ForthWrite drafts Gmail and Outlook replies in your own voice for accounting, advisory and lending firms. Free plan; paid plans from $24/mo.
Researched and fact-checked by Bartu Cavusoglu · Updated October 26, 2026
ForthWrite is software and consulting for professional services firms, with a focus on accounting and tax firms, advisors and RIAs, and lenders and brokers. The software drafts email replies inside Gmail and Microsoft Outlook, using a voice profile built from the user's own sent mail rather than a generic house style.
The stated principle is that ForthWrite drafts and a person sends, so judgment and signature stay with the user. The company also says it is not an archive and does not give compliance advice. It is operated by Aesir Labs, LLC d/b/a ForthWrite and was founded by Curtis Boortz, a former lending underwriter.
The software runs in the mailbox a team already uses. A Chrome extension handles Gmail, and an add-in handles Outlook on the web. ForthWrite reads the thread being viewed, sends it to the selected AI provider, and returns a draft in the compose box. The site says thread content is not stored on its servers once the draft is returned.
Voice matching comes from the user's sent emails, and the profile refreshes about every 50 captured emails. When writing, the system retrieves the most relevant past replies as examples. The consulting side follows four steps: a free 30-minute diagnostic, a paid audit of two to four weeks, a roadmap, and implementation with written SOPs.
On the drafting side, ForthWrite offers voice matching, recipient-aware tone, and intent-aware drafting that treats follow-ups, intros and status updates differently. Pro adds auto-draft so replies are waiting when Gmail opens, batch drafting for clearing many threads at once, a custom persona prompt, retrieval of past emails, and voice dictation.
Prompt Lab provides version control, A/B testing and AI-optimized prompts, and performance analytics show an improvement curve. Teams adds a shared persona, a shared prompt library, a team dashboard covering drafts, acceptance rate, voice match and intent mix, and a review record of what was drafted, what changed and which model was used.
ForthWrite is software and consulting for professional services firms. The software drafts email replies inside Gmail and Outlook in the user's own voice. A person always reviews and sends the draft.
Free is $0 with 10 drafts per week. Pro is $24/mo billed annually or $29/mo billed monthly. Teams starts at $59/seat/mo billed annually or $79/seat/mo monthly, and Enterprise is custom.
Yes. Pro has a 14-day free trial and Teams has a 30-day trial. There is also a Free plan with no credit card required, and a 60-day guarantee on voice quality.
It is aimed at accounting and tax firms, advisors and RIAs, and lenders and brokers. Individuals who write a lot of client email can use Free or Pro, and firms can use Teams.
It works in Gmail and Outlook on the web, through a Chrome extension and an Outlook add-in. It can also be added as a connector in Claude. Paid plans can use an optional API key from OpenAI, Anthropic, Google or xAI.
No. The company states that ForthWrite drafts and a person sends. In Claude, drafts come back as text and ForthWrite never sends.
The site says thread content is sent to the selected AI provider and is not stored on ForthWrite servers after the draft is returned. Writing-style data is scoped to the user's account and not used to train a shared or third-party model.
No. Paid plans include AI by default. An optional Bring Your Own Key toggle gives about 17% off for users who already have a key and want to pay the provider directly.