Connect once. Record continuously.
Deliver events through the server API. Stable source IDs support retry deduplication; receipts are sequenced per stream.
THE VERIFIABLE RECORD LAYER FOR AI BILLING
Every usage record.
Evidence you can check.
Turn billing records between platforms, suppliers and customers into independently verifiable evidence. Connect the hosted API, issue receipts, share by permission, and verify offline.
Free during the current phase · No payment details required
USAGE RECEIPT
GENERATION 06No. 000042
GENERATION 06No. 000042
LEDGER RECORDreq_demo_0042ILLUSTRATION
- stream
- billing:demo
- generation
- 6
- pricing_expr_hash
- sha256:8c2a…f901
- self_hash
- sha256:7d4f…c208
000040000041000042
Ed25519 · Merkle · RFC 3161One record. Multiple perspectives.
01 / From a usage event to evidence you can verify offline
BUILT FOR ACCOUNTABILITY7 core checksRole-based disclosureIndependent offline verification
A SHARED BASIS FOR RECONCILIATION
Give every bill a verifiable record.
Keep your existing billing system. Open Tally receives usage events and handles receipt issuance, commitments, and evidence delivery.
One ledger. Appropriate visibility.
Public observers see hashes. Suppliers and customers inspect only the records their credentials authorize.
Let the counterparty verify.
Evidence bundles can be downloaded and verified offline. Public specifications define each check and its limits.
FROM INTEGRATION TO VERIFICATION
A clear path.
One step at a time.
Read the docs or run the no-account synthetic examples, then connect your ledger using provisioned tenant credentials.
Read the quickstart- 01
Prepare a tenant and pricing
Obtain the service URL and credentials; publish the agreed pricing expression.
- 02
Deliver real usage events
Export from your billing transaction or outbox, referencing a published pricing hash.
- 03
Wait for evidence readiness
Track acceptance, issuance, commitments, timestamps and anchoring separately.
- 04
Download and independently verify
Fetch evidence by role and inspect PASS, FAIL and SKIPPED for each check.
A CLEAR VIEW FOR EACH PARTICIPANT
See what you need. Check what matters.
Illustration only; no verification is executed here. Actual verdicts depend on the evidence bundle.
Public observer
DISCLOSURE 0101Signature validityAvailable
02Sequence continuityAvailable
03Hash-chain continuityAvailable
04Merkle inclusionAvailable
05RFC 3161 timestampAvailable
06Cost recomputationNot disclosed
07Retail itemizationNot disclosed
Supplier / auditor
DISCLOSURE 0201Signature validityAvailable
02Sequence continuityAvailable
03Hash-chain continuityAvailable
04Merkle inclusionAvailable
05RFC 3161 timestampAvailable
06Cost recomputationAvailable
07Retail itemizationNot disclosed
Customer
DISCLOSURE 0301Signature validityAvailable
02Sequence continuityAvailable
03Hash-chain continuityAvailable
04Merkle inclusionAvailable
05RFC 3161 timestampAvailable
06Cost recomputationNot disclosed
07Retail itemizationAvailable
Be precise about what evidence proves.
Open Tally verifies the integrity and consistency of signed records. It does not prove upstream model identity, absolute metering accuracy, or that every real call was captured.
START WITH SOMETHING YOU CAN CHECK