Letterly is an AI social media agent that turns every newsletter edition into a week of posts in the writer’s own voice, for solo newsletter creators.
It watches a newsletter’s RSS feed. When a new edition goes out, it writes posts for X, LinkedIn, Threads and Facebook from it, spreads them across the week and publishes them. The writer sets it up once and goes back to writing.
Founded
November 2024
Based in
Portugal
Price
$29 a month
Posts to
X, LinkedIn, Threads, Facebook
What Letterly does
Seven parts, all in the one $29 plan.
The agent
The agent checks your newsletter’s RSS feed every 30 minutes. When a new edition appears it writes a set of posts from it, ten for X and five for LinkedIn by default, and schedules them across the following days. It publishes them on its own or waits for your approval, depending on the autonomy level you choose.
Convert
Convert turns one edition into posts on demand, from a link or from pasted text. It is for back issues, or for an edition you want to share before the agent picks it up.
Voice personas
A persona is built from posts you have already published. You paste a link to your profile, pick the posts that sound most like you, and Letterly writes against them, so an X post reads like your X posts and a LinkedIn post like your LinkedIn posts.
The composer
The composer writes new posts from scratch, with no newsletter behind them, in the persona you pick. It can push forward an idea from your recent posts or give three different angles on one topic, in five shapes from one-liners to short stories.
Calendar and content
Every post lands in one calendar and one content list, where you can edit, reschedule, approve or reject it. Nothing the agent writes is hidden from you.
Images
Letterly pulls the images out of each edition so posts can carry them. It can also generate images in your brand colours and logo, up to three a day.
Analytics
The dashboard tracks follower growth on every connected platform, how each post performed, and clicks on the tracked links that point back to your newsletter.
What makes Letterly different
Most tools in this space are schedulers: you write the post and they publish it. Letterly starts one step earlier. Competitor details are from their own pricing pages, checked on 25 September 2026.
It starts from the newsletter, not from a blank post
Buffer, Typefully and Hypefury are built around posts you write, with AI to help you draft them. Letterly reads each edition from your RSS feed and writes the week’s posts from it, so there is no draft to start and nothing to copy and paste.
X, LinkedIn, Threads and Facebook on one plan
Letterly posts to all four. Hypefury stopped supporting X in 2026, and Typefully does not post to Facebook. Buffer covers all four but charges for each channel separately.
One flat price, paid month to month
Letterly is $29 a month with every feature and all four platforms included, billed monthly with no contract. Typefully’s Creator plan is $99 a year with annual billing only, and Buffer’s paid plans start at $5 a month per channel, so the price grows with every account you connect.
Three levels of autonomy, and an emergency stop
On Manual you approve every post. On Light Touch posts go out on schedule unless you step in during an approval window of 1 to 24 hours, and on Full Auto the agent publishes without asking. The emergency stop halts it at once, and nothing queued slips through.
The ideas come from your newsletter, the voice from your posts
Each post takes its idea from the edition and its tone from posts you have already published, with a separate persona for X, LinkedIn and Facebook. Every platform keeps its own voice instead of one generic AI voice.
Built by a newsletter writer who uses it
Vicente Évora built Letterly for his own newsletter, which has 1,157 subscribers and no paid promotion behind it. 546 of them arrived in the three months to 23 September 2026, while Letterly was posting every edition for him.
Who uses Letterly
People who already write a newsletter every week or two and want it to reach more readers on social.
Solo newsletter creators with 500 to 5,000 subscribers who publish every week
Writers on beehiiv, Substack, Ghost, Kit (formerly ConvertKit) or Mailchimp, or any platform with an RSS feed
Founders and indie hackers who write a build-in-public newsletter
Newsletter writers who post on X and LinkedIn, then stop when the week gets busy
Writers who want to be on four platforms without paying for each channel
The team behind Letterly
Vicente Évora
Founder
Vicente writes Notes to 10K MRR, a weekly build-in-public newsletter on beehiiv, alongside university and a part-time job. Every edition went out on time, and the social posts that were supposed to follow it never did.
He came up with Letterly on 26 November 2024 to write those posts for him, and shipped the first version around the turn of the year, in January 2025. The agent that runs on its own from an RSS feed followed in 2026.
Letterly is built and run by one person. Vicente builds the product, answers support and reads every email himself.
Setup takes about ten minutes: sign up, paste your newsletter’s RSS feed, connect the accounts you want to post to and add a persona. The free plan includes one full agent run on your latest edition, so you see real posts before you pay.
When an edition goes out
Letterly checks your feed every 30 minutes, so a new edition is picked up within about half an hour of publishing. Its posts are written straight away and spread over the following days, up to three a day on X and two on LinkedIn by default.
What you hear from Letterly
You get an email when a run finishes, when your queue of posts is running low, and if a post fails to publish. Everything else is in your calendar.
Who you talk to
You deal with the founder directly. Write to vicente@letterly.pro and Vicente replies within 24 hours.
Billing
Payments go through Polar, which acts as merchant of record and handles VAT. You cancel from your settings whenever you want, with no contract to end.
Key facts
Key facts about Letterly
Company name
Letterly
Type
Software as a service: an AI social media agent for newsletter creators
Founded
November 2024. First version released in January 2025.
An agent that turns each newsletter edition into scheduled social posts in the writer’s own voice
Pricing
$29 a month, one plan with every feature. Seven-day free trial. A free plan includes one full agent run.
Contract terms
Month to month. No annual contract. Cancel from your settings at any time.
Services
Newsletter-to-social agent, on-demand conversion, voice personas, AI post composer, content calendar, image extraction and generation, social analytics
Platforms
X, LinkedIn, Threads and Facebook
Newsletter sources
Any RSS feed, including beehiiv, Substack, Ghost, Kit and Mailchimp
Letterly is an AI social media agent for newsletter creators. It turns each new edition into posts for X, LinkedIn, Threads and Facebook, written in the writer’s own voice, then schedules and publishes them.
Is Letterly an alternative to Buffer, Typefully or Hypefury?
For newsletter writers, yes. Those tools schedule posts you write, while Letterly writes the posts from your newsletter and then schedules and publishes them, for one monthly price across four platforms. If you mainly want to schedule posts you write yourself, a scheduler is the simpler fit.
Which newsletter platforms does Letterly work with?
Any newsletter with an RSS feed. That includes beehiiv, Substack, Ghost, Kit (formerly ConvertKit) and Mailchimp.
Does Letterly post without my approval?
Only on Full Auto. On Manual you approve every post, and on Light Touch you get an approval window of 1 to 24 hours before each one goes out.
Will the posts sound like me?
Letterly writes against posts you have already published, with a persona for each platform. You can edit any post before it goes out.
How much does Letterly cost?
$29 a month for everything, billed monthly, after a seven-day free trial. There is also a free plan that includes one full agent run.
Who is behind Letterly?
Letterly was founded in November 2024 by Vicente Évora, a newsletter writer based in Portugal. He builds and runs it on his own and answers support email himself.
Can I cancel at any time?
Yes. There is no contract, and you cancel from your settings whenever you want.
