How it works
Halvenfall is an endless dark-fantasy chronicle written from the Bitcoin blockchain. Every block, about every ten minutes, becomes a chapter. The world is lit by a dying sun, the Lantern, whose gift halves every four years, as Bitcoin's block subsidy does, until it goes out around 2140.
Every block becomes a chapter
When a new block has one confirmation (one more block mined on top of it), the chronicler reads its real data: which pool mined it, how many transactions it carried, what they paid, how long it took to find. Nothing about the chain is invented. The story is invented around it.
The chronicler is an AI, given the block, the story so far and the world's rules. Most blocks are quiet and get a short vignette. Unusual ones get longer scenes, and rare ones get a full chapter. Every 144 blocks, about a day, a Book closes and gets its own tale.
The chain, in the Dimming
| On the Bitcoin chain | In the story |
|---|---|
| A block | A link of the Chain, and its chapter |
| A mining pool | A House that catches the light |
| A solo miner | A lone lamplighter, almost a miracle |
| The block subsidy | The Lantern's gift |
| Fees | Oil, which travellers pay for passage |
| A vbyte, and fee rates per vbyte | A span, the room a traveller takes aboard; passage costs so much a span |
| The mempool | The Throng waiting at the gate |
| Difficulty | The Veil, which thickens as more lamps burn |
| A halving | A Halvenfall, when the light halves and an Age ends |
| 144 blocks, about a day | A Book, which closes with its own tale |
| Fees as a share of the miner's reward | How self-lit the world is |
| The subsidy reaching zero, around 2140 | The Last Dark |
Omens
Each chapter lists the omens read from its block. They decide what the chapter is about. A few of them:
- Cheap passage, costly passage, dear passage, the oil-fever
- The block's median fee rate was very low, high, very high, or extreme.
- A rush for passage, the rush breaks
- Fees jumped, or fell back, against the links before.
- The long dark, the great dark
- Half an hour, or a whole hour, passed since the block before.
- A quick catch
- The block came only moments after the one before it.
- An empty link, a crowded link
- The block carried almost no transactions, or a great many.
- A lone lamplighter, a new house
- A solo miner found it, or a pool new to the chronicle.
- The Veil thickens, the Veil thins
- The mining difficulty adjusted up or down.
- Oil outshines the gift
- The fees paid to the miner were worth more than the subsidy.
- The Scribes' link
- Inscriptions and other data filled almost the whole block.
- Grey cloaks
- A large coinjoin: many people's coins moved together, so no one can tell who paid whom.
- Words in the link
- On a Halvenfall or a round-number link, someone wrote a message into the block itself (OP_RETURN or a text inscription), and it passed a check before being quoted.
- A great chest
- A single transaction sent at least 200 bitcoin onward (not counting what may be change).
Why the Lantern dims
Bitcoin's block subsidy halves every 210,000 blocks, about every four years. In the Dimming that's a Halvenfall: the Lantern's gift halves, an Age ends, and the world grows darker for good. The next one is 74,916 links away.
The sun at the top of every page is as bright as the real subsidy allows. The band beneath it shows all 33 Ages, from the first light in 2009 to the Last Dark around 2140, when the subsidy reaches zero.
How self-lit the world is
Miners earn the subsidy and the fees. The share that comes from fees is how self-lit the world is: light the Houses earn from travellers rather than receive from the dying Lantern. Over the last 144 links it was 0.6%.
When it rises, the story drifts toward the Long Dawn, the hope that the world can live on its own fire. When it falls, the Houses go hungry and the Glare's endless printed light sounds sweeter. No one writes the ending. The chain does.
The live line and the newest link
The line under the sky is live. Travellers waiting at the gate are unconfirmed transactions in the mempool, passage is the fee rate to get into the next block, and the time the Veil has held is the time since the last block. When a new chapter is written, the front page forges it onto the chain without a reload.
The Wakeful's mark
A few chapters in every Book carry the Wakeful's mark, a short note in the margin. An AI reader scores every chapter on whether something happens in it, whether it uses its block, and whether it says something new; when a Book closes, its best few are marked, and some Books get none. The front page shows them first, so you can start with the best rather than the newest. The mark is ours. Candles are yours.
Candles
If a chapter moves you, light a candle on it: ₿21 over Lightning, or a bigger candle for whatever you think the link is worth, from any wallet, with no account. Every chapter shows how many candles were lit for it. Candles go to Halvenfall's wallet and help pay for the writing.
Amounts here follow BIP 177: ₿1 is the smallest unit of bitcoin, what used to be called a sat. So ₿21 is 21 of them.
For machines
Every chapter is also plain Markdown: add .md to its address, as in/block/975084.md. Closed Books come as an RSS feed, one a day. /llms.txt describes the site for language models, and /llms-full.txt holds the world, the last Book's tale and the latest chapters in one file.
Read the newest link or begin with the prologue.