Cardano (ADA)
A blockchain that upgrades in named eras and now governs itself by on-chain vote, set out as facts from its genesis file and improvement proposals.
On this page
- Cardano's mainnet genesis file sets its start at 23 September 2017, 21:44:51 UTC.[1]
- The genesis file caps supply at 45,000,000,000,000,000 lovelace, the unit the ledger counts in.[1]
- Cardano upgrades through named eras: Byron in 2017, Shelley in 2020, then Allegra, Mary, Alonzo, Babbage and Conway.[2]
- Since the Chang hard fork in September 2024, Cardano runs in the Conway era built for on-chain governance.[2]
- CIP-1694 gives votes to three bodies: a Constitutional Committee, delegated representatives and stake pool operators.[3]
What is Cardano and who shapes it?
Cardano is a public blockchain, and ADA is its native asset. The mainnet genesis file, the configuration every node starts from, records a system start of 23 September 2017 at 21:44:51 UTC.[1] Cardano's own terminology splits its development into high-level phases (Byron, Shelley, Goguen and Voltaire) and into ledger eras, each introduced at a hard fork.[2]
Changes are written up as Cardano Improvement Proposals, or CIPs. The proposal that created today's on-chain governance, CIP-1694, was created on 18 November 2022 by six authors, among them Charles Hoskinson.[3] Under the earlier Shelley-era scheme, governance actions needed authorisation from 5 of 7 governance keys on mainnet.[3] The primary sources we checked do not set out a founding story, so this profile does not name a single creator. For the consensus family Cardano belongs to, see proof of work vs proof of stake.
How does the Cardano network work?
Cardano divides time into slots of one second and groups 432,000 slots into an epoch.[1] Its consensus protocol has changed over time: Ouroboros Classic at launch, Ouroboros BFT from February 2020, Ouroboros Praos from the Shelley era in July 2020, and Ouroboros Genesis/Praos from the Chang hard fork in September 2024.[2]
How are new ADA created and spent?
Cardano's supply limit is written into its genesis file as a maximum of 45,000,000,000,000,000 lovelace.[1] The figure is given in lovelace, the unit the ledger counts in, and we do not convert it because the sources we used do not state the conversion. The ledger also keeps a reserve and a treasury: CIP-1694 describes ada moving out of the reserves and the treasury, and between the two.[3]
Under CIP-1694, a treasury withdrawal is one of seven governance actions and needs ratification before it takes effect.[3] The formula that pays staking rewards out of the reserve is set by protocol parameters; the primary sources we used do not explain it, so we do not quote a reward rate. Read what is staking for the general idea.
What is ADA used for?
- Voting power. CIP-1694 rests on the principle of one lovelace, one vote, so governance weight comes from ada delegated for that purpose.[3]
- Deposits. The genesis file sets a key deposit of 2,000,000 lovelace and a pool deposit of 500,000,000 lovelace, 250 times larger by our arithmetic.[1] Anyone submitting a governance action posts a deposit that is returned when the action is finalised.[3]
- Fees. Transaction fees are set by protocol parameters, named minFeeA and minFeeB in the genesis file.[1]
What are the key dates in Cardano's history?
Month-level dates come from the feature table in CIP-0059; the exact start time is from the mainnet genesis file.
| Date | Event |
|---|---|
| 23 September 2017 | Mainnet system start, Byron era[1] |
| February 2020 | Switch to Ouroboros BFT[2] |
| July 2020 | Shelley era begins, Ouroboros Praos[2] |
| September 2021 | Alonzo era begins[2] |
| September 2022 | Vasil hard fork, Babbage era[2] |
| 18 November 2022 | CIP-1694 governance proposal created[3] |
| September 2024 | Chang hard fork, Conway era[2] |
| January 2025 | Plomin hard fork[2] |
| July 2026 | van Rossem hard fork[2] |
What are the specific risks of holding ADA?
- Rules set by vote. Protocol parameter changes, hard forks and treasury withdrawals are all governance actions under CIP-1694,[3] so the rules that affect holders can change after a vote.
- Frequent hard forks. CIP-0059 lists protocol versions from 0 to 11 between 2017 and 2026,[2] and each hard fork changes the ledger rules. See fork.
- Concentrated control in the past. Before on-chain governance, actions needed 5 of 7 governance keys.[3] Whether the new system spreads power widely depends on how holders delegate their votes.
- Custody. Lost or hacked self-custody wallets can mean permanent loss; custodians can be hacked or go bankrupt.[4]
What mistakes do beginners make with ADA?
- Reading lovelace figures as ADA. Protocol files count in lovelace,[1] so a raw figure such as the 2,000,000 key deposit is a lovelace amount, not an ada amount; check the unit before quoting a parameter.
- Assuming genesis values still apply. Protocol parameters can be changed by a governance action,[3] so values in the 2017 genesis file may not be current.
- Treating a governance deposit as a fee. It is returned when the action is finalised.[3]
- Mixing up eras and hard forks. Babbage is an era; Vasil and Valentine are hard forks inside it.[2] Our guide to reading a whitepaper helps with technical documents.
Questions readers ask
Does ADA have a maximum supply?
Yes. The mainnet genesis file sets a maximum of 45,000,000,000,000,000 lovelace.[1]
How long is a Cardano epoch?
432,000 one-second slots,[1] which by our arithmetic is 5 days.
Who votes on changes to Cardano?
Under CIP-1694, a Constitutional Committee, delegated representatives (DReps) and stake pool operators; most actions need two of the three bodies, and hard forks need all three.[3]
What era is Cardano in now?
The Conway era, which began with the Chang hard fork in September 2024; the van Rossem hard fork in July 2026 stayed within Conway.[2]
Cardano is defined by a fixed maximum supply in its genesis file,[1] a steady sequence of era upgrades,[2] and, since 2024, governance by on-chain vote.[3] For a holder, the practical question is less about the code than about who votes, and on what, as parameters and the treasury come under that vote.
Sources
- Intersect (IntersectMBO/cardano-node), Cardano mainnet Shelley genesis file (configuration/cardano/mainnet-shelley-genesis.json) (2026)Primary source
- Cardano Improvement Proposals (cardano-foundation/CIPs), CIP-0059: Terminology Surrounding Core Features (feature table) (2022)Primary source
- Cardano Improvement Proposals (cardano-foundation/CIPs), CIP-1694: An On-Chain Decentralized Governance Mechanism for Voltaire (2022)Primary source
- US Securities and Exchange Commission (Investor.gov), Crypto Asset Custody Basics for Retail Investors (2025)Primary source
Educational content only — not financial, investment, legal or tax advice. Crypto-assets are high-risk and you could lose all the money you put in. Rules differ by country; check with your national regulator. See our risk disclosure and editorial policy.
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