TRADITIONAL USAGE BILLING
Vendor defines the unit.
Vendor runs the meter.
Vendor produces the invoice.
Buyer receives the final number.
TRUST THE NUMBERFUSIONIFY / CEILING
Metered billing
you can recompute.
You authorize a ceiling. Ceiling publishes what counted. You only pay for output that held up.
LIVE BILLING TRACESESSION / 001
01020304050607080910111213141516171819202122232425STREAM CUT
17 ACCEPTED1 REJECTED7 NOT CHARGED
ACTUAL$0.034000
UNUSED$0.016000
PRECOMMITTED POLICYDETERMINISTIC VALIDATORPUBLISHED OUTPUTRECOMPUTABLE BILL
01 / PRECOMMITTED POLICY
01 / 04
The upper bound exists before the output.
A canonical record, a deterministic validator, and a fixed unit price define what can count.
LIVE METER / AUTHORIZEDvalidator.v1
THE PROBLEM
The problem isn't usage billing.
It's trusting the meter.
CEILING
The unit is committed before output exists.
The validator is deterministic.
The output is published.
The final arithmetic is recomputable.
THE MECHANISM
One commitment.
One verifiable path.
.001
COMMIT
Precommit unit definition, validator, unit price, maxUnits, and failure policy.
policyHash
0x2649...f123.002
AUTHORIZE
Maximum
25 × $0.002 = $0.050
payment path / x402.003
METER
17 valid
18 rejected
cut-on-first-invalid.004
SETTLE
17 × $0.002 = $0.034
unused / $0.016
actual ≤ authorized maxRECOMPUTATION
The bill is just math.
17×$0.002=$0.034
POLICY HASHMATCH
0x2649acf4fe4f9f179b61b2b717d3b58299298de37eefcc8118aaafc328c3f123OUTPUT HASHMATCH
0xc63b3f62cfe8ee0fced6f8488804b36825f42f3f251de2196bea7e8903e1f986ACCEPTED UNITSMATCH
SETTLED AMOUNTMATCH
FINALIZEDTRUE
RECOMPUTATIONPASS
◆ ON-CHAIN / MONAD TESTNET
Recorded once.
Readable by anyone.
The registry enforces accepted units within the authorized maximum and settled amount equal to accepted units multiplied by unit price.
CONTRACT
0xbd06bb4d0a50f84fec7dcd3a916605ff662e7d61↗SESSION0xc44cd0b5674ecd5543c4ecfcf18d6897b42d367da8bd1fad15e58f065b5c528b↗DEPLOYMENT TX0x81926658e403c0db914f08a2cfb4779b5634363809701feaa982653cb94bd408↗COMMIT TX0x19aa15f6021deb6c368bed2fecb63bb1e07ab69fbaaad1f9a113a82b609b2c51↗OUTCOME TX0xa6b47e9695d056ce07b4478e29af3c34550c8100b753df7b475c4c2f9cbc9227↗POLICY↓COMMIT SESSION↓PROCESS↓RECORD OUTCOME↓READBACK↓MATCH
WHY MONAD
Many sessions.
Independent state.
Parallel settlement.
A single Ceiling session could run on many chains. Monad becomes especially useful when many independent machine-payment sessions are committed and settled concurrently.
SIMULATED CONCURRENCY VISUALIZATION
sess_01SETTLEDsess_02SETTLEDsess_03SETTLEDsess_04SETTLEDsess_05SETTLEDsess_06SETTLEDsess_07SETTLEDsess_08SETTLEDsess_09SETTLEDsess_10SETTLEDsess_11SETTLEDsess_12SETTLEDMONADhigh-performance execution
x402machine payment protocol
USDCsettlement asset
PERMIT2authorization infrastructure
CEILING / LIVE DEMO
Authorize the ceiling.
Recompute the bill.
Run the deterministic demo and inspect the same arithmetic committed on Monad Testnet.