Privacy Policy

Last updated October 7, 2026

Sum is a local-first personal knowledge app made by Claro LLC, a limited liability company in Texas, USA (“we”). It runs on computers, phones and other devices you own, and your data stays on them. This policy explains what Sum and our supporting services at hippocentaur.ai do with your information, including information from the accounts and devices you choose to connect. Claro LLC is the party responsible for this policy.

The short version

• Everything Sum collects is stored on your own devices, not on our servers.
• Every connection is read-only. Sum cannot create, change or delete anything in any account you connect.
• We do not sell your data, show ads, or use your data to train AI models.
• You can revoke any connection at any time and delete everything locally.
• If you link financial accounts, we keep a record that each link exists. It does not say which bank, and it holds nothing from the account.

What Sum collects and why

Sum collects only what you choose to connect or add. Its one purpose is to show your day in one place, on your own devices, so you can reflect on it and plan from it.

• Calendars and tasks — events (titles, times, locations, descriptions, attendees) and tasks (titles, notes, due dates, completion) from the calendar and task accounts you connect.
• Health and fitness— the health and fitness types you choose from your phone's health store and from wearables you connect.
• Location — the places your phone spends time, if you allow it.
• Finances — from the bank, card, investment, retirement, and loan or mortgage accounts you link: account details (name, type and the last digits of the account number), balances, transactions, investment holdings and investment transactions, and loan and credit details.
• Things you add yourself — activity you log, photos and notes you capture, and conversations in groups you join.

Where your data is stored

Sum's background service on your own computer downloads connected data directly from each provider and saves it in your personal Sum database on that computer. Financial data is the one exception: it passes through our bank-link service on the way, as described under Financial accounts. Data captured on your phone is sent to your computer. If you have paired other devices of yours, they sync with your computer over an end-to-end encrypted connection. None of it is kept by us. Apart from financial data while it passes through, we have no ability to read it.

AI features run on your device

Sum's AI features — for example turning a voice note into text, describing a photo, or summarising your day — run entirely on your own computer or phone. They use open-weight models that Sum downloads once and then runs offline, on your hardware: currently Google's Gemma language models (the MLX community builds), NVIDIA's Parakeet speech recognition and the Silero voice-activity detector, all fetched from Hugging Face. That one-time download of model files is the only traffic to a model provider, and it carries no data of yours.

Sum does not use any cloud or third-party AI service, and it does not connect to any AI model through an aggregator, gateway or model hub. No data from your Google account or any other connected account — raw, aggregated or derived — is ever sent to Google, NVIDIA, Hugging Face or any other model provider, and none of it is used to create, train or improve any AI model, ours or anyone else's. Data your on-device models read stays on your device, is processed locally, and is never shared with the model's publisher for training or any other purpose.

How account sign-in works

Accounts are connected with OAuth 2.0, the standard sign-in mechanism providers offer to apps, so you sign in on the provider's own page and Sum never sees your password. When you connect, your browser opens the provider's sign-in page by way of our connection service at ov.hippocentaur.ai. After you approve, the provider gives that service the access keys (OAuth tokens) for your account. The service immediately encrypts them so only your own computer can open them, hands them to your computer, and keeps no copy. Your computer stores the keys in Sum's encrypted vault. Each time a key needs renewing, your computer sends the renewal request through the same service, which again passes the result straight back and stores nothing. The service never contacts a provider's data services itself, never sees your events, tasks or readings, and never writes access keys to disk or to its logs.

Financial accounts are not connected through this service. They use a separate one, described under Financial accounts.

Sharing

We do not share, transfer or disclose data from your connected accounts or devices to anyone, including AI model providers. We hold none of it. The record of bank links described under Financial accounts is not shared either.

Connected services, one by one

Everything below is optional and read-only: Sum only reads, never writes back.

Google Calendar and Google Tasks

Sum asks Google for these permissions:

• See your calendars (calendar.readonly) and view events on your calendars (calendar.events.readonly) — to list your calendars and read their events.
• View your tasks (tasks.readonly) — to read your task lists and the tasks in them.

Sum uses this data only to show your events and tasks alongside the rest of your day in its Schedule and planning views. It is stored on your computer as described above and never shared. Sum's use and transfer of information received from Google APIs to any other app adheres to the Google API Services User Data Policy, including the Limited Use requirements.

Microsoft Outlook calendar and tasks

Connected with Microsoft's OAuth 2.0 sign-in, with read-only calendar and task permissions. Microsoft also shares your name and email address so Sum can label the connection.

Apple Calendar and other published calendars

You paste a private calendar subscription link (for example an iCloud shared calendar). The link is stored encrypted on your computer, never logged, and used only to fetch that calendar.

Apple Reminders

On iPhone, with your permission, Sum reads your reminders and sends them to your computer.

