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Stack0

Privacy Policy

Last updated: October 17, 2026

This Privacy Policy describes how Campbell Venture Studio, LLC, a Delaware limited liability company doing business as Stack0 ("Stack0", "we", "us", or "our"), collects, uses, shares, and protects information when you use our websites (including stack0.dev and agents.stack0.dev), our dashboards and apps, and our APIs (together, the "Service").

The Service includes these products, and others we may add:

  • Chief (Stack0 Agents): AI agents that run work for a business, such as reading and sending email, managing calendars, posting to social accounts, working in Slack, and keeping documents and tasks
  • Cloud: hosting for apps, databases, and preview environments
  • Build: an AI app builder that writes and deploys code
  • Launch: a website service that builds and runs a business's site
  • SEO and SEO Autopilot: search reports, and an AI agent that proposes site changes as pull requests
  • Studio: AI video, including AI voices
  • Analytics, Feedback, and Design
  • Developer APIs: email sending, file storage and delivery (CDN), web data (screenshots, page extraction, crawling), and video transcoding

1. Information We Collect

1.1 Account Information

When you create an account, we collect:

  • Name, email address, and sign-in details (an email code, or an identity from Google, GitHub, or Apple)
  • Organization names, team members, and their roles
  • Profile details you choose to provide

1.2 Payment Information

Stack0's own subscriptions and usage are billed through Stripe. Stripe collects and processes your payment method. We do not store full card numbers, CVVs, or bank account numbers. We keep Stripe customer and subscription identifiers, invoices, usage records, and the last four digits of a card for display.

1.3 Your Content

"Your Content" is what you and your team put into the Service or create with it. Depending on the products you use, it includes:

  • Chief: your conversations with your agents, the business profile you give during setup, documents, tasks, records, files, and what agents produce
  • Connected accounts: data from accounts you connect, such as email, calendar events, files, spreadsheets, social pages, and Slack messages (see Section 4 for Google data)
  • Build, Cloud, and Launch: source code, app data, databases, website content, domains, and deployment settings
  • SEO: the sites you add, search data for them, and the repositories you connect for SEO Autopilot
  • Studio: footage, images, scripts, voices, and the videos produced
  • Analytics and Feedback: events your sites send, and feedback, posts, and messages from your users
  • Developer APIs: emails you send (recipients, subjects, bodies, attachments, delivery events), files you store, URLs you submit for screenshots or extraction and the results, and videos you upload

1.4 Your Customers' Information

If you run your business on the Service, Your Content can include information about your own customers, such as their names, contact details, bookings, purchases, and messages. See Section 9.

1.5 Chief's Conversation Before Sign-Up

At agents.stack0.dev/start, anyone can talk with Chief about their business before creating an account. For that conversation we collect:

  • The messages you write
  • The website address you give. Chief reads public pages of that site to understand the business.
  • A one-way, salted hash of your IP address, used only to limit how many conversations and emails can come from one place. We do not store the address itself.
  • The result of a bot check by Cloudflare Turnstile, which runs before the conversation starts. Cloudflare processes that check under its own privacy policy.
  • The email address you give if you ask for your report by email

The report Chief writes is available to anyone who has its link. The link contains a long random code, and the report page shows no contact details. Conversations that never receive an email address are deleted after 30 days.

1.6 Usage, Device, and Log Data

When you use the Service, we collect:

  • Request logs: endpoint, response code, timing, request size, and the IP address of the request
  • Activity in the dashboards and apps, and error logs
  • Resource use for billing: compute, storage, bandwidth, emails sent, AI model usage, and API calls
  • Browser type, operating system, device type, and referring page

2. How We Use Information

  • Provide the Service: run your agents and apps, connect to the accounts you link, build and host code and sites, send email, store and deliver files, and produce the reports, videos, and answers you ask for
  • Billing: measure usage, apply plan credits, create invoices, and collect payment
  • Operations and security: monitor performance, fix errors, prevent abuse and fraud, enforce limits, and protect accounts
  • Communications: send service messages, such as reports you requested, alerts, security notices, billing notices, and policy changes
  • Support: answer your requests, using logs and account information
  • Product improvement: study aggregated usage to improve the Service. This does not include reading Your Content.
  • Legal: meet legal obligations, enforce our Terms of Service, and protect our rights

3. AI and Your Content

Many features use AI models. When you use them:

  • The content needed for the request, such as your messages, documents, or site pages, is sent to an AI model provider (for example Anthropic or OpenAI) to produce the answer or action
  • We use providers' business API terms, under which they do not train their models on content sent through the API
  • We do not train our own AI models on Your Content
  • We do not sell Your Content or use it for advertising
  • If you connect your own AI provider key, requests made with it go to that provider under your agreement with them

AI output can be wrong. Agents act only within the permissions you give them. See our Terms of Service for your responsibilities when agents act for you.

4. Google User Data

Chief can connect to a Google account when you choose to connect it. With your permission it can access:

  • Gmail: read messages, and send messages you or your agents send
  • Google Calendar: read and manage calendars and events
  • Google Drive and Google Sheets: read, create, and edit files and spreadsheets

How we use this data:

  • Only to provide the features you use, such as answering email, booking time, and keeping documents
  • We never sell it
  • We never use it for advertising
  • We do not use it to develop, improve, or train generalized AI or machine learning models
  • It is sent to AI model providers only as needed to perform a task you asked for, and under terms that prevent the provider from training on it
  • No person at Stack0 reads it, except with your consent, when needed for security or to investigate abuse, or when required by law

Stack0's use and transfer to any other app of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements.

You can stop access at any time by disconnecting Google in Chief's settings or by removing Stack0 in your Google Account's third-party access settings. To ask us to delete Google data we hold, contact hello@stack0.dev.

