Meet Pebble Index 01 - External Memory For Your Brain

Catch your best ideas before they slip through your fingers

Do you ever have flashes of insight or an idea worth remembering? This happens to me 5-10 times every day. If I don’t write down the thought immediately, it slips out of my mind. Worst of all, I remember that I’ve forgotten something and spend the next 10 minutes trying to remember what it is. So I invented external memory for my brain.

Introducing Pebble Index 01 - a small ring with a button and microphone. Hold the button, whisper your thought, and it’s sent to your phone. It’s added to your notes, set as a reminder, or saved for later review.

Index 01 is designed to become muscle memory, since it’s always with you. It’s private by design (no recording until you press the button) and requires no internet connection or paid subscription. It’s as small as a wedding band and comes in 3 colours. It’s made from durable stainless steel and is water-resistant. Like all Pebble products, it’s extremely customizable and built with open source software.

Here’s the best part: the battery lasts for years. You never need to charge it.

Pre-order today for $75. After worldwide shipping begins in March 2026, the price will go up to $99.

#Design

Now that I’ve worn my Index 01 for several months, I can safely say that it has changed my life - just like with Pebble, I couldn’t go back to a world without this. There are so many situations each day where my hands are full (while biking or driving, washing dishes, wrangling my kids, etc) and I need to remember something. A random sampling of my recent recordings:

• Set a timer for 3pm to go pick up the kids
• Remind me to phone the pharmacy at 11am
• Peter is coming by tomorrow at 11:30am, add that to my calendar
• Jerry recommends reading Breakneck
• Mark wants a Black/Red PT2

Before, I would take my phone out of my pocket to jot these down, but I couldn’t always do that (eg, while bicycling). I also wanted to start using my phone less, especially in front of my kids.

Initially, we experimented by building this as an app on Pebble, since it has a mic and I’m always wearing one. But, I realized quickly that this was suboptimal - it required me to use my other hand to press the button to start recording (lift-to-wake gestures and wake-words are too unreliable). This was tough to use while bicycling or carrying stuff.

Then a genius electrical engineer friend of mine came up with an idea to fit everything into a tiny ring. It is the perfect form factor! Honestly, I’m still amazed that it all fits.

The design needed to satisfy several critical conditions:

1. Must work reliably 100% of the time. If it didn’t work or failed to record a thought, I knew I would take it off and revert back to my old habit of just forgetting things.
2. It had to have a physical press-button, with a satisfying click-feel. I want to know for sure if the button is pressed and my thought is captured.
3. Long battery life - every time you take something off to charge, there’s a chance you’ll forget to put it back on.
4. Must be privacy-preserving. These are your inner thoughts. All recordings must be processed and stored on your phone. Only record when the button is pressed.
5. It had to be as small as a wedding band. Since it’s worn on the index finger, if it were too large or bulky, it would hit your phone while you held it in your hand.
6. Water resistance - must be able to wash hands, shower, and get wet.

We’ve been working on this for a while, testing new versions and making tweaks. We’re really excited to get this out into the world.

Here are a few of my favourite things about Index 01:

• It does one thing really well - it helps me remember things.
• It’s discreet. It's not distracting. It doesn't take you out of the moment.
• There’s no AI friend persona and it’s not always recording.
• It’s inexpensive. We hope you try it and see if you like it as well!

#Key Details

• Available in 3 colours and 8 sizes
  • Colours: polished silver, polished gold, and matte black
  • US ring sizes: 6, 7, 8, 9, 10, 11, 12, 13
  • You can pre-order now and pick your size/colour later before your ring ships.
• Cost and availability: Pre-order price is $75, rises to $99 later. Ships worldwide, beginning in March.
• Works with iPhone and Android: We overcame Apple’s best efforts to make life terrible for 3rd party accessory makers and have Index 01 working well on iOS and Android.
• Extremely private and secure: Your thoughts are processed by open source speech-to-text (STT) and AI models locally on your phone. You can read the code and see exactly how it works - our Pebble mobile app is open source. Higher-quality STT is available through an optional cloud service.
• No charging: The battery lasts for up to years of average use. After the end of its life, send your ring back to us for recycling.
• On-ring storage: Recording works even if your phone is out of range. Up to 5 minutes of audio can be stored on-ring, then synced later.
• No speaker or vibrating motor: This is an input device only. There is an RGB LED, but it’s rarely used (to save battery life and to reduce distraction).
• Works great with Pebble or other smartwatches: After recording, the thought will appear on your watch, and you can check that it’s correct. You can ask questions like ‘What’s the weather today?’ and see the answer on your watch.
• Raw audio playback: Very helpful if STT doesn’t work perfectly due to wind or loud background noises.
• Actions: While the primary task is remembering things for you, you can also ask it to do things like ’Send a Beeper message to my wife - running late’ or answer simple questions that could be answered by searching the web. You can configure button clicks to control your music - I love using this to play/pause or skip tracks. You can also configure where to save your notes and reminders (I have it set to add to Notion).
• Customizable and hackable: Configure single/double button clicks to control whatever you want (take a photo, turn on lights, Tasker, etc). Add your own voice actions via MCP. Or route the audio recordings directly to your own app or server!
• 99+ languages: Speech to text and local LLM support over 99 languages! Naturally, the quality of each may vary.