Apple Health and Google Health Connect

On your phone, with your permission, Sum reads the health and fitness types you choose, including data written there by trackers such as Fitbit and other watches and scales in the Apple and Google ecosystems. Health data is never used for advertising and never shared.

Oura rings and Withings devices

Connected with each maker's OAuth 2.0 sign-in, with read-only access to your readings.

Location

On your phone, with your permission, Sum records the places you spend time so your day can include where you were. Place names are looked up on the device itself.

Financial accounts

If you choose to link a bank, card, investment, retirement, or loan or mortgage account, the link is made through Plaid. You sign in to your institution inside Plaid's own secure window; Sum never sees your username or password. Sum receives, read-only: account details (name, type and the last digits of the account number), balances, transactions, investment holdings and investment transactions, and details of loans and credit cards, such as interest rates and payment due dates. This data is stored only on your computer and used only for your own reports and analysis. Plaid's handling of your information is described in Plaid's End User Privacy Policy.

Plaid requires Sum's own credentials on every request, so requests for this data pass through our bank-link service, which we call the Secure Finance Connector, at sfc.hippocentaur.ai. It is a separate service from the connection service, with its own keys, and it is the only service of ours that financial data passes through. Today it connects to Plaid and to no other financial data provider. Your computer keeps the access key for each bank link and sends it with every request. The service adds Sum's credentials, asks Plaid, and passes Plaid's reply straight back to your computer. The access key and the reply can be read in the service's memory only for that moment. It keeps no copy of either and writes neither to disk or to its logs. When a link is first made, Plaid gives the access key to the service once. The service encrypts it so only your computer can open it and holds it in memory until your computer collects it, for at most 30 minutes. If your computer never collects it, the service ends that link at Plaid and forgets the key.

The service does keep one record: a list of the bank links that exist. For each link it holds the public network identifier of the computer that made it, the fact that the link is with Plaid, Plaid's identifier for the link, and the dates it was made, last used and ended. It does not hold the name of your bank, any account detail, balance or transaction, or any access key. We keep it so that a bank link can be used only by the computer that made it, and so we can account for the links Plaid bills us for. The record stays after a link ends, so we can account for what we were billed. Once you have removed your bank links, you can ask us to remove the entries for your computer; our backup copies expire within 30 days.

What our servers do see

We run a small number of supporting services under the hippocentaur.ai domain (Hippocentaur is the engine Sum is built on). They exist to help your devices work, not to collect data about you.

• Connection service (ov.hippocentaur.ai). Handles account sign-in as described above. Like any web server it sees your IP address, which it uses briefly to limit abuse. Its logs contain no access keys and no account content.
• Bank-link service (sfc.hippocentaur.ai). Used only if you link financial accounts. It passes requests and replies between your computer and Plaid, and keeps the record of bank links, both as described under Financial accounts. It sees your IP address, which it uses briefly to limit abuse, and your computer's public network identifier, which it checks against a list of the computers approved to link accounts. Its logs contain no access keys and no financial data.
• Device-finding and relay service (r.hippocentaur.ai). Helps your own devices find each other across networks and, when a direct connection is not possible, relays their traffic. It sees IP addresses and each device's public network identifier. Relayed traffic is end-to-end encrypted and we cannot read it. If you invite someone to a shared group while their device is offline, the service holds the encrypted invitation in memory until their device connects; it cannot read the invitation and keeps nothing on disk.
• Place-name files (g.hippocentaur.ai). Sum downloads public place-name reference files from here. The download reveals your IP address and which country file you requested, nothing about where you have been.
• This website. Our hosting provider keeps standard web server logs. The site sets no advertising or tracking cookies.

Keeping and deleting your data

Data stays in your Sum database on your devices until you delete it. You are in control of it:

• Revoke a connection in Sum. Open Connections, find the connection and click Revoke. Sum revokes its access with the provider and deletes the stored access keys.
• Revoke from the provider. You can also remove Sum's access from the provider's side, for example your Google Account's third-party connections page or, for financial accounts, my.plaid.com.
• Delete local data. Removing Sum's data folder from your devices deletes everything Sum has stored, including any connected data already downloaded.

We hold none of your account data on our servers, so there is none for us to delete on your behalf. The one record we keep is the list of bank links described under Financial accounts. Once you have removed your bank links, you can ask us to remove the entries for your computer; our backup copies expire within 30 days. If you have questions about removing data from your own devices, contact us and we will help.

Security

Access keys are stored encrypted on your computer. Connections between your devices are end-to-end encrypted. All connections to hippocentaur.ai services and to providers use HTTPS.

Children

Sum is not directed to children under 13.

Changes to this policy

If we change how Sum handles your data, we will update this page and the date at the top. If a change affects how data from a connected account is used, we will ask for your consent in the app before it takes effect.

Contact

Questions about this policy or your data: privacy@hippocentaur.ai.