On January 8, 2009, at 19:27 UTC, Satoshi Nakamoto announced Bitcoin v0.1, its first public release, to the Cryptography Mailing List with the subject “Bitcoin v0.1 released.” The download link in that email already pointed to SourceForge, where he had registered the project two months earlier. SourceForge’s own file listing, as archived in 2010, dates the file bitcoin-0.1.0.rar to January 12.
This was a Windows-only release, written in C++, with open-source code included. The software allowed users to:
- Connect to the Bitcoin peer-to-peer network automatically
- Generate coins by contributing CPU power to the network
- Send and receive bitcoin transactions
- View transaction history
The send dialog in the v0.1.0 source asked for the recipient’s IP address “(e.g. 123.45.6.7) for online transfer with comments and confirmation, or bitcoin address (e.g. 1NS17iag9jJgTHD1VXjvLCEnZuQ3rJED9L) if recipient is not online.” The About dialog added: “This is experimental software. Do not rely on it for actual financial transactions.” The example address later received real coins. As of October 2026 it had received 102 payments totalling 900.85217683 BTC, none of them ever spent, beginning with 0.05 BTC on September 10, 2010, and including four payments in just over six minutes on January 26, 2011, of 100, 0.02, 19.73 and 777 BTC. Who sent them, and who holds the key to the address, is not on record.
Satoshi Nakamoto (Cryptography mailing list post, January 08, 2009, 7:27:40 PM UTC)Announcing the first release of Bitcoin, a new electronic cash system that uses a peer-to-peer network to prevent double-spending. It’s completely decentralized with no server or central authority.
Satoshi described the proof-of-work difficulty as “ridiculously easy to start with,” noting that a typical PC could generate coins in just a few hours. The total circulation was set at 21 million coins, gradually released to network nodes based on CPU power contributed. Satoshi restated this figure five weeks later in direct response to a question from Martien van Steenbergen on the P2P Research mailing list.
Block 1 was mined on January 9 at 02:54:25 UTC, marking the true beginning of the Bitcoin network’s continuous operation — the genesis block, Block 0, had already been hardcoded into this same v0.1 codebase six days earlier, on January 3. Hal Finney was among the very first to download and run the software, famously tweeting “Running bitcoin” on January 11, 2009, and receiving the first known Bitcoin transaction (10 BTC from Satoshi) on January 12. This launch week’s unusually dense pace of releases and private correspondence is itself explored in an analysis of where Satoshi may have been working from at the time.
