The product
What does v8 do?
You type a rough request in Claude Code or Codex and press Ctrl + G. v8 rewrites it in place as a short, outcome-first brief grounded in your repository: real file paths, your actual test command, and questions only when they matter. You review it and press Enter.
Does it work in Codex?
Yes, with the same key. The brief is written for Codex to act rather than ask. Codex is supported but not yet measured in our benchmark. See In Codex.
Is there a Claude Code plugin?
Yes: /v8:prompt <request> ships inside the package. It shows you the advanced prompt and waits for your choice before Claude acts. See the plugin.
Does v8 run commands or change my files?
No. It reads a few facts about the repository with git and writes text into the agent's input box. Your agent receives it only after you press Enter.
What is "v8 Hone"?
The name of v8's prompt compiler, the part on our service that writes the advanced prompt (model id hone-1). v8-prompt improve --json also reports its build, such as c2026.10.37, so you can tell which version wrote a prompt.
Results and cost
Does it make my agent better?
It makes the agent start in the right place. On tasks graded by hidden tests, Claude Code with Sonnet took 9 to 42% fewer turns with v8's brief, while the share of tasks solved did not clearly change (−6 to +2 points). When a request leaves out a value only you know, answering v8's question helped most: on 12 held-out tasks of this kind, Claude Code with Sonnet solved 50% with the answer and 17% without it. The benchmark shows every study, wins and losses.
Does it cost my agent more?
A little. The brief is longer than your request, so each agent run costs a bit more: 3 to 24% higher per run with Sonnet in our studies. Your coding agent's own subscription or API costs are separate from v8.
Does it work in other languages?
Yes. In 12 other languages (144 translated tasks), Claude Code with Haiku solved 92% with v8's brief and 89% from the raw request, a difference within noise. The brief tells the agent to answer in your language.
What if my request is already clear?
Then v8 leaves it as written and adds at most what the repository confirms, such as the test command. If your text comes back unchanged, it is not counted. See Clear requests.
Accounts and terminals
Do I need an account?
No. The free plan works without one: 10 advanced prompts a week, up to 3 a day, per terminal. You need an account for Pro or a Team seat.
What counts as a terminal?
A v8 installation, identified by a random key in ~/.v8-prompt in your user folder. Every terminal window you open under the same user on a computer shares that key, so they count as one terminal. Another computer, or another user on the same computer, is another terminal.
Can I use v8 on several computers?
Yes. With Pro, link each one with v8-prompt login and they share one weekly allowance of 350. On the free plan, each computer has its own 10 a week.
Can I use it in scripts or CI?
Yes, through v8-prompt improve, within your allowance. Reselling, sharing an account and getting around limits are not allowed. See From scripts and the Terms.
Billing and teams
Who handles payment?
Our order process is conducted by our online reseller Paddle.com. Paddle.com is the Merchant of Record for all our orders and handles taxes, invoices and customer service inquiries about payments. Your invoices are on the Billing page.
Can I cancel or get a refund?
Cancel anytime from your account; Pro stays until the end of the period you paid for. A full refund is available within 14 days of your first payment or an annual renewal; monthly renewals are not covered. See the refund policy.
Can my team admins see my prompts?
No. Team owners and admins see each member's usage counts, how many terminals they connected and when they were last active. Never prompt text, file names or code.
Your data
Does v8 send my code?
No file contents leave your computer. v8 sends your text and a pack of names and commands (file paths, function and class names, your test command, recent commit subjects), capped at 4 KB. v8-prompt context show prints exactly what would be sent. See What leaves your computer.
Are my prompts stored?
No. Prompt text and repository context are processed in memory and never stored on our servers, and our AI provider does not use them for model training. Undo copies and remembered answers stay on your computer.
How do I delete my data?
On the Account page you can download everything we store about you and delete your account. On your computer, v8-prompt forget --all clears remembered answers, and deleting ~/.v8-prompt removes everything v8 keeps there.
Is v8 open source?
No. The CLI is published on the npm registry and as a direct download with a published SHA-256 checksum, so you can check that what you install is what we released.