Terms of service.

Stackvoice is provided by MACHINES - WORDS (Pty) Ltd, registration number 2026/713540/07, registered at 17A Ophir Road, Plumstead, Cape Town 7801, South Africa ("we", "us"). Aaqiel Pillay is the Information Officer.

Stackvoice helps you write for Substack: an article, a Note, or a reply. It keeps your writing samples and a measured Voice File, drafts text using an AI model, and runs a style and claims check before you publish. Every draft is saved in your workspace for you to review and edit.

Stackvoice never publishes anything on your behalf. It cannot post, send, like or follow on Substack. You review each draft, you press Publish yourself, on Substack, every time.

AI drafting is provided through OpenCode Zen, which routes the request to Anthropic's Claude models. A style check and a claims-review pass are separate signals shown beside a draft, never folded into one score, and neither one verifies that a claim is factually true or that a draft sounds like you.

The optional Chrome companion is a side panel next to Substack. It can:

• Read the text you select and the empty editor you focus, only on substack.com tabs and your signed-in Stackvoice tab.
• Show you a saved, approved draft, with its claims review and voice provenance kept separate.
• Insert the exact saved revision into the empty editor you captured, after you confirm the revision, the writing surface and the destination.

It never does any of the following:

• press Publish, Post or Send
• read a cookie or store a key
• auto-schedule, auto-like or auto-follow anything

It only has permission on substack.com and your one paired Stackvoice origin.

• You must be 18 or over and using Stackvoice for your own writing or on behalf of a business you represent.
• You are responsible for what happens under your login. Keep your password private.
• A workspace may have more than one member. Each member is bound by these terms.

• A new workspace starts with 10 free AI drafts. No card is required for this. Manual writing, without AI drafting, is always free.
• Paid plans are billed monthly in advance, in US dollars, through PayPal. PayPal's own terms apply to the payment itself.
• You can cancel at any time from Settings. Cancelling stops future renewals and AI access immediately. It does not refund the current period.
• We may change list prices with 30 days' notice by email to the address on the account.

Current prices and AI-draft allowances are shown in the app before you subscribe.

You agree not to:

• use Stackvoice to impersonate someone else or to publish content you know to be false or harmful.
• attempt to read another workspace's content, or to defeat rate limits, access controls or the drafts-only handoff in the Chrome companion.
• use the companion on any site other than substack.com and your paired Stackvoice tab.
• resell Stackvoice itself as your own product.

• Everything you write here is yours: writing samples, drafts, your Voice File, workspace settings. We store them so the product works. We do not sell them or use them to train AI models.
• You can export your workspace content at any time from Settings.
• You can delete your workspace, or your account entirely, from Settings. Deleting your account removes any workspace where you are the only member. A workspace you share with others keeps its data and its other members.
• Our privacy policy says what we store, where, and for how long.

• We promise that a draft you have not edited or approved is never sent anywhere, and that the companion only ever inserts the exact saved revision you confirmed.
• We do not promise that an AI-drafted sentence is factually correct, that a clean style check means a claim is true, or that a draft sounds exactly like you. Review every draft before you publish it.
• A "Mark published" marker in Studio is self-reported by you. Stackvoice has no way to read Substack and cannot confirm a post actually went out.
• Stackvoice is provided as it is. To the extent the law allows, we exclude all other warranties.

To the extent the law allows, our total liability to you for anything arising from Stackvoice in any twelve-month period is limited to the amount you paid us in that period. We are not liable for lost profit, a reader relationship, or a published piece that turned out to contain an error you did not catch on review.

• You can delete your account at any time from Settings, or ask through support.
• We can suspend or close an account that breaks section 6, after telling you why, unless the breach must be stopped at once.

We will give 30 days' notice of a material change by email to the address on the account, and update the date shown above. Continuing to use Stackvoice after that date is acceptance of the change.

These terms are governed by the law of the Republic of South Africa. Nothing in them takes away a right you have under the consumer or data-protection law of the country you live in.