Lightfern for Email - The telepathic AI writing tool
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Finish thoughts before fingers hit keys. Working directly in your inbox as a browser extension, Lightfern nails the details that make emails feel like you - nicknames, sign-offs, your tone of voice - and pulls context from past threads to finish sentences the way you would. All with zero data retention by default.
Replies
Zivy
Congrats on the launch @gastlich @mleelightfern @dougli 👏
I loved the idea of “Cursor for email,” especially the focus on personal tone and context. W
Lightfern for Email
Thanks for the feedback!
Lightfern for Email
@mleelightfern @dougli @harkirat_singh3777 Thanks for the kind words 🙇♂️
I've been using Lightfern since its Beta and I just love the context it has on my calendar and previous e-mails.. and all these details pop up just at the right time!
Lightfern for Email
@linh_s Thanks for helping us test out Lightfern! Really appreciate all the feedback
Congrats on the launch! 🚀 Love this telepathic, in‑inbox email copilot with zero data retention.
Lightfern for Email
@zeiki_yu Thank you Zeiki! Glad that this resonates with you!
Congrats on the launch. Authenticity in AI communication is a hard problem, and it’s refreshing to see it addressed head-on instead of optimizing for generic better writing.
Lightfern for Email
@kevan_williams Thanks Kevan! Really appreciate the feedback.
Lightfern for Email
@kevan_williams Thank you - really appreciate that. Authenticity is exactly the hard part we cared most about. We’re trying to build something that supports how people already communicate, rather than replacing it with a “better” but generic version. Feedback like this genuinely means a lot to us 🙏
Cursor for email analogy is perfect! I love the focus on personalisation, we are actually building a personalised product ourselves, so I'm a believer that personalisation is king in this space. How does Lightfern handle the balance between using past thread context and the user’s global writing style? Does it prioritize recent interactions, or does it build a long-term tone of voice profile?
Lightfern for Email
@valeriia_kuna Thanks Anna for the kind words! I agree - personalisation is important.
We have mechanisms to balance past thread context with the user’s global writing style. Both approaches are valid; what matters is having the most accurate, up-to-date version of the user’s style and feeding it to the AI at the right time. Context engineering is central to our product, and we’re focused on making it correct and reliable for our users.
Can't wait to see what you've been working on 👀 Fingers crossed for your product!
@gastlich Thanks for the insights, Jacek! (It’s Valeria, by the way, but no worries :) ). I love the term context engineering—it really captures the complexity of what we are all trying to achieve with personalization right now!
Fingers crossed for Lightfern's growth! Looking forward to seeing how you guys evolve this further!
Lightfern for Email
@valeriia_kuna Sorry Valeriia for the mistake. It won't happen again :)
Congrats on the launch! Positioning this as Cursor for email with deep thread context and personal tone is compelling. How does Lightfern balance pulling in rich historical context with avoiding overreach, especially so suggestions feel helpful and accurate without surfacing details that might no longer be relevant or appropriate in a given conversation?
Lightfern for Email
Interesting project. Why don’t you save the data? Is it because of GDPR?
Lightfern for Email
@mykyta_semenov_ Great question! That's more of our philosophy on security and privacy: we don't want to have access to people's personal data more than we need to.
Telepathic’ is a bold claim. But if you actually nail tone + thread context + zero retention, that’s a real unlock. Most AI writing tools optimize for sounding better. The hard problem is sounding like you.
If Lightfern can reduce cognitive load without flattening personality, that’s where it wins.
Curious how you think about long-term memory vs. situational context that balance is everything in email.