01 Build
Build anything with auto-rails
Create anything with build. Letterpress-1 is fine-tuned to write brand-ready copy and maintain brand visuals automatically.
Built for teams that grow with git
Meet Letterpress-1
Letterpress-1 is the world’s first coding agent, harness and IDE for growth engineering
Forward-thinking companies build on Letter
Letterpress-1 is a new type of coding experience designed for growth.
Letterpress-1 is designed for teams using git: autonomously fix website issues and build growth strategies via pull requests.
Plan · this week
Four things for letter.dev
- Install the Visitors script
- Warm up three mailers
- A sequence for this week’s visitors
- Fix 6 issues on 20 pages
Run the planEdit
Letterpress-1 ships with three modes.
Build reactively and proactively, eliminating issues and building common strategies.
02 Plan
Pick a goal and get a build plan
Letterpress-1 will find growth strategies to build directly into your repository without requiring additional tools.
03 Fix
Find what’s broken and fix
Easily dispatch pull requests to fix common issues across your marketing site.
Letterpress-1 has pre-built primitives that solve common growth problems.
Proofs
Simulations
Benchmarks
Agentic Conviction
Install Proofs for AI agents, then comparison pages and ranking targets. 3 things start right away.
Replaces G2 and Trustpilot
Phantoms
Kernels
Letterbases
GEO / SEO
Comparison pages, the eight thin pages written to depth, author bios on the blog.
Replaces Semrush, Sanity and Profound
Visitors
Mailers
Inbound Conversion
Natively install de-anonymization and outbound sequences.
Build a pricing page (/pricing). 1 thing starts right away.
Replaces RB2B and Instantly
Letterpress-1 uses frontier models and fine-tuned small models to produce stunning results.
When compared to Codex, Letterpress-1 generates more tasteful change. The same prompt on the same site, both runs unedited: drag to see the difference.
Prompt · letter.devProduce a landing page for marketing our product specifically to YC companies.
‹›
Letterpress-1Built in letter.dev’s own design: its type, its shape print, its buttons. It names the batch and the real primitives a YC team would start with.
CodexA clean template in a look that isn’t the site’s: a new orange accent, a stock diagram, and copy that would fit any growth tool.
Letterpress-1 is available in six different surfaces optimized for growth.
Letter platform
Build, Plan and Fix in the app, with every site, change and plan in one place.
SR
Sam Rivera
@Letter I want more engineering leaders finding us. What should we do?
1 reply
Letter APP
Here are the highest-impact moves for acme.dev:
1. Add a /for/platform-teams page
Speak to the teams who’d run you: the API, the limits, real examples.
2. Expand the 6 thin docs pages/docs/webhooks, /docs/limits and 4 more are too short to answer from.
3. Answer /compare/segment
Two competitors rank for it; you have nothing there.
Want me to kick off any of these?
Letter Slack app
Mention @Letter in any channel; reports land where your team already talks.
~/website
$ letterpress
› add a page comparing us with Rippling for teams of 5 to 50
reading the site · planning the page
building in a sandbox
reviewing the change · fixed what the review found
changed 3 files · app/compare/rippling/page.tsx
✓ pull request opened · preview is up
› put our customer quote under the table
building on the same pull request
Letterpress CLI
Run letterpress in your site’s folder and ask in plain words.
Website portal
Every preview carries a panel: what changed on the page, and a box to ask for more.
Letterpress App
Letterpress-1 on its own, outside the browser.
claude · ~/letter-dev
› what should we fix first on letter.dev?
⏺ letter · list_suggested_fixes
No Article or BlogPosting structured data on an article
/blog/ai-content-tool-evaluation-criteria-for-marketing-agencies
⏺ letter · fix_site_observations
✓ pull request opened on letterstory/letter-dev
Your own agent
Claude Code, Codex or any agent with MCP gets the same tools the app is built on.
3f9a1c07e2b84d6a9c51e0b7d42f8a16.preview.letter.dev
Built-in preview links for every change
Each change comes back as a live preview of your own site, before anything merges.
letter.dev
BIIbarra Real Nova ▾−84pt ▾+
Meet Letterpress-1 for F26.
Letterpress-1 is the world’s first coding agent, harness and IDE for growth engineering
Book demo$ npm i -g @letterstory/letterpress
Forward-thinking companies build on Letter
LetterEdit×
1 changeone pull request
1. Meet Letterpress-1 for F26.
Set in Ibarra Real Nova at 84ptMake Pull Request
A screenshot of this view goes with it
Edit text directly and create pull requests
Press ⌘L on your site or a preview, change the words where you see them, and it goes into a pull request.
SR
Sam Rivera
@Letter I want more engineering leaders finding us. What should we do?
1 reply
Letter APP
Here are the highest-impact moves for acme.dev:
1. Add a /for/platform-teams page
Speak to the teams who’d run you: the API, the limits, real examples.
2. Expand the 6 thin docs pages/docs/webhooks, /docs/limits and 4 more are too short to answer from.
3. Answer /compare/segment
Two competitors rank for it; you have nothing there.
Want me to kick off any of these?
Ask in Slack
Mention @Letter in any channel; the pull request comes back in the thread.
~/website
$ letterpress
› add a page comparing us with Rippling for teams of 5 to 50
reading the site · planning the page
building in a sandbox
reviewing the change · fixed what the review found
changed 3 files · app/compare/rippling/page.tsx
✓ pull request opened · preview is up
› put our customer quote under the table
building on the same pull request
Or from your terminal
Run letterpress in your site’s folder and ask in plain words.
Nothing lands until you say
A preview, a pull request, or merged once its checks pass. You choose.
Try engineering tools for growth today.
Install Letterpress-1 on your repository in less than 5 minutes.