m402

Machine Payment Required -- an open protocol for machine-native payments on physical-world data networks.

Live demo: m402.vercel.app

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What is m402?

m402 extends the x402 payment standard from the web to the physical world. Where x402 enables internet-native payments between clients and servers, m402 enables autonomous systems -- self-driving cars, delivery drones, industrial robots -- to purchase real-world sensor data through instant stablecoin micropayments.

The protocol uses the HTTP 402 status code. A machine requests data, receives a payment prompt, pays in stablecoins, and gets the data back. One atomic transaction. No contracts, no subscriptions, no humans in the loop.

agent = m402.Agent(wallet="0x...machine")

data = await agent.query(
    provider="hivemapper",
    lat=-23.5505, lng=-46.6333,
    radius_m=100
)
# $0.001 | settled in <1s | memo attached

Why m402?

Autonomous systems make thousands of decisions per hour. Every time they need data -- street imagery, GPS corrections, weather conditions, vehicle telemetry -- a human currently has to negotiate a contract, manage a subscription, or provision an API key.

m402 removes the human from the payment loop.

Problem	Current State	With m402
Data access	Enterprise contracts, 3-6 week onboarding	Instant, permissionless
Payment size	$10K+ annual minimums	$0.001 per query
Settlement	Net-30 invoicing	Sub-second finality
Integration	Custom per provider	One standard, any provider
Utilization	Machines use less than 5% of purchased data	Pay only for what you query

Architecture

m402 is built on Tempo, a payment-optimized L2 incubated by Stripe and Paradigm. Tempo provides the infrastructure that general-purpose blockchains lack for high-frequency micropayments:

• Stablecoin gas -- Transaction fees paid in any stablecoin. No ETH required.
• Sub-second settlement -- Finality faster than a single Ethereum block.
• Native 32-byte memos -- Every payment carries structured metadata for automatic reconciliation.
• Dedicated payment lanes -- Blockspace reserved for payments, never competing with DeFi or memecoins.
• 100,000+ TPS -- Designed for machine-scale throughput.
• ~$0.0001 per transaction -- 100x cheaper than general L2s.

Connected Sensor Networks

Network	Data Type	Coverage	Price per Query
Hivemapper	Street-level imagery	300K+ dashcams	$0.001
DIMO	Vehicle telemetry	1M+ vehicles	$0.001
Geodnet	cm-precision GPS	13K+ stations	$0.002
WeatherXM	Hyperlocal weather	6K+ stations	$0.0005

Live Demo

The landing page at m402.vercel.app includes a working demo that executes a real transaction on Tempo Testnet (Chain ID 42431). You can:

1. Connect a MetaMask wallet
2. Claim free testnet AlphaUSD from the faucet
3. Execute a Hivemapper street query with an on-chain memo
4. View the transaction on Tempo Scout Explorer

No real funds are involved. The demo uses Tempo's testnet faucet and AlphaUSD, a testnet stablecoin.

Tech Stack

Layer	Technology
Framework	React + Vite
Wallet integration	wagmi v2, viem
Blockchain	Tempo Testnet (EVM-compatible)
Token standard	TIP-20 (ERC-20 with native memos)
Hosting	Vercel
Fonts	Instrument Serif, DM Sans, DM Mono

Local Development

git clone https://github.com/Lekha-Reddy-git-hub/m402.git
cd m402
npm install
npx vite --host

Open http://localhost:5173 in a browser with MetaMask installed.

Tempo Testnet Configuration (MetaMask)

Field	Value
Network Name	Tempo Testnet (Moderato)
RPC URL	https://rpc.moderato.tempo.xyz
Chain ID	42431
Currency Symbol	USD
Explorer	https://scout.tempo.xyz

Project Structure

m402/
  index.html          # Entry point, favicon, metadata
  vite.config.js      # Vite configuration
  package.json        # Dependencies
  src/
    main.jsx          # React root, wagmi provider setup
    App.jsx           # All UI components and page layout
    config.js         # Chain config, contract addresses, ABI

Protocol Flow

Machine                    Data Provider                  Tempo
  |                             |                           |
  |-- GET /street-data -------->|                           |
  |<-- 402 Payment Required ----|                           |
  |                             |                           |
  |-- Pay 0.001 AlphaUSD ------|-------------------------->|
  |                             |<-- Payment confirmed -----|
  |<-- Street imagery data -----|                           |
  |                             |                           |
  Total time: <1 second
  Total cost: ~$0.001 + ~$0.0001 network fee

Related

• x402 -- The internet-native payment standard that m402 extends
• Tempo -- The payment-optimized L2 powering m402
• Hivemapper -- Decentralized street-level imagery network
• DIMO -- Decentralized vehicle data network

License

MIT

Author

Srilekha Reddy -- LinkedIn | GitHub