covenants.md

title	categories	excerpt	primary_sources	optech_mentions	see_also
Covenants	Scripts and Addresses Soft Forks	**Covenants** are a category of proposed changes to Bitcoin's consensus rules that would allow a script to prevent an authorized spender from spending to certain other scripts.	title link Enhancing Bitcoin transactions with covenants https://fc17.ifca.ai/bitcoin/papers/bitcoin17-final28.pdf title link BIP119 OP_CHECKTEMPLATEVERIFY proposal https://github.com/bitcoin/bips/blob/master/bip-0119.mediawiki	title url Scaling Bitcoin Tokyo 2018, Script Roundtable: OP_CHECKSIGFROMSTACK /en/newsletters/2018/10/09/#discussion-the-evolution-of-bitcoin-script title url New proposed opcode: OP_CHECKOUTPUTSHASHVERIFY /en/newsletters/2019/05/29/#proposed-new-opcode-for-transaction-output-commitments title url CoreDev.tech discussion: potential script changes /en/newsletters/2019/06/12/#potential-script-changes title url Bitcoin vaults without covenants /en/newsletters/2019/08/14#bitcoin-vaults-without-covenants title url OP_CHECKOUTPUTSHASHVERIFY renamed OP_CHECKTEMPLATEVERIFY and updated /en/newsletters/2019/12/04/#op-checktemplateverify-ctv title url Suggested changes to OP_CHECKTEMPLATEVERIFY proposal /en/newsletters/2019/12/18/#proposed-changes-to-bip-ctv title url 2019 year-in-review: OP_CHECKTEMPLATEVERIFY /en/newsletters/2019/12/28/#ctv title url OP_CHECKTEMPLATEVERIFY workshop report /en/newsletters/2020/02/12/#op-checktemplateverify-ctv-workshop title url Vault prototype using pre-signed transactions /en/newsletters/2020/04/22/#vaults-prototype title url Demo implementation of a multisig vaults covenant prototype /en/newsletters/2020/04/29/#multiparty-vault-architecture title url Discussion about how Simplicity could be used for covenants /en/newsletters/2020/08/05/#bip-taproot title url Replicating the `OP_CSFS` covenant-enabling opcode with `OP_CAT` and schnorr signatures /en/newsletters/2021/02/03/#replicating-op-checksigfromstack-with-bip340-and-op-cat title url OP_TAPLEAF_UPDATE_VERIFY opcode proposed with a taproot-native covenant design /en/newsletters/2021/09/15/#covenant-opcode-proposal title url Proposal for composable `OP_TX` opcode useful for constructing covenants /en/newsletters/2022/02/16/#simplified-alternative-to-op-txhash title url Proposed `OP_EVICT` opcode to make covenants more efficient /en/newsletters/2022/03/02/#proposed-opcode-to-simplify-shared-utxo-ownership title url Discussion about the risks of allowing recursive covenants /en/newsletters/2022/03/09/#limiting-script-language-expressiveness title url When would enabling `OP_CAT` allow recursive covenants? /en/newsletters/2022/05/18/#when-would-enabling-op-cat-allow-recursive-covenants title url Updated `OP_TX` opcode useful for constructing covenants /en/newsletters/2022/05/18/#updated-op-tx-proposal title url Discussion about Miner Extractable Value (MEV) risk from recursive covenants /en/newsletters/2022/05/25/#miner-extractable-value-discussion title url Proposal to use covenants and merkle trees to enable generalized smart contracts /en/newsletters/2022/11/16/#general-smart-contracts-in-bitcoin-via-covenants title url Proposal for `OP_VAULT` and `OP_UNVAULT` opcodes to enable convenant-based valuts /en/newsletters/2023/01/18/#proposal-for-new-vault-specific-opcodes title url Proposal for alternative design for `OP_VAULT` inspired by `OP_TLUV` /en/newsletters/2023/03/08/#alternative-design-for-op-vault	title link An early description of covenants in Bitcoin https://bitcointalk.org/index.php?topic=278122.0 title link OP_CHECKSIGFROMSTACK topic op_checksigfromstack title link OP_CHECKTEMPLATEVERIFY topic op_checktemplateverify title link Vaults topic vaults

"In the context of Bitcoin, the most useful definition of covenant is that it's when the scriptPubKey of a UTXO restricts the scriptPubKey in the output(s) of a tx spending that UTXO." ---Anthony Towns ([source][towns covenant definition])

For example, a covenant may normally only allow spending to a whitelisted set of scripts, such as returning bitcoins to the user's own balance or spending to a staging address that only allows spending to any arbitrary address after a period of time.

{% include references.md %} [towns covenant definition]: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2022-January/019795.html