#Future Plans

Let me be very clear - Index 01 is designed at its core to be a device that helps you remember things. We want it to be 100% reliable at its primary task. But we’re leaving the side door open for folks to customize, build new interactions and actions.

Here’s how I’m thinking about it - a single click-hold + voice input will be routed to the primary memory processing path. Double-click-hold + voice input would be routed to a more general purpose voice agent (think ChatGPT with web search). Responses from the agent would be presented on Pebble (eg ‘What’s the weather tomorrow?’, ‘When’s the next northbound Caltrain?’) or other smartwatches (as a notification). Maybe this could even be an input for something like ChatGPT Voice Mode, enabling you to hear the AI response from your earbuds.

The built in actions, set reminder, create note, alarms, etc, are actually MCPs - basically mini apps that AI agents know how to operate. They run locally in WASM within the Pebble mobile app (no cloud MCP server required). Basically any MCP server can be used with the system, so intrepid folks may have fun adding various actions like Beeper, Google Calendar, weather, etc that already offer MCPs.

Not everything will be available at launch, but this is the direction we are working towards. There will be 3 ways to customize your Index 01:

1. Trigger actions via button clicks - configure a single or double click to do things like take a photo, control your Home Assistant smart home, Tasker function, unlock your car. This will work better on Android since iOS Shortcuts doesn’t have an open API.
2. Trigger actions via voice input - write an MCP to do….basically anything? This is pretty open ended.
3. Route your voice recordings and/or transcriptions to your own webhook - or skip our AI processing entirely and send every recording to your own app or webapp.

### FAQ

How does it work?

People usually wear it on the index finger. Inside the ring is a button, a microphone, a Bluetooth chip, memory, and a battery that lasts for years. Click the button with your thumb, talk into the mic, and it records to internal memory. When your phone is in range, the recording is streamed to the Pebble app. It’s converted to text on-device, then processed by an on-device large language model (LLM) which selects an action to take (create note, add to reminders, etc).

When do I pick my size?

You’ll be able to pick your ring size and color after placing a pre-order. If you have a 3D printer, you can print our CAD designs to try on. We’re also planning a sizing kit. You can view the measurements of the inner diameter of each ring size.

How long does the battery last?

Roughly 12 to 15 hours of recording. On average, I use it 10-20 times per day to record 3-6 second thoughts. That’s up to 2 years of usage.

Is it secure and private?

Yes, extremely. The connection between ring and phone is encrypted. Recordings are processed locally on your phone in the open-source Pebble app. The app works offline (no internet connection) and does not require a cloud service. An optional cloud storage system for backing up recordings is available. Our plan is for this to be optionally encrypted, but we haven’t built it yet.

Is a paid subscription required?

No.

What kind of battery is inside?

Index 01 uses silver-oxide batteries.

Why can’t it be recharged?

We considered this but decided not to for several reasons:

1. You’d probably lose the charger before the battery runs out!
2. Adding charge circuitry and including a charger would make the product larger and more expensive.
3. You send it back to us to recycle.

Wait, it’s single use?

Yes. We know this sounds a bit odd, but in this particular circumstance we believe it’s the best solution to the given set of constraints. Other smart rings like Oura cost $250+ and need to be charged every few days. We didn’t want to build a device like that. Before the battery runs out, the Pebble app notifies and asks if you’d like to order another ring.

Is it always listening?

No. It only records while the button is pressed. It’s not designed to record your whole life, or meetings.

What if the speech-to-text processing misses a word or something?

You can always listen to the each recording in the app.

Why no touchpad?

We experimented with a touchpad, but found it too easy to accidentally swipe and press. Also, nothing beats the feedback of a real gosh darn pressable button.

Is there a speaker or vibrating motor?

No. The button has a great click-feel to indicate when you are pressing.

Does it do health tracking like Oura?

Nope

How durable and water-resistant is it?

It’s primarily made from stainless steel 316, with a liquid silicone rubber (LSR) button. It’s water-resistant to 1 meter. You can wash your hands, do dishes, and shower with it on, but we don’t recommend swimming with it.

Does it work with iPhone and Android?

Yes

I love customizing and hacking on my devices. What could I do with Index 01?

Lots of stuff! Control things with the buttons. Route raw audio or transcribed text directly to your own app via webhook. Use MCPs (also run locally on-device! No cloud server required) to add more actions.

Is this an AI friend thingy or always-recording device?

No.

How far along is development?

We’ve been working on this in the background to watch development. It helps that our Pebble Time 2 partner factory is also building Index 01! We’re currently in the DVT stage, testing pre-production samples. We’ll start a wider alpha test in January with a lot more people. Here’s some shots from the pre-production assembly line: