> For the complete documentation index, see [llms.txt](https://docs.bitsafe.finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.bitsafe.finance/beth/concepts-and-reference/proof-of-reserve.md). # Proof of Reserve ### What this page helps you do Use this page to: * Check BETH backing from public data. * Understand how the reserve total can be calculated independently from Ethereum data. * Identify what the evidence proves and what it does not prove. * Stop safely when data is stale, incomplete, or inconsistent. ### The reserve claim BETH is designed as an ETH-backed asset on Canton Network. The reserve claim is that the ETH held by the Ethereum bridge contract covers circulating BETH on a 1:1 basis. Use the maintained circulating-supply source, coverage formula, and freshness policy when evaluating the 1:1 reserve claim. A Chainlink Proof of Reserve feed for BETH is in development. BitSafe will announce it when it is available. ### Check BETH backing To perform a reserve check: 1. Read the ETH balance of the Mainnet bridge contract `0xb5d425d678B10949dD0f7bB0dd0427C47451D57E`. Use your own Ethereum node or a block explorer. Record the balance and the block number. 2. Read the circulating BETH supply from the BitSafe API: ```http GET /beth/v1/total-supply ``` The response is the supply in whole BETH, as a plain decimal number with up to 10 decimal places, for example `0.01`. Record the value and the time of the request. 3. Convert the balance from wei to ETH. One ETH is 10^18 wei. 4. Compare the reserve with the supply. The reserve covers the supply when the ETH balance is equal to or larger than the BETH supply. 5. Save the balance, block number, supply value, request time, and source links with your review record. **Expected outcome:** the ETH balance is equal to or larger than the BETH supply. The reserve and the supply can differ for a short time while a deposit or a redemption is pending. In that case, the reserve is larger than the supply. The baseline is 1:1 backing. If the reserve is smaller than the supply, stop and follow the support and incident path in [Security and trust index](https://docs.bitsafe.finance/security-and-trust/). ### What this evidence proves When the inputs are complete and current, the check can show: * The ETH held by the bridge contract at the observed block. * The circulating BETH supply that the BitSafe API reports at the request time. * Whether the observed reserve amount is consistent with the fully backed claim. ### What this evidence does not prove Proof of Reserve is one control. It does not, by itself, prove: * That the reported BETH supply is correct. The BitSafe API reports the supply. For an independent read of the supply, use, for instance, the token metadata endpoint of the Digital Asset Utility registry. * Future reserve coverage. The result is valid only for its observation time and data freshness. * That redemption will complete within a specific time or at a specific cost. * That contracts, signing software, operators, APIs, or operational processes are free of defects. * That one Ethereum data provider is correct. High-assurance checks should compare independent sources. ### Handle stale, missing, or inconsistent data * Do not interpret missing data as a zero balance. * Do not treat a stale observation as current reserve evidence. * Do not compare a balance and a supply value from far apart in time. * Record the balance, block number, supply value, and request time before escalating. * Re-run the check with a second approved Ethereum data source. * Escalate through the approved support and incident path if the reserve is smaller than the supply or independent sources disagree. Use the maintained security and support references for the current freshness threshold, severity levels, contact, incident path, and retry interval. ### Technical sources * [Ethereum bridge](https://github.com/DLC-link/evm-asset-bridge) * [Digital Asset Utility registry: instrument metadata API](https://docs.digitalasset.com/api-reference/public/get-apitoken-standardv0registrars-registrymetadatav1instruments) ### Related pages * [How BETH works](/beth/how-beth-works.md) * [BETH architecture and trust boundaries](/beth/concepts-and-reference/architecture-and-trust-boundaries.md) * [BETH Attestor Network](/beth/concepts-and-reference/attestor-network-and-ethereum-signing.md) * [BETH security](/beth/concepts-and-reference/security.md) ### Next step 👉 **Put the evidence in context:** [Security and trust index](https://docs.bitsafe.finance/security-and-trust/). --- # Agent Instructions This documentation is published with GitBook. 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