Gravatar for Bitcoin. Store your avatar on-chain, use it everywhere.
BitPic is a protocol for hosting Paymail avatars on the Bitcoin blockchain. Instead of storing images on proprietary servers, BitPic stores them permanently on-chain, signed by your identity key.
- Uses Paymail addresses instead of email
- Images stored 100% on Bitcoin, not a database
- Open protocol - anyone can run a BitPic node
- Mutable - upload a new avatar and it updates everywhere
Once uploaded, reference your avatar from anywhere:
<img src="https://bitpic.net/u/yourname@example.com">Request specific sizes with the size parameter:
https://bitpic.net/u/yourname@example.com?size=128
Supported sizes: 32, 64, 128, 256, 512
Specify a fallback image for paymails without an avatar:
https://bitpic.net/u/unknown@example.com?d=https://example.com/fallback.png
BitPic uses B Protocol for file storage with a BitPic-specific prefix:
OP_0
OP_RETURN
19HxigV4QyBv3tHpQVcUEQyq1pzZVdoAut # B Protocol
[Image Binary]
image/jpeg
binary
|
18pAqbYqhzErT6Zk3a5dwxHtB9icv8jH2p # BitPic Protocol
[Paymail]
[Pubkey]
[Signature]
| Prefix | Protocol |
|---|---|
19HxigV4QyBv3tHpQVcUEQyq1pzZVdoAut |
B (file storage) |
18pAqbYqhzErT6Zk3a5dwxHtB9icv8jH2p |
BitPic (avatar binding) |
| Endpoint | Description |
|---|---|
GET /u/<paymail> |
Avatar image (embeddable) |
GET /u/<paymail>?size=128 |
Resized avatar |
GET /u/<paymail>?d=<url> |
Avatar with fallback |
GET /api/avatar/<paymail> |
Avatar metadata (JSON) |
GET /api/exists/<paymail> |
Check if avatar exists |
GET /api/feed |
Recent uploads |
POST /api/broadcast |
Broadcast transaction |
Full API documentation: bitpic.net/docs
Register a @bitpic.net paymail at bitpic.net/paymail.
Includes:
- Avatar hosting
- Payment address resolution
- Ordinals receive address
# Install
bun install
# Run frontend
bun dev
# Run backend
cd backend && go run .
# Lint
bun run lint- Frontend: Next.js 16, React 19, Tailwind CSS v4
- Backend: Go, Fiber, Redis
- Blockchain: JungleBus subscription, ARC broadcast
MIT