Privacy Policy

Depth is a Chrome extension that summarizes the page you're reading. To do that, it has to send the page text to a language model. This policy explains exactly what data Depth collects, where it goes, how long it's kept, and what you can do about it. Nothing in this policy is buried; if a section feels like it's missing, it probably isn't relevant.

The short version

Depth stores your settings, cached results, and saved deck items on your own device. When you ask for a level, the active page's text is sent to a language model — either Depth Hosted (our managed backend, the default) or a third-party provider you've configured with your own API key. Depth Hosted needs an account identifier and (if you pay) a Stripe customer ID; that's the extent of the personal data we hold. We do not sell, rent, or share your data with advertisers, data brokers, or analytics vendors.

01Who we are

"Depth," "we," and "us" refer to the developers of the Depth Chrome extension and the marketing site at depth.productivities.fyi. The extension source is published under the MIT License at github.com/zachzwy/depth. For privacy questions, contact support@productivities.fyi.

02What Depth collects, and where it goes

The table below is the complete list of data the extension handles. Each row names the data, where it is stored, why we have it, and (for anything that leaves your device) which parties see it.

Data	Stored where	Purpose	Shared with
Page text and titlein-use	RAM on your device while a level is rendering; the prompt+result pair is cached in `chrome.storage.local` for 7 days	Sent to the model provider so it can return a summary, quiz, or Socratic reply for that page	The model provider you selected — Depth Hosted (default) or the third-party provider whose API key you configured
Settings (provider, model, language, API keys)	`chrome.storage.local` on your device	Remember your configuration between sessions	Nobody. API keys are used only to authenticate your direct requests to the provider you chose; they never reach our servers
Cached results and per-page session state	`chrome.storage.local` on your device (cache 7 days, session state 24 hours)	Avoid regenerating the same level and remember which tab you were on if you close and reopen the panel	Nobody
Saved deck items (cards you explicitly save)	`chrome.storage.local` on your device	Power the in-extension flashcard deck	Nobody, unless you publish one to the community share feature (see §4)
Account identifierDepth Hosted	Our backend (Supabase, hosted in the United States) and your local extension storage	Route generation requests, enforce the daily free-tier quota, and let you sign in across devices	Supabase, our backend hosting provider. If you sign in with Google, Google sees the standard OAuth flow (email, name, profile picture)
Email addressif you sign in	Our backend (Supabase)	Convert an anonymous account to a permanent one so the account survives a reinstall	Supabase; Google identity provider during the sign-in flow
Stripe customer and subscription IDsif you pay	Our backend; Stripe	Process subscription payments and let you manage billing	Stripe. Card numbers are entered into Stripe's hosted checkout — we never see or store them
Generation request metadataDepth Hosted	Our backend (transient request logs, retained up to 30 days for abuse prevention and debugging)	Apply rate limits, debug failures, and detect abuse of the free tier	Nobody outside our backend hosting providers (Supabase, Cloudflare)
Published community summariesopt-in	Our backend; visible at `depth.productivities.fyi/community` and `/s/<slug>`	Let other users discover summaries of the same URL	The public internet. See §4 for what's published and how to delete

03Browser permissions

Chrome shows you the permissions Depth requests at install time. Here's what each one is actually used for:

activeTab & scripting — read the text of the page in the active tab when you open the panel, and inject the panel into that tab.
storage — the local settings, cache, session state, and deck described above. Nothing in chrome.storage.local is synced to your Google account.
identity — used only when you sign in with Google, to launch the OAuth flow via chrome.identity.launchWebAuthFlow.
host_permissions for arxiv.org, docs.google.com, raw.githubusercontent.com, and a few related domains — needed so the extension can read PDFs, Google Docs, and raw text files when those are the active tab.
Optional host permissions for each model-provider API endpoint (e.g. api.openai.com, api.anthropic.com) — granted by you only if you configure that provider in bring-your-own-key mode. We request the minimum host needed per provider.

04The community share feature

Community share is opt-in. Nothing is published unless you press "Share" on a level. When you do, we send to our backend:

The summary, quiz, or other level content as it was generated for you.
The URL and title of the source page so other readers can find the original.
Your account identifier, so the share is attributed to your account (no display name is shown publicly unless you've added one).

Published shares are world-readable. To remove one, open it from your account, hit "Unshare," or email support@productivities.fyi with the slug. We also accept takedown requests for shares published by others — see the DMCA page.

05Bring-your-own-key mode

In BYOK mode, the extension talks directly to the third-party provider whose key you entered. Depth Hosted is not involved — we don't see the request, the response, or the page text. Each provider has its own privacy policy and data-retention practices; we recommend reading the one for the provider you actually use:

OpenRouter, OpenAI, Anthropic, Google (Gemini), DeepSeek, Qwen (Alibaba), Groq, Mistral, xAI.
If you use Ollama on localhost, requests stay on your own machine.

Before any first-time use of a provider, model, or language, Depth shows a consent screen naming the third party your page text is about to be sent to. Changing provider, model, or language re-triggers that consent screen.

06What we do not collect

We do not run analytics, ad-tracking, fingerprinting, or session-replay code inside the extension or on the marketing site.
We do not collect your browsing history. Depth only reads a page when you open the panel on it.
We do not sell, rent, lease, or trade personal data to anyone. We do not share personal data with advertisers, data brokers, or other third parties for marketing.
We do not use the page text, summaries, quizzes, or chat turns you generate to train our own models. (BYOK providers may train on data per their own policies — read theirs.)
We do not access the page text for any purpose unrelated to the user-facing feature that produced the request (a level, a quiz, a dive turn, an explicit share).

07Children

Depth is not directed to children under 13, and we do not knowingly collect data from them. If you believe a child has created a Depth Hosted account, email support@productivities.fyi and we'll delete it.

08Security

Local data lives in chrome.storage.local and is protected by Chrome's own profile isolation. Account data on the Depth Hosted backend is stored in Supabase (encrypted at rest, accessed over TLS) with row-level security enforcing per-user isolation. Payment data is handled exclusively by Stripe under their PCI-DSS Level 1 program. No system is perfectly secure; if you discover a vulnerability, please email support@productivities.fyi before disclosing it.

09Your rights

Whether or not your jurisdiction grants them by law, you can:

Access or export your Depth Hosted data by emailing support@productivities.fyi from the email tied to the account.
Delete your account — that wipes account data, subscription records (subject to billing-record retention required by tax law), and any published community summaries you authored. Local extension data is deleted when you uninstall the extension or clear extension storage.
Correct account information by replying to the same email channel.
Opt out of Depth Hosted entirely by switching to bring-your-own-key mode in Settings; from that point on the backend sees no further requests from you.

Residents of the EEA, UK, California, and other regions with comprehensive privacy statutes have additional rights under those laws (including the right to lodge a complaint with a supervisory authority). We honor all of them on request.

10International transfers

Our backend infrastructure (Supabase, Cloudflare, Stripe) is hosted in the United States. If you use Depth from outside the U.S., personal data described above is transferred to and processed in the United States under standard contractual clauses with each sub-processor.

11Retention

Local cache and session state: 7 days for cached results, 24 hours for per-URL session state. Cleared sooner if you reset the extension or uninstall it.
Account record: until you delete the account.
Request logs: up to 30 days, then purged or aggregated.
Billing records: retained as long as required by applicable tax law (typically 7 years), after which they are deleted.
Published community summaries: until you delete them or we remove them under our content policy.

12Changes to this policy

We will update this policy when the data flows change. Material changes — anything that expands what we collect, who sees it, or how long we keep it — are announced in-extension and on the marketing site at least 14 days before they take effect. The "Effective" date at the top of this page always reflects the current version; prior versions are kept in the public Git history of the marketing-site repository.

13Contact

Questions, complaints, requests: support@productivities.fyi. We do our best to respond within five business days.