude Code session is often.

The nine safeguards we checked

For every tool that can post, we checked whether the code (not the prompt) enforces each of these:

1. Keeps a record of every attempt that survives a restart
2. Refuses a second send to the same target
3. Requires publication evidence before confirming a send
4. Resolves a send whose response was lost
5. Schedules and records later removal checks
6. Stops posting to a community after removals
7. Checks community rules before posting
8. Caps how much it posts
9. Spaces out its writes

Results for the posting tools, counting only safeguards enforced in code:

Credit where it's due: jordanburke/reddit-mcp-server fetches the new post once to confirm it and spaces writes 2 seconds apart with back-off on HTTP 429. mguozhen/social-bot keeps a SQLite log of reply attempts, allows one reply per post URL and requires the reply to appear on the page. Several skills describe good behavior in their instructions, but an instruction is something the model may or may not follow; we only counted what the software enforces.

Nobody resolves a lost response, schedules removal checks or stops after removals. Those three are exactly the ones that matter at 3 a.m. when an agent is running unattended.

What we learned building the missing half

If you're building your own Reddit agent, these are the parts that took us the longest to get right:

Reserve before you send. Write the attempt to a durable ledger (SQLite is fine) before the network call, keyed by community + title/body hash. A crash between "sent" and "recorded" then shows up as a reserved-but-unresolved attempt instead of vanishing.

Treat a timeout as "unknown", never as "failed". Before sending again, look for the post: check the account's own submitted list and the community's /new listing. Wait a few minutes first, since Reddit listings lag. Only release the reservation when both checks come back empty.

Verify from Reddit's own flags, not from "it looks live to me". Your logged-in session sees your own removed posts. The post JSON carries removed_by_category and is_robot_indexable; together with the community's /new listing they tell you whether other people can actually see it.

Recheck on a schedule. We check at 1, 6, 24, 72 and 168 hours, and a removal found at any of them is recorded against that community.

Stop after repeated removals. Three unresolved removals in a community and our ledger refuses further posts there until a person looks. It's a small rule, and it's the one that protects the account most.

Be polite to the API. Space reads about 1.5 seconds apart, and after a 429 stop all Reddit calls for about 10 minutes. Retrying sooner just extends the limit.

Read the rules first, and write for the room. Requiring a rules fetch before the first post in a community catches flair requirements, self-promotion bans and required disclosure lines. It also changes what a good post looks like. A post written for r/buildinpublic isn't one for r/ClaudeAI, and the ledger refuses an identical title and body across communities.

The full audit

Every tool, every safeguard, with the file and line at the commit we read: threadfox.vip/compare. If you maintain one of these projects and think we misread something, tell us (support@threadfox.vip) and we'll correct it.

What this doesn't show: nobody, including us, has measured whether any of these setups gets more views or fewer removals. It compares what the code does, not outcomes.

About ThreadFox

ThreadFox is our answer to the gap: 26 tools for Claude Code and Codex that read rules, search, post and reply through your own logged-in Chrome, plus the ledger above. We built it from our own Reddit run, where posts from two days (Sept 20–21, 2026) drew 978,227 recorded views with no ad spend, with AI doing most of the posting and replying. It's $49 one-time: threadfox.vip. There's a free handbook sample at threadfox.vip/preview.