5. How We Share Information

We do not sell personal information. We share information only as follows.

5.1 Service Providers (Sub-processors)

We use these providers to run the Service:

  • Hosting and compute: Fly.io, Amazon Web Services
  • Databases: PlanetScale
  • File storage: Tigris, Amazon S3
  • Content delivery, DNS, and bot checks: Cloudflare, Amazon CloudFront
  • Payments: Stripe; Run Payments and its processors, when a business uses Chief to take card payments
  • AI models: Anthropic, OpenAI
  • AI voices: ElevenLabs
  • Search and web data: Exa, DataForSEO
  • Email delivery: Amazon SES
  • Analytics: Tinybird; PostHog on our marketing website
  • Code hosting: GitHub, when you connect a repository

These providers process information only to provide their service to us. We may update this list as the Service changes.

5.2 Accounts You Connect

When you connect an account, such as Google, Meta (Facebook and Instagram), Slack, Stripe, GitHub, or a domain registrar, information moves between the Service and that account as needed for the features you use. That provider handles the information under its own terms and privacy policy.

5.3 Legal Requirements

We may disclose information when required by law, subpoena, court order, or government request. Where permitted, we will tell you first. We may also disclose information to protect our rights, prevent fraud, or protect the safety of others.

5.4 Business Transfers

If Stack0 is involved in a merger, acquisition, financing, or sale of assets, information may transfer as part of that deal. We will tell you by email or a notice on our website before your information becomes subject to a different privacy policy.

6. Data Retention

  • Account information: kept while your account is active, and deleted within 30 days after account deletion
  • Your Content: kept until you delete it or your account is closed
  • Chief's conversation before sign-up: deleted after 30 days if no email address was given; otherwise kept until you ask us to delete it, or moved into your account if you sign up
  • Logs: request and error logs are kept for up to 90 days, and security and abuse logs for up to 12 months
  • Payment and billing records: kept for 7 years for tax and accounting

After an account is closed, Your Content is deleted within 30 days, and backups that contain it are removed within 90 days. You can ask us to export or delete your data at any time by contacting hello@stack0.dev.

7. Data Security

We protect information with measures that include:

  • Encryption in transit with TLS
  • Encryption of stored credentials and connected-account tokens
  • API keys stored as hashes and never shown in full after creation
  • Access limited by organization and role
  • Network controls that keep internal services and private addresses unreachable from customer code
  • Logging and monitoring of access to production systems

No method of transmission or storage is fully secure. If a breach affects your information, we will notify you as required by law.

8. Cookies and Tracking

  • Essential cookies: our dashboards and apps use cookies for sign-in, sessions, and security. They cannot be turned off.
  • Analytics: our marketing website uses PostHog to understand how it is used. Our apps measure usage with Stack0's own analytics.
  • Local storage: some pages keep small settings in your browser, such as the link to a conversation you started

We do not use advertising cookies, sell data to ad networks or data brokers, or track you across other sites.

9. Your Customers' Data

When you use the Service to run your business, we process your customers' information on your behalf and on your instructions. For that information, you are the controller and we are your processor (or service provider). You are responsible for having a lawful basis to collect it, for the notices and consents your customers need, including consent to receive texts or calls, and for answering their requests. We will help you answer those requests where we can. Our Terms of Service and this Privacy Policy form our data processing terms. Business customers can ask for a signed data processing agreement by contacting hello@stack0.dev.

10. International Data Transfers

The Service runs mainly in the United States. Most of our apps run on Fly.io in the US, and some services run on Amazon Web Services in the US. Content delivery networks cache files in locations around the world. If you use the Service from outside the US, your information is transferred to and processed in the US.

For transfers from the European Economic Area, the United Kingdom, or Switzerland, we rely on the Standard Contractual Clauses approved by the European Commission and the safeguards our providers offer.

11. Your Rights

11.1 Everyone

Wherever you are, you can:

  • See and update your account information
  • Disconnect any account you connected
  • Revoke API keys
  • Export your data, and delete your account and its data

11.2 European Economic Area, United Kingdom, and Switzerland

You also have the right to:

  • Get a copy of your personal data in a structured, machine-readable format
  • Correct inaccurate data
  • Ask us to delete your data
  • Restrict or object to some processing
  • Withdraw consent where we rely on it
  • Complain to your local data protection authority

We process personal data to perform our contract with you, for our legitimate interests (security, fraud prevention, and improving the Service), with your consent where we ask for it, and to meet legal obligations.

11.3 California and Other US States

Residents of California and other states with privacy laws have the right to:

  • Know what personal information we collect and how we use it
  • Ask us to correct or delete it
  • Opt out of the sale or sharing of personal information. We do not sell or share it for advertising.
  • Not be treated differently for using these rights

In the past 12 months we collected the categories of information in Section 1 for the purposes in Section 2. We have not sold personal information.

11.4 How to Use Your Rights

Contact us at hello@stack0.dev. We respond within 30 days, or sooner where the law requires. We may need to confirm your identity first. If you are a customer of a business that uses Stack0, contact that business; we will help it respond.

12. Children

The Service is for businesses and is not meant for children under 16, or under 13 in the US. We do not knowingly collect information from children. If we learn that we have, we delete it. If you believe a child has given us information, contact hello@stack0.dev.

13. Other Websites

The Service links to other websites and services. Their privacy practices are their own. Review the privacy policy of any account you connect.

14. Changes to This Policy

We may update this Privacy Policy. We will tell you about material changes at least 30 days before they take effect, by email or a notice in the Service. The date at the top of this page shows the latest version. If you keep using the Service after a change takes effect, the updated policy applies.

15. Contact

Questions about this Privacy Policy or our data practices: