Tezos — a self-amending crypto-ledger White paper L.M Goodman September 2, 2014 “Our argument is not flatly circular, but something like it.” —Willard van Orman Quine Abstract We present Tezos, a generic and self-amending crypto-ledger. Tezos can instantiate any blockchain based ledger. The operations of a regular blockchain are implemented as a purely functional module abstracted into ashellresponsiblefornetworkoperations. Bitcoin, Ethereum, Cryptonote, etc. can all be represented within Tezos by implementing the proper in- terface to the network layer. Most importantly, Tezos supports meta upgrades: the protocols can evolve by amending their own code. To achieve this, Tezos begins with a seed protocol defining a procedure for stakeholders to approve amend- ments to the protocol, including amendments to the voting procedure itself. This is not unlike philosopher Peter Suber’s Nomic[4], a game built around a fully introspective set of rules. In addition, Tezos’s seed protocol is based on a pure proof-of-stake system and supports Turing complete smart contracts. Tezos is imple- mented in OCaml, a powerful functional programming language offering speed, an unambiguous syntax and semantic, and an ecosystem making Tezos a good candidate for formal proofs of correctness. Familiarity with the Bitcoin protocol and basic cryptographic primi- tives are assumed in the rest of this paper. 1