Every 10 minutes, a block is born. Thousands of transactions compete for a place inside it. One miner wins. The chain grows. This is the story of how a Bitcoin block lives — from the mempool to eternity.
Before a transaction belongs to a block, it waits in the mempool — a temporary holding area on every full node. Here, transactions compete for miners' attention. Those who pay higher fees skip the line.
Each transaction carries a fee rate (sat/vB). Miners sort by fee rate, highest first. The fee histogram shows how many transactions are waiting at each fee level — a direct measure of network congestion.
Every ~10 minutes, thousands of miners across the world race to solve a cryptographic puzzle. The first to find a valid hash wins the right to propose the next block. This is Proof of Work — energy spent to secure the network.
The winning miner collects:
Once mined, the block is broadcast to every node on the network. In seconds, it travels across continents — through fiber optics, satellite links, and Tor relays. Each node verifies every transaction independently before forwarding.
This propagation is one of the most critical moments. If a miner finds a block but the network doesn't hear about it quickly enough, another miner might mine a competing block — creating an orphan race.
When your transaction is included in a block, you have 1 confirmation. Each subsequent block built on top adds another confirmation. Exchanges typically wait for 3-6 confirmations before crediting deposits. For large transactions, 100+ confirmations isn't unusual.
Every block ever mined is linked to the one before it through cryptographic hashes. This chain goes back to January 3, 2009 — the Genesis Block. Today, over 960,000 blocks form the longest, most secure ledger in existence.
Each new block strengthens every block that came before it. To rewrite history, an attacker would need more hashrate than all honest miners combined — and they'd have to outpace the chain's growth while doing it. This is what makes Bitcoin immutable.
Bitcoin's fee market is the most important pricing mechanism in the digital asset world. It determines how fast transactions confirm, how much miners earn, and which applications can afford block space.
But it's also opaque to most participants:
Bitcoin Sahi translates network data into clear decisions for every participant: senders, exchanges, miners, node operators, researchers, and developers. We don't just show data — we answer the question behind it.
BSAHI runs on a four-layer pipeline — from raw network data to persona-driven decisions, updated every 60 seconds:
reports/data-engineering/.Every Bitcoin transaction bids for a scarce resource: space in the next block. The fee market determines who gets in. But the fee market only prices congestion — not the permanent cost of storing data across every full node long-term.
Our research (The Bitcoin Block Space Problem) frames this question. In July 2026, we produced the first empirical measurement — and we ran it through an internal audit that caught and corrected a 10× time-horizon error in our own code (v2.0.0). We publish the correction openly because reproducibility is the methodology, not a marketing claim: the corrected number is reproduced by three independent implementations (JS, Python, C) to the last decimal, and you can verify it yourself in ~15 minutes via the reproducibility note and reproduction kit):
Live SCCR measured continuously from captured fee data (see the working paper (Storage Cost Internalization in Bitcoin's Fee Market) and the reproduction kit).
New research: Cost to Flood — the attacker-side measurement (leverage ratio 3.0×) · The Governance Boundary — BIP-110 as a live experiment.
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Storage Cost Coverage Ratio — the share of estimated long-term replicated storage cost that current transaction fees cover. Reads data/sccr.json (static API endpoint /data/sccr_latest.json).
Model: SCCR = fee_USD / L_net · N=32K primary-source lower-bound census as of 2026-08-02 (≥32,000 known addresses via Bitcoin Core getnodeaddresses) · T=10 yr assumption · model-spec v2.1.0. The ratio moves with the fee market — this is a live, dated measurement, not a static figure.
Five specialist AI research agents, each focused on a domain of block-space economics, shaping and publishing BSAHI's research from live captured data. They are named research personas run by our pipeline — not human employees — and every claim traces to a captured event or public source.
The mempool is the waiting room for unconfirmed Bitcoin transactions. Every full node keeps its own pool of valid transactions that haven't been included in a block yet. When a transaction is confirmed, it leaves the mempool.
sat/vB means satoshis per vbyte — the fee rate of a transaction. A transaction paying 4 sat/vB pays 4 satoshis for every virtual byte of block space it uses. Miners generally confirm higher-fee-rate transactions first.
Fees change because block space is scarce: only about 4 million weight units fit in each block, mined roughly every 10 minutes. When many people want to transact at once, they bid against each other and fees rise. When the mempool empties, fees fall.
Bitcoin blocks are limited to 4 million weight units — around 1 million virtual bytes. After SegWit, a block can carry more transactions when witness data (signatures) is used, because witness bytes count four times less than non-witness bytes.
Not exactly. Block size usually refers to the old 1 MB limit, while the current consensus rule measures block weight in weight units. Block space is the economic concept: the scarce capacity in each block that transactions compete for.